N^o. 97 TELEGRAPHIC DETERMINATION LONGITUDES IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, AND ON THE NORTH COAST OF SOUTH AMEEICA. 1888-1889-1890. Cornell University Library QB 229.U58 1888-90 Telegraphic determination of longitudes 3 1924 012 320 200 The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924012320200 No. OV.y 5, BUREAU OF NAVIGATION— liYDKdGRAPHIC OFFICE. TELEGRAPHIC DETERMINATION LONGITUDES IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, AND ON THE NORTH COAST OF jQUTH AMERICA, .i/.^.^^/^ y/ [UAN DEL SUR; ST. NICOLAS VO; AND LA GUAYRA, RICHARDSON CLOVER, -5";.../ -^...........^,, /f, ^' ;^,,,^_ STATIONS. ^^ ^^ '^ [,ES LAIED, U. S. N. A REPORT ON MAGNETIC OBSERVATIONS MADE AT VKRA CRUZ; COATZACOALCOS; SALINA CRUZ; PORT PLATA; CURASAO; AND LA GUAYRA. BY .leut. CHARLES LAIRD and Ensigns J. H. L. HOLCOMBE and L. M. GARRETT, U. S. N. PUBLISHED IIY OKDF^l OK COMMODORE T. M. RAMSAY, U. S. N., CHIEF OF BUREAU OF NAVIGATION, NAVY DEPARTMENT. WASHINGTON: GOVERNMENT PRINTING OFFICE. 18 9 1. No. 97.^ 5_ BUREAU OF NAVIGATION— HYDROGRAPIIIC OFFICE. TELEGRAPHIC DETERMINATION OF LONGITUDES IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, AND 0^f THE NORTH COAST OF SOUTH AMERICA, EMBRACING THE MERIDIANS Ol' COATZACOALCOS; SALINA CRUZ; LA LIBERT AD; SAN JUAN DEL SUR; ST. NICOLAS MOLE; PORT PLATA; SANTO DOMINGO; CURACAO; AND LA GUAYRA, WITH THE LATITUDES OF THE SEVERAL STATIONS. BY LIEUTENANTS J. A. NOREIS AND CHARLES LAIED, U. S. N. TO WHICH IS APPENDED A REPORT ON MAGNETIC OBSERVATIONS MADE AT VERA CRUZ; COATZACOALCOS; SALINA CRUZ; PORT PLATA; CURASAO; AND LA GUAYRA. BY ieut. CHARLES LAIRD and Ensigns J. H. L. HOLCOMBE and L. M. GARRETT, U. S. N. PUBLISHED BY ORDbV OF COMMODORE 'f. M. RAMSAY, U. S. N., CHIEF OF BUREAU OF NAVIGATION, NAVY DEPARTMENT. WASHINGTON: GOVERNMENT PRINTING OFFICE, 18 9"l. ^k'-¥f-irerj A. univer^jsty LIBRARY CONTENTS INTRODUCTION. Page. General Introduction 5 Description op Stations 16 Description of Instruments .~ 19 Instrumental Constants 21 Methods of Observation 22 Personal Equation 25 Methods of Reduction 25 observations. Observations for Time 29 Observations for Latitude 100 results. Final Chronometer Corrections 114 Differences op Chronometers prom Exchange op Time Signals 117 Differences op Longitude 120 Resulting Latitudes and Longitudes 123 appendix. Report on Magnetic Observations 127 3 INTRODUCTION. GENERAL INTRODUCTION. In continuation of the work of establishing secondary meridians by telegraphic measurement of differences of longitude, an expedition was sent out in 1883 by the Bureau of Navigation of the Navy Department, of which Bureau Commodore J. G. Walker, U. S. Navy, was at that time chief. A report of the work accomplished by this expedition, which was in charge of Lieut. Commander (now Commander) C. H. Davis, U. S. Navy, was published in 1885.^ The object was to measure over the telegraph lines extending from Galveston, Tex., down the Gulf-coast of Mexico, across the Isthmus of Tehuantepec, and thence down the west coast of Central and South America to Valparaiso. This plan was carried out with the exception of the measure- ment between Vera Cruz, on the Gulf of Mexico, and La Libertad, on the Pacific coast of Central America. The delay, which would have been caused by crossing the Isth- mus of Tehuantepec, where the methods of transportation were known to be primitive, or by going around via the Isthmus of Panama, would have seriously interfered with the remainder of the work, and this portion of the measurement was left to be completed at some future time. The positions of Vera Cruz and La Libertad were carefully es- tablished; the former from Galveston, and the latter from Panama. Upon the con- clusion of this work the instruments were stored away at the Naval Observatory, and the officers employed were detailed for sea service. In the spring of 1888 it was decided by Commodore Walker, who was still Chief of Bureau of Navigation, upon recommendation of the hydrographer, Commander J. R. Bartlett, U. S. Navy, to complete this chain of measurements by putting in the omitted links, and thus furnishing a verification of the positions on the west coast of Central and South America. Lieut. J. A. Norris, who had been an observer in the former expedition, was placed in charge of the work, with instructions to collect the outfit of instruments and supplies Lieut. Charles Laird, another member of the former party, was detailed as an observer. ;^r^^ZZ;b^^i;^^in>^tion of Longitades in Mexico and Central America, and on the West Coast of South America' by Lieut. Commander C. H. Davis and Lieuts. J. A. Norris and Charles Laird m 1883 and 1884. Bureau of Navigation, Washington. 1885. 5 6 TELEGRAPHIC DETERMINATION OF LONGITUDES Application was made througli the Department of State to the Governments of the several countries for permission to land instruments and make observations at the desirable points. These were Vera Cruz, Coatzacoalcos, and Salina Cruz, in Mexico; La Libertad, in Salvador, and San Juan del Sur, in Nicaragua. The last-named point was not in the regular chain of measurements, but it was considered desirable to de- termine its position, as it was in the immediate vicinity of the Pacific terminus of the proposed Nicaragua Canal. The required permission was promptly and cheerfully granted by the Grovernments of the countries concerned. Permission to use the telegraph lines of the Mexican and Central and South Ameri- can telegraph companies for the exchange of time signals was asked and cordially granted; and to the assistance rendered by the employees of these companies, under orders from the main office in New York, much of the success of the work is due. As the most favorable period for astronomical work in the portion of the tropics to be visited is during the winter or dry season, it was not desirable that the expedi- tion should start until about the middle of November. This gave plenty of time for preparation, and the summer was passed in overhauling, cleaning, repairing, and test- ing the instruments formerly in use. These were found to be. generally in fair condi- tion, and, with the exception of the chronographs, were easily put in condition for use. The chronographs were found to be considerably out of repair, and being of an anti- quated pattern, difficult of adjustment, it was decided to replace them with new ones. The model used by the U. S. Coast and Greodetic Survey was selected, and two of the instruments were purchased from Fauth & Co , of Washington. In consequence of the necessity of crossing the Isthmus of Tehuantepec it was desirable to make the outfit as light as possible, and for this reason a tent was designed for astronomical work, to be used instead of the wooden observatories which had served in all preceding expeditions. One of these tents was supplied to each observing party and in use was found to possess all the desired qualities of convenience, stability, and lightness. Ordinary wall tents were also procured to be used as lodgings for the observers at points where it might be difficult or impossible to find inhabitable houses. Soon after preparations for the field were begun, Commander Bartlett was detached from the Hydrographic Office and his place was taken by Lieut. George L. Dyer, U. S. Navy, who had been assistant hydrographer. Lieutenant Dyer took great interest in the work, was untiring in his efforts to supply the needs of the expedition, and placed at the disposal of Lieutenant Norris all the available resources of his office. It resulted from this that the outfit was very complete and work in the field was much facilitated. At his suggestion a set of instruments for magnetic observations, consist- ing of a magnetometer and a dip circle, was included in the list of instruments. During the progess of these preparations a communication was received by the Navy Department from M. Fressinet, the manager of the Soci^t^ Fran9aise des Tele graphes Sous-Marins in the West Indies, offering the use of the cable, which had just been completed, for the measurement of longitudes. This cable extends from Santiago de Cuba through Hayti, San Domingo, and CuraQao to La Guayra in Venezuela. As the preparations for the work in Mexico and Central America were so far advanced it was decided to proceed with that measurement and to accept the liberal offer of the French company for the following season. m MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 7 Shortly before the date set for departure from the United States, Ensigns J. H. L. Holcombe and S. S. Wood, U. S. Navy, were detailed as assistants, and on November 1 7, 1 888, the entire party sailed from New York for Vera Cruz in the Ward Line steamer City of Washington. The voyage was pleasant, but rather long, owing to delays at the numerous ports touched by the steamer. Vera Cruz was finally reached on December i. A heavy norther was just setting in, and though the members of the party succeeded in getting ashore, it was not possible to land the instruments for several days afterward. The officials of the custom- house had received instructions from their Grovernment to allow the free entry of the effects of the expedition, and there was no delay experienced in getting possession of them after they were landed. As soon as possible after landing official calls were made on the city authorities, who promptly granted permission to erect the observatory and courteously offered any assistance in their power. The expedition was greatly indebted at this point to Mr. H. Millard, the manager of the cable office, for many acts of kindness and courtesy. He was untiring in his efforts to aid the party in every way in his power. It had been intended that one observing party should proceed immediately to Coatzacoalcos, while the other was making preparations for work at Vera Cruz. It was found, however, that the only steamer which plied between these ports had just left Vera Cruz, and the time of her return was problematical. She did not, in fact, arrive until the 1 5th of December, and was not ready for her return trip to Coatza- coalcos until the 2 1 St. The time was occupied in setting up the observatory and instruments and making preparations for work. The site occupied by Lieutenant Commander Davis in 1883 was easily found. His pier had been left standing, and though considerably dilapidated and weather beaten, had not been moved from its original position. It was repaired with little trouble, the wooden observatory was set up around it, and the instruments mounted and adjusted. Lieutenant Laird assumed charge of this station, with Ensign Holcombe as his assistant. For use as a magnetic observatory the astronomical tent was set up on a square of open ground known as Baluarte Santiago near the southern limit of the city. Magnetic observations were begun as soon as these preparations were completed. As soon as possible after the arrival of the steamer the outfit belonging to the Coatzacoalcos party was put on board, and on December 2 1 Lieutenant Norris and Ensign Wood sailed for that port. The steamer was small and indescribably dirty and uncomfortable, and the trip was exceedingly disagreeable, though fortunately of short duration, as the destination was reached the next morning. Upon arriving the party was met by Mr. F. W. Carpenter, the manager of the cable office, who had made all arrangements for landing the instruments, etc. Like all employes of the telegraph company with whom the expedition came in contact, he was untiring in his efforts to aid in every possible way, and his assistance was of the greatest value. Coatzacoalcos is a small town about 120 miles from Vera Cruz in a southeasterly direction. It is situated on the left bank of the river of the same name, which here flows nearly due north. It is only a short distance from the mouth of the river. A range 8 TELEGKAPHIC DBTBRMmATION OF LONGITUDES of low sand hills lies between the town and the Gulf. A light-house is situated on one of the highest of these hills neai- the mouth of the river. The site for the observatory was chosen near the center of the town about 350 yards to the south and west of the light-house. The transit pier was built of bricks and Portland cement, and the wooden observatory was set up around it. For com- munication with the telegraph office, about a third of a mile distant, an insulated wire was extended on poles. The transit and other instruments were mounted and adjusted and all preparations for work were finally completed on December 28. The weather on the Gulf coast of Mexico during the winter months is generally unfavorable for astronomical work owing to the frequent northers, which last anywhere from three days to a fortnight. These gales are of more or less violence, but always bring thick clouds and rain, and while they continue it is next to impossible to make star observations. After one gale ends and before the next one begins there are generally a few days when the wind is from the southward and the weather is fine. These were almost the only favorable opportunities for observation and every advantage was taken of them. The cable between Vera Cruz and Coatzacoalcos being short, the ordinary Morse telegraph instruments were in use, and it was possible to make an automatic exchange of time signals for the comparison of the chronometers. Whenever the weather remained clear, after the night's longitude work was completed, a number of observations were made for the determination of latitude. The stations being so near together and on the same coast, the weather conditions were similar, and when it was possible to observe at one place it was generally clear enough at the other also. The measurement was finally completed on January 17, 1889, observations having been made and time signals exchanged on six nights, viz, December 29 and 30, January 12, 15, 16, and 17. Lieutenant Laird was then directed to proceed to Coatzacoalcos with his party and instruments by the first opportunity, and Lieutenant Norris made preparations for the journey across the Isthmus of Tehuantepec to Salina Cruz. As the wooden observatory could not be transported it was left standing for the use of Lieutenant Laird, who was directed to ship it to the United States when he had completed his work. A like disposal was made of his observatory in Vera Cruz. Before dismounting the instruments a meridian mark was placed on the brow of a hill north of the observatory for the convenience of Lieutenant Laird in adjusting his transit. A spot for his magnetic observatory was also selected and marked. The bearing and distance of the light-house from the transit pier were obtained by triangu- lation. The instruments were then packed and all preparations were made for the journey. In crossing the isthmus the intention was to proceed up the Coatzacoalcos River in canoes as far as the small native village of Suchil, about a hundred miles. There a train of twenty-five pack mules was to be in waiting to transport the instruments, etc., another hundred miles to the town of San Geronimo, which was the terminus of the railway to Salina Cruz. This plan was successfully carried out. Progress on the river was slow, as the canoes had to be poled against the current, which in places was very swift. On the 2 2d of January the party left Coatzacoalcos and did not reach IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 9 Suchil until the evening of tlie 29th. The mule train arrived the next evening and and on the morning of the 31st a start was made for San Geronimo. The route for the first day was over a rough and muddy road, througli the tangled intricacies of a tropical forest The mules being heavily laden, some of the instrument boxes weighing nearly 300 pounds, the rate of travel was necessarily slow. After the first day's journey a much better road was found, as it was on the line of the telegraph wire where the ground was kept clear of undergrowth. On the third day from Suchil the telegraph station at the village of Sarabia was reached, where the party was hospitably received by the station manager. A telegram was received here notifying Lieutenant Norris that Lieutenant Laird and party had arrived at Coatzacoalcos. San Greronimo was reached on the evening of February 5. This town was the headquarters of Mr. F. Van Valkenburgh, the isthmus superintendent of the cable company. The party was received and entertained with the utmost hospitahty by this gentleman and his charming wife. The train for Salina Cruz left on alternate days, which gave the party a needed rest until the 7th. On that day a start was made at an early hour in the morning and the final destination was reached in the evening. A stop was made at the city of Tehuantepec, and in company with the United States consular agent, Mr. Albert' Langner, an official visit was paid by Lieutenant Norris to the Jefe Politico of the city. Salina Cruz is the port of Tehuantepec and consists of a small collection of huts occupied by fishermen and laborers. The only houses of consequence belong to merchants who visit the place occasionally to superintend the loading or discharge of their ships. Nothing in the shape of a hotel or lodging house exists. The cable house is on the beach nearly a mile from the town. It is a commo- dious structure of corrugated iron containing several rooms. It had been at one time used as an office and occupied by the corps of operators, but the office had been removed to Tehuantepec and it was vacant. Mr. Van Valkenburgh kindly gave the party permission to use it, arrangements were made with the proprietor of a hotel in Tehuantepec to supply meals, and the observers found it a very comfortable habitation. A suitable site for the observatory was found near the house, inside the grounds belonging to it, a pier was built of bricks and mortar, and the astronomical tent was set up. Everything was ready for work on the evening of February 9, but owing to bad weather in Coatzacoalcos signals were not exchanged until the following night. During the stay of Lieutenant Norris in Salina Cruz the weather was clear and, for astronomical work, nearly perfect. The northerly winds, which blow at that season almost constantly, seem to leave all their clouds and moisture on the north side of the ridge which extends from east to west across the isthmus. In Coatzacoalcos the weather continued more or less cloudy and rainy, but Lieutenant Laird succeeded in making observations on the nights of February 10, 12, 13, 14, 15, and 16, and the successful exchange of time signals on these nights rendered the measurement complete. Lieu- tenant Laird was then directed to proceed across the isthmus as soon as possible and occupy the Salina Cruz station, while Lieutenant Norris was on his way to La Libertad. After the completion of the longitude work at Salina Cruz, about ten days elapsed before the arrival of the steamer. This interval was employed in making latitude 10 TELEGEAPHIO DETEEMINATION OP LONGITUDES observations, and in referring the position of the observatory to that of the observation spot on the Hydrographic Office Chart. The exact position of this spot was not shown, but it was referred to as being on the summit of the Morro Salina, a low hill near the village. A signal was placed on top of this hill, as near the center as possible, and a base line was measured near the observatory. From this the bearing and distance were obtained by triangulation in the usual way. On February 26, Lieutenant Norris and party embarked on the Pacific Mail steamer ChjtU and sailed for La Libertad. The distance is not more than 600 miles, but numerous stops were made, and much time consumed in taking in cargo, so that it was not until March 6 that the destination was reached. As usual the party was received by the Grovernment officials with great cordiality and many offers of assistance. No delay occurred in landing the instruments and passing them through the custom- house. As this station had been occupied by Lieutenant Laird during the expedition of 1883-84, a search was at once made for the transit pier which he had left standing. It was easily found from his description of the locality, but it was in a dilapidated condition, and had been moved from its original position. The plot of ground in which it stood had been converted into a corral for cattle and was consequently very dirty and unpleasant. It being necessary to build a new pier it was decided to select a more agreeable site, which was found in the yard in front of the telegraph office. The pier was built of bricks and cement, the observatory was set up, and the instruments mounted as soon as possible. As the spot selected for the pier was only a short distance from the beach, upon which there was frequently a very heavy surf, experiments were made to ascertain whether there was any perceptible tremor from this cause, but nothing of the kind could be detected. A careful triangulation was made to fix the bearing and distance between the old and the new piers. Lieutenant Laird arrived in Salina Cruz on March 7, and was ready for work on the loth. By this time the rainy season was approaching and there were signs of a change in the weather. It was frequently quite cloudy at night in La Libertad, and in Salina Cruz there were several showers No great delay was caused, however, and successful observations were made and signals exchanged on the nights of March 12, 13, 14, 16, 17, and 18, which completed the measurement. The mirror galvanometer was used in the exchange as the length of the cable precluded the use of the automatic method. No latitude observations were made here, the latitude having been determined by Lieutenant Laird on the former expedition. After the completion of the work at La Libertad, several days were consumed waiting for the steamer to San Juan del Sur. At that season of the year La Libertad was not at all a pleasant abiding place. The heat was excessive both day and night and high mountains north of the town completely shut off all breeze. No rain had fallen for months, and the dirt in the streets was continually stirred up by the teams bringing coffee from the surrounding country. On March 26, the Pacific Mail steamer Starbuch arrived, and the party lost no time in getting on board of her. San Juan del Sur was reached on March 29. The party was met on the steamer by the manager of the cable office, Mr. James Tiddy. He had been notified by tele- graph from La Libertad, and had made all possible arrangements to facilitate the work. IN MEXICO, CENTRAL AMEEICA, THE WEST INDIES, ETC. H A site for the observatory was selected in the grounds belonging to the cable company, and a pier was built immediately ; the observatory and instruments were set up and everything was ready for work on the night of March 30. Observations were made and signals successfully exchanged on March 30, 31, April i and 2. This concluded the work of the season. The instruments were dismounted and packed after the latitude oliservations had been made, and were shipped by freight to New York. Lieutenant Laird was directed to proceed with his party to Washington by the most practicable route. On April 9 Lieutenant Norris and Ensign Wood em- barked on the Pacific Mail steamer (ydij of Panama for New York via the Isthmus of Panama. After a pleasant trip the party arrived in New York on April 25, and pro- ceeded at once to Washington. Lieutenant Laird took passage to Acapulco, Mexico, in the coasting steamer of the Pacific Mail Line, and thence to Panama in the through steamer from San Fran- cisco, arriving in New York on the 1 5th of May. Work on the preliminary computation of the observations was at once begun. Lieutenants Norris and Laird reducing their respective time observations, Ensign Holcombe the magnetic work, and Ensign Wood the latitude. The summer of 1889 was occupied by this work, and by the necessary prepara- tions for the expedition to measure over the lines of the French company in the West Indies. As soon as the instruments arrived from Central America they were over- hauled and repairs made where needed. Such slight additions were made to the outfit as experience had shown to be desirable. What prove'd to be a very important addi- tion was a large tent, which was procured Ijy requisition from the War Department. It was known that the means of communication between some of the ports in the West Indies that it was desirable to visit were imperfect and unreliable, and it was decided by the Navy Department to detail one of the men of war of the North Atlantic fleet for the use of the expedition. The U. S. S. Yantic, Commander C. H. Rockwell, U. S Navy, commanding, was selected and proved to be admirably adapted for the purpose. During the summer Ensigns Holcombe and Wood were detached from the party, and Ensio-ns L. M. Garrett and H. B. Wilson were detailed in their places. On November 5, 1889, the expedition sailed from Washington on the U S. S. Despatch for Hampton Roads, where the Yantic was in readiness. This point was reached the next morning; tlae instruments and party were transferred immediately, and the same afternoon the Yantic sailed for Santiago de Cuba. At about the time of departure of the expedition Commodore Walker was suc- ceeded as Chief of Bureau of Navigation by Commodore F. M. Ramsay, U. S. Navy, and shortly after the hydrographer, Lieutenant Dyer, was relieved by Capt. Henry F. Picking, U. S. Navy. The lines of the Frencli cable company started from Santiago and extended to St Nicolas Mole, on the northwest point of Hayti, thence to Port Plata, on the north coast of the same island, in the Republic of San Domingo. A land hue connected this point with the City of Santo Domingo, on the south side of the island. From Santo Domingo a cable extended to the island of CuraQao, and thence to La Guayra, in Venezuela. 12 TELEGRAPHIC DETERMINATION OF LONGITUDES After a pleasant voyage the Yantic arrived at Santiago de Cuba on the 14th of November. As soon as possible a call was made upon the local authorities by Com- mander Rockwell and Lieutenants Norris and Laird, accompanied by the United States consul. It was found that as yet no notification as to the expedition had been received from the Spanish Government, but upon telegraphing to the governor general, at Havana, he at once sent instructions to show the party every attention and to rendei- all assistance required. The office of the cable company was also visited. M. Fressinet was absent, but M. Pouye^s, the manager of the office, received the party with great politeness and cheerful offers of assistance. The position of Santiago de Cuba had been telegraphically determined in 1874 by the first expedition sent out by the Bureau of Navigation, under the command of Lieut. Commander (now Commander) F. M. Green, U. S. Navy. Lieutenant Norris had been a member of that party and was acquainted with the locality of the observation spot. This was about a half-mile south of the city near a small fortification known as Blanca Battery. The original transit pier had been removed, but it was found that a pier of masonry had been erected and left standing in nearly the right spot by some party of Spanish or Cuban surveyors. This was accordingly made use of by Lieutenant Laird, who was left in charge of the station, with Ensign Garrett as his assistant. As soon as the Yantic had taken in a supply of coal and other necessary stores, a start was made for St. Nicolas Mole, Hayti, on November 1 7. This port was reached on the following evening, and" the next day Commander Rockwell asked and obtained permission from the local authorities to land the instruments and make the observations. A suitable site was selected near the telegraph office, and the pier was erected as soon as possible. St. Nicolas Mole is a small village, having little communication with the outside world. Supplies of any kind except fruit are difficult if not impossible to obtain. No suitable lodgings wei'e to be had, so the large army tent was set up on the beach near the observatory, and proved a very comfortable habitation. Lieutenant Norris had completed preparations for work on the night of the 23d November, but on the day preceding a telegram was received from Lieutenant Laird saying that he was ill with malarial fever, and would not be able to work for some days. Fortunately the attack was not serious, and he had recovered sufficiently to observe on tlie 25th. It had been hoped that time signals might be exchanged over this link by tlie automatic method, as the cable was short and in good condition. It was not found practicable, however, with the instruments possessed by the expedition, and use was made of the mirror galvanometer. Two or three nights were consumed in the attempt to work with the automatic system, but on the 28th it was abandoned and the mirror was successfully substituted. The weather was generally good, and no trouble was found in observing stars at either station. On the nights of November 28, 29, 30, December i, 2, and 3, observations were made and signals exchanged, com- pleting the measurement. It had been the intention to make magnetic observations at Santiago de Cuba, but on account of the poor state of health of Lieutenant Laird, and the fact that yellow IN MEXICO, CENTRAL AMERICA, THE WEST INJDIES, ETC. 13 fever had just broken out in the city, one of the first victims being M. Pouy(^s, of the cable company, it was deemed advisable for the party to leave the station with as little delay as possible. The magnetic observations were therefore reluctantly abandoned. On the 4th of December the Yantic sailed for Santiago, took Lieutenant Laird and party on board and conveyed them to Port Plata, arriving at that point on the 9th. While at Santiago, Commander Rockwell received instructions from the Navy Depart- ment to survey a small harbor on the south coast of Cuba, and as soon as he had landed Lieutenant Laird at Port Plata he left to carry out his orders. The climate of Port Plata was found by Lieutenant Laird to be decidedly unfavor- able for astronomical work. Rain was almost continuous while he was getting ready for work, and most of his star observations were made in the short intervals between showers. By taking advantage of every opportunity he succeeded in working on the nights of December 14, 15, 16, 19, and 20. No trouble from the weather was experi- enced at St. Nicolas Mole. Showers were frequent during some of the nights, but always passed over very quickly. While the Port Plata party was getting ready for work, Lieutenant Norris determined the latitude of St. Nicolas Mole. On the 20th of December Commander Rockwell arrived with the Yantic from the Cuban coast, and on the 2 ist Lieutenant Norris and party embarked for Santo Domingo City. This point was reached on the evening of December 24th, but it was several days before anything could be done in preparation for work. The week between Christmas and New Year's was a general holiday for the inhabitants, and it was next to impossible to find anyone willing to work. The Yantic was unable to get over the bar into the river, and her position outside in the open roadstead was very uncomfortable owing to the continuous heavy swell. As it was very necessary to make some repairs to her boilers which could only be done in smooth water, Commander Rockwell landed the party as soon as possible and then proceeded to Samana Bay, where there was a good harbor. Immediately after landing a call was made on the President of the Republic, who courteously offered every assistance. A site for the observatory was speedily selected near the foot of the old signal tower. As soon as workmen could be procured the pier was built and the instruments were mounted and adjusted and a wire was extended to the telegraph office about 200 yards distant. It had been found upon arrival at this point that the overland telegraph line to Port Plata did not belong to the same company that operated the cables, but to a separate organization. A call was made upon the resident director of this company, M. Gassend, and the object of the expedition explained to him, upon which he at once placed the line at the disposal of the party. As in the case of most land telegraph lines through a tropical country, the wire was frequently broken, or insulation destroyed, and interruptions to traffic were many. It was found that all messages between Santo Domingo and Port Plata were repeated at La Vega, a station about two-thirds of the distance from the former place. The operators were unanimously of the opinion that it would be impossible to work over the whole line, unless it happened to be in unusually good condition. As it was 14 TELECIEAPHIC DETERMINATION OF LONGITUDES not desirable to have the time signals repeated at La Veg-a if it could be avoided, it was decided to try the mirror galvanometer, it being delicate enough to be influenced by any current that could get through. This was also considered impracticable by the telegraph operators, but on trial it was found to work perfectly. No difficulty was experienced in exchanging signals, though the insulation of the line was so faulty that it was necessary to use from ten to fifteen LeClanch^ cells at each end. Bad weather at Port Plata delayed the work somewhat, but observations were made and signals exchanged on the nights of January 2,3,4, 5, and 6, which completed the measurement. While waiting for the Santo Domingo, party to get ready for work, Lieutenant Laird determined the latitude of Port Plata, and also made magnetic observations. As soon as the longitude observations were finished, Commander Rockwell proceeded in the Yantic to Port Plata, took Lieutenant Laird and party on board, and sailed for Curaqao, arriving on January 1 7.' The authorities at Curaqao took special pains to facilitate the work, and Lieuten- ant Laird was ready for observation on the 20th. No bad weather was encountered at either place, and the longitude measurement was completed in six consecutive nights, ending January 25. It had been intended that Lieutenant Laird should remain at CuraQao while Lieutenant Norris proceeded in the Yantic to La Gruayra, but as it was particularly desired by the Hydographic Office that magnetic observations should be made at the latter place, it was finally decided that Lieutenant Norris should remain at Santo Domingo. Lieutenant Laird was directed to proceed to La Guayra after finishing the magnetic and latitude work at Curasao. The cables were to be connected at Curasao, and the measurement made direct from Santo Domingo. This plan was carried out successfully. Lieutenant Laird reached La Guayra on the 2d of February, and was ready for work on the 6th. Some defect in the con- nections prevented the exchange of signals on that niglit; on the 7th, 8th, loth, and 1 1 th the work was satisfactory, and the measurement was completed. On the- 9th no signals were exchanged on account of the failure of the operator at Curasao to connect the cables together. As soon as he had completed the latitude and magnetic work at La Guayra, Lieutenant Laird embarked on the Yantic, which was in readiness Santo Domingo was reached on February 2 1 ; Lieutenant Norris and party were received on board, and the ship sailed the same evening for Key West. This port was reached two weeks later. By directions from the Navy Department, the instruments were shipped to Wash- ington by steamer, and the officers of the expedition proceeded to the same place by rail, arriving on March 1 1 . As has been said before, the members of the expedition, throughout the progress of their work, were the recipients of many acts of courtesy and kindness. To mention all to whom they are indebted for such acts would be to make a list of nearly everyone met. Special acknowledgment is due, however, to the president and officials of the Mexi- can and Central and South American cable companies in New York. These gentlemen, IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 15 knowing the difficulties to be encountered in the countries where their Hnes were situated, sent instructions to all their stations in Mexico and Central America to aid in the work in every possible way ; consequently, upon arrival, the party found in every case that all difficulties had been swept away as if by magic. The employes were never weary in assisting by all means in their power, and by their hearty co- operation many otherwise serious obstacles were easily surmounted. Special thanks are due to Mr. Cummings, general manager of the companies in the city of Mexico ; to Mr. Henry Millard, manager at Vera Cruz ; to Mr. F. W. Carpenter, at Coatzacoal- cos; to Mr. Atherton, at La Libertad, and to Mr. James Tiddy and Mr. Kelley, at San Juan del Sur. To Mr. F. Van Valkenburgh, isthmus superintendent of the lines, the debt of the expedition is still greater, as by his aid what promised to be the most difficult part of the journey — the crossing of the isthmus — was rendered comparatively easy. Special thanks are also due to the officials and employes of the French companies in the West Indies, who granted all necessary facilities, and cheerfully aided in all ways in their power. • Prominent in courtesy where all were courteous, may be men- tioned M. Raymond Wallut, administrateur of the Soci^tci Francjaise des Telegraphes Sous-Marins, and M. Gassend, the resident director in Santo Domingo of the Com- pagnie Teldgraphique des Antilles. At Santiago de Cuba, upon the breaking out of yellow fever, there was some temporary confusion in the French cable office, owing to the death of the manager, M. Pouyds; and the thanks of the expedition are due to Mr. Beall, of the English cable company, who generously offered his services as an operator, and contributed greatly to the success of the work, Special acknowledgment is to be made to His Excellency N. Van den Bran- denhof, governor of Cura9ao, who manifested much interest in the work, and materi- ally assisted in many ways. As was to be expected, the consular representatives of the United States were uniformly zealous in aiding the party to carry out its work. Special mention must be made, however, of Mr. Otto E. Reimer, consul at Santiago de Cuba, who, by his energy, zeal, and knowledge of the country and people, aided most materially in bring- ino- the work at his station to a successful termination. Thanks are also due to Mr. Albert Langner, consul at Tehuantepec; Mr. Emile Courtade, consul at La Libertad; Mr. Holmann, consul at San Juan del Sur; Mr. Thomas Simpson, consul at Port Plata; Mr. Juan A. Read, vice-consul at Santo Domingo ; Mr. L. B. Smith, consul at Curasao, and Mr. W. S. Bird, consul at La Guayra. The party at Santo Domingo is also indebted in many ways to Mr. Nathan Appleton, of Boston, who at that time was engaged in building a railroad from the city to the interior of the island. Last, but by no means least, the kindness with which the members of the party were received on board the Yantic by Commander Rockwell and his officers, and the valuable assistance which they cheerfully rendered on all occasions were fully appre- ciated at the time, and will always remain among the most pleasant recollections of the expedition. 16 TELEGEAPHIO DETERMINATION OF LONGITUDES DESCRIPTION OF THE STATIONS. VERA CRUZ. The site selected for the observatory at Vera Cruz was that used by Lieutenant- Commander Davis in 1883. (See Plate.) The pier, inside Fort Conception at the north end of the city, was found standing, but in bad repair. It was rebuilt and capped with a marble slab. The center of the pier was 39 feet S. and 20.5 feet E. (true) of the gun pivot in the northwest salient of the fort. From the center of the pier the vane of San Juan de Ulua light-house bore N. 63° 45' 20" E. (true), distant 3,488.2 feet. Connection was «iade with the telegraph office by means of an iron wire stretched on insulators from the parapet of the fort over the roof of the railway station and thence to the office. The pier was left standing, but can not be considered as a permanent mark. COATZACOALCOS. The observatory was placed in a street near the center of the town, about 500 yards from the landing place on the river. (See Plate.) The pier was built of bricks and Portland cement, the latter brought from Vera Cruz. The light-house was in plain sight from the observatory. The magnetic observatory was placed about 50 yards north of the transit pier and in the same meridian. A telegraph line extended to the cable office about a third of a mile distant From the center of the transit pier the center of the light-house bore N. 15° 58' E. (true), distant 1,013.8 feet. At the conclusion of the work the pier was left standing, and it is hoped that it may remain as a permanent mark. SALINA CRUZ. • The transit pier was built of bricks and mortar of native manufacture, by a native bricklayer. It was situated in the northeast corner of the grounds belonging to the cable company, at a distance of about 50 yards from the cable house. (See Plate.) To the nortli was a low range of hills, and to the south, about 200 yards distant, was the Pacific Ocean. The magnetic observatory was placed in the meridian of the transit instrument, about 30 yards to the south. From the center of the transit pier the observation point on Morro Salina bore S. 65° 10' W. (true), distant 7,395.1 feet. The transit pier was left standing and is not likely to be disturbed. LA LIBEETAD. The observatory was located near the center of the small yard, in front of the telegraph office, between that building and the beach. (See Plate.) Before finally deciding upon this site, experiments were made to ascertain whether or not the heavy surf on the beach, only ,20 or 30 yards away, would produce sufficient vibration of the IN MEXICO, OENTBAL AMERICA, THE WEST INDIES, ETC. 17 ground to affect the instruments. It was found that there was no perceptible effect, and the pier was built and the observatory and instruments set up. A double wire was extended to the telegraph office only a few yards distant. A careful reference was made by triangulation to the site of the old pier used in 1 884 by Lieutenant Laird, with the following result. From the center of the new pier the old pier bore N. 9° 13' W. (true), distant 279.8 feet. This pier was left standing and is not likely to be removed SAN JUAN DEL SUE. The telegraph station at this point was shut in by trees to the north and by hills to the south. A convenient point was found in the yard, however, where by cutting down a tree a good view of the northern sky was obtained. The pier was built of brick and cement. A strong north wind was blowing most of the time, and it was necessarj' to secure the observatory tent by additional guys on the weather side. The old observation spot marked on the chart could not be exactly identified, so reference was made by triangulation to the signal station and light-house on a hill south of the harbor. From the center of the transit pier the signal station bore S. 44° 51' W. (true), distant 2,991.4 feet. The pier was left standing and will probably remain as a permanent mark. (See Plate.) SANTIAGO DE CUBA, The station at Santiago de Cuba was in the rear of the Blanca Battery, about half a mile to the southward of the city. (See Plate.) This site had been used by Lieutenant-Commander Green, U. S. Navy, in 1875. The pier used by him had been removed, but near the same spot another had been erected by Spanish officers. This latter was used. Through the courtesy of the manager of the West Indian and Panama Cable Company at this station the line extending from the cable hut to their office was used for connecting with the French telegraph office. A loop was run from the observing tent to the cable hut, about 125 yards distant, and by means of an arrangement of switches the telegraph instruments in the tent could be connected up at pleasure. Every evening the line was connected with the cable of the Socidtd Fran9aise des T^ldgraphes Sous-Marins at the office and the signals exchanged from the observing tent. The sheathing of the West Indian and Panama cable was used as an earth. From the center of the pier the southeast corner of the battery inclosure bore N. 45° 44' W. (true), distant 105. i feet. The pier was left standing, and, as it is in the grounds connected with the fort, will probably remain as a permanent mark. ST. NICOLAS MOLE. The observatory was located in the middle of one of the streets near where it terminated on the beach on the north side of the village. The outlook to the north 21124— No. 97 2 18 TELEGRAPHIC DETERMINATION OF LONGITUDES was over the bay. The pier was built of bricks and cement. A double wire was extended to the telegraph office, about 40 feet distant. (See Plate.) By triangalation the flagstaff of Fort St. Greorge was found to bear from the pier N. 89° 29' W. (true), distant 1,117.5 feet. This pier was left standing and will probably remain for some time. Although it is in the middle of a street there is no traffic of any kind to interfere with it. POET PLATA. The observatory was placed on the promontory to the north of the city. (See Plate.) The pier was built of brick and cement. Connection was made with the telegraph office, about 320 yards distant, by means of an insulated wire stretched from house to house. From the center of the pier, the light-house near the signal station bore N. ^^° 28' 15" W. (true), distant 565.4 feet, and the cross of the Catholic church bore S. 1° 28' 15" E, (true). The pier was left standing, but can not be considered as a permanent mark. SANTO DOMINGO CITY. One of the most notable features in this place is the large square signal tower, on the right bank of the Ozama River near its mouth. It was built by the first Spanish settlers during the time of Columbus. A room is shown in the building which is said to have been the place of confinement of Columbus before he was sent as a prisoner to Spain. At the foot of the tower is a large parade ground, surrounded on the landward sides by extensive barracks now in a more or less ruinous state. On this parade ground a short distance south and west of the tower was located the transit pier. (See Plate.) It was an excellent situation, having a clear north and south view, and very quiet and free from interruption. The pier was built of bricks and cement. A wire was extended along the barrack walls to the telegraph office. The reference point given on the Hydrographic Office Chart is the iron light-house on the south side of the city, about a quarter of a mile distant from the mouth of the river. The bearing and distance of this light- house from the signal tower were obtained from a civil engineer who had made a careful survey of the city. The bearing and distance of the tower from the transit pier were measured directly with the following results : From the transit pier the southwest angle of the tower bore N. 50° 48' E. (true), distant 219.4 feet. From the pier the Hght-house bore S. 43° 2' W. (true), distant 1,583.2 feet. The pier was left standing, and will probably not be removed. CDKAgAO. The site selected for the observatory at CuraQao was in the open space in front of the governor's mansion. (See Plate.) The center of the pier was 55 feet 3^ inches W. (true) from the inner western angle of the entrance gate to the inclosure, and the IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 19 distance in the meridian liae north to the edge of the sea jvall was 21 feet, 7^ inches. The vane on the RifF Fort hght-house bore from the center of the pier S. 80° 45' 30" W. (true), distant 1,148.7 feet. Connection was made with the telegraph office by means of an insulated wire. At the conclusion of the work at Curasao the pier was removed. LA GUAYEA. The observatory was situated near the northeast corner of the vacant lot to the eastward and adjoining the market. The railroad to Macuto passed between the obser- vation spot and the sea wall. (See Plate.) No direct measurement to the light-house in present use could be made, so the position of the observation spot was referred to the light-house situated about 100 yards to the eastward of the shore end of the breakwater. The center of the pier was 119 feet i inch S. (true) from the outer face of the sea wall, and the above-described light-house bore N. 72° 17' W. (true), distant 1,212.8 feet. The pier was built of the usual material, and connection made with the telegraph office as at the other stations. • Upon the conclusion of the work all traces of the pier were removed. DESCRIPTION OF THE INSTRUMENTS. MERIDIAN INSTRUMENTS. At all the stations occupied by the expedition, two of the meridian instruments made by Stackpole, of New York, for the Transit of Venus Commission in 1874 were used. These instruments have a focal length of 30 inches, and an aperture of 2i inches. The eyepiece is at the end of the axis, so that the observer always retains the same position. They possess the advantage of great stability; when once adjusted in the meridian there is no necessity of readjusting in azimuth, under the ordinary conditions. The zenith telescope level and micrometer attached to the instrument enabled it to be used for the latitude determinations. These instruments were originally fitted with reticules of spider lines, but on a former expedition the danger of injury in transportation was so clearly shown that these were replaced by ruled glass diaphragms, the lines of which were arranged in groups as follows : One, three, seven, three, one. The middle group of seven was the only one used in observing transits for time. A spare transit, a combined transit instrument and zenith telescope, designed by Mr. J. A. Rogers in 1873 for the U. S. Hydrographic Office, was taken with the advance party of the expedition to be used in case of accidents. CHRONOMETERS. The time pieces used by the expedition were four break-circuit sidereal chronom- eters, and two break-circuit mean time chronometers, made by Negus. 20 TELEGEAPHIC DETERMINATION OF LONGITUDES The break-circuit sidereal chronometers are the same that have been used on all the exi)editions sent out by the Bureau of Navigation since 1874. They have given the greatest satisfaction, and the rates under the trying circumstances of marked change in temperature and condition have been generally regular. CHEONOGEAPHS. Two cylinder chronographs, manufactured by Fauth & Co., were used. These instruments are easily regulated, of hght weight, can be wound without being stopped, and by pushing a button the speed of the cylinder can be doubled. INK WEITEES. Each party carried a Siemens polarized ink writer. These instruments were originally purchased for use on the Brazilian land lines in 1879. Since then they have been carried on every expedition sent out by the Hydrographic Office. They have been found most useful, not only as a telegraph instrument, but also have been made to serve as a chronograph and used as a polarized relay on both land lines and cables where the feeble current demanded an extremely delicate relay. BATTEEIES. Each party carried twenty-four gravity cells made of vulcanite packed in boxes containing twelve each, together with a supply of coppers, zincs, and copper sulphate. PORTABLE OBSEKVATOEIES. The wooden observatories that had been in use on all previous expeditions were used at the stations of Vera Cruz and Coatzacoalcos. These huts were made to put together in sections, each side and top being composed of two sections ; the sides were bound together with cross pieces held in place by iron knees The sections of these observatories were too bulky to be packed over the mountains, so they were shipped to the United States after the conclusion of the work at the above-named stations. At the other stations of the Mexico-Central American expedition, two observing tents, designed by Lieut. J. A. Norris, were used. They proved so satisfactory that the wooden observatories were discarded and the tents alone taken on the West Indian expedition. The parts of the frame of these tents, together with the connections, were inter- changable ; the whole set on a solid foundation of sills floored over. A slit i foot wide, commencing 3 feet from the floor extended across the roof from side to side, 4 feet from one of the ends. This arrangement gave sufficient sweep for the transit instrument in both azimuth and altitude, and allowed ample space at the other end of the tent for the tables, chronometers, chronograph, and telegraph instruments. Three tables, capable of being taken apart for packing, were furnished with each tent. All metal fittings were made of composition, in order that the tents could be used to cover the magnetic instruments. The severe strain these tents have been put to whilst in service shows that they are admirably adapted for the work. IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 21 Each party was supplied with a wall tent to be used as a habitation when neces- sary. One of the wall tents, worn out during the first season's work, was replaced through the courtesy of the War Department by a regulation hospital tent. TRANSIT PIEES. A pier of brick and cement, 24 inches by 22 inches and 36 inches high, was built at each station as a foundation for the transit instrument. On this and previous expeditions it was found necessary at some of the stations for the officers to build the pier themselves. To facilitate matters, bricklayer's tools, a marble slab, and, when there was a probability of not being able to procure material, bricks and cement were carried as part of the outfit. MISCELLANEOUS ARTICLES. Besides the articles above enumerated, each party carried an aneroid barometer, a thermometer, a plug switch-board, several relays of different resistance, detector galvanometers, a break-circuit chronograph key, a supply of insulated copper wire, screw posts, binders, insulators, a theodolite, a surveyor's chain, and a supply box containing tools, lanterns, oil cans, etc. The party in charge of Lieutenant Norris carried a complete photographic outfit. The party in charge of Lieutenant Laird carried the latest pattern of Kew unifilar magnetometer and a Barrow dip circle. INSTRUMENTAL CONSTANTS. The values of the flexure and inequality of pivots and of the revolutions of the micrometer screws of transit instruments Nos. 1503 and 1504 were obtained from Prof. William Harkness, U. S. Navy, of the Transit of Venus Commission. He also furnished the original recorded values of the divisions of the levels, but it was found that some of the scales had been interchanged, while others had been broken and replaced by new ones, so that it was necessary to redetermine these values. The striding level tube of No. 1504 used by Lieutenant Laii'd caused a great deal of trouble by leakage. It was refilled several times, but could not be sealed tight enough to prevent the escape of the liquid. In consequence of this, Lieutenant Laird was several times compelled to substitute the tube of the zenith telescope level for the defective one, sometimes using it with its own scale and sometimes with the other. From this cause several different values of the level divisions enter into his work. The values of all the levels were determined by observations of a terrestrial object, some made in the field during the progress of the work and others after returning to Washington. These were verified by measurements made with the mural circle at the Naval Observatory at Washington. The values adopted are as follows : LEVELS, TRANSIT NO. 1503. s. " Striding level i division = 0.076 = 1.14 Zenith telescope level i division = 1.53 22 TELEGRAPHIC DETERMINATION OP LONGITUDES LEVELS, TRANSIT NO. 1504. Striding level with proper scale i division — 0.091 r= 1.36 Zenith telescope level with proper scale i division rz 1.35 Zenith telescope tube with striding scale ^ . i division = 0.084 — ^ 26 Striding tube with zenith telescope scale i division :zi 1. 14 FLEXURE AND INEQUALITY OF PIVOTS. No. 1 503. Flexure (./) + inequality of pivots, circle East z= + 0-3 ' 5 No. 1 504. Flexure (/) + inequality of pivots, circle East . - = + 0.283 MICROMETER SCREWS. No. 1 503 - I revolution ::; 68.89 No. 1 504 I revolution == 69.36 EQUATORIAL THREAD INTERVALS. In the following table the equatorial intervals from the mean of the threads are given. The threads are numbered in the order in which they would be crossed by an equatorial star, in the position of the instrument circle East. These intervals were determined by many observations of the transits of circumpolar stars. They were determined separately for each season's work, but as will be seen differ only slightly : Threads. Transit No. 1503. Transit No. 1504. First season. Second season. First season. Second season. I -I3-'8S4 — 9. 231 — 4. 580 + 0.008 + 4- 632 + 9- 238 + 13-832 s. —13-834 — 9.251 — 4- 636 — 0. 001 + 4-635 + 9- 250 + 13- 839 8. -12.195 — 8.064 — 4- 058 + 0.032 + 4. 066 + 8.091 -)-I2. 164 8. —12. 144 — 8.054 — 4. 024 + 0-034 + 4-007 + 8.004 + 12.167 II III IV V VI VII METHODS OF OBSERVATION. OBSERVATIONS FOR TIME. Upon arrival at a station the first care was to select a suitable site for the observa- tory. It was necessary that there should be a clear view of the heavens in the line of the meridian from the zenith to as near the horizon as possible. It was desirable that the situation should be secluded to avoid annoyance from idle and curious inhab- itants, and to obviate the necessity of a long telegraph wire it was well to get as near as possible to the telegraph office. A site with these advantages being found, permis- sion to use it was obtained from the proper authorities. A meridian line was then laid m MEXICO, CENTRAL AMEEICA, THE WEST INDIES, ETC. 23 out by compass and the transit pier was built. As soon as this was completed the observatory was erected over it and the instruments were mounted, batteries were set up, and the chronometer and chronograph connections were made. The level and collimation of the transit instrument were adjusted and a wire was extended to the telegraph office. On the first clear evening the transit was set in the meridian by repeated observations of zenith and circumpolar stars, and the chronometer correction was obtained. All preparations being complete at each end of the line, the method of work was generally as follows : If the weather was clear, and likely to remain so, the observer would begin work at any convenient time after dark, usually from 7 to 8 p. m. If it was likely to be cloudy, observations were begun as soon after sunset as possible. Five or six time stars and two or three circumpolars were observed, the striding level being frequently applied and read. Then the instrument was reversed in the Y's and about the same number of stars observed in the new position. If the nights were clear this could be done within less than two hours, but when the weather was cloudy the observations would frequently extend over six or eight hours. From the terms of the agreement with the telegraph companies the lines could be used for the exchange of time signals only after their day's work was finished. On the lines in Mexico and Central America this was generally quite late at night, usually between 11 p. m. and midnight, except on Sunday, when the work was finished earlier. On the lines in the West Indies the work was generally over by 8 p. m. On the line between Vera Cruz and Coatzacoalcos and thence to Salina Cruz the instruments used were the ordinary Morse relay and sounder, and between these places the signals were exchanged automatically. Connections were made at both ends of the line in such a way that the chronometer at one observatory would register its second beats upon the chronograph at the other, which chronograph was at the same time registering the beats of its own chronometer. This was done for a certain number of minutes and the connections were then changed by means of switches, so that the operations were reversed. For this purpose the telegraph instruments and connections were in the respective observatories, and the wire leading therefrom was simply connected at the office with the main line. One of the telegraph operators would do this and then go to the observatory to do the necessary talking. Where mirror signals were used the arrangement was diff"erent. The mirror was set up in the telegraph office and connected to the key and to the main line in the regular way. This key was in its main features like the ordinary cable key with two levers, and could be used for the regular telegraphic work. It had, however, an extra contact point which was connected with the wire leading to the observatory in such a -way that by pressing one of the levers of the key an impulse would be sent over the cable, and at the same instant a mark would be made on the chronograph in the observatory, thus recording the exact time at which the impulse was sent. The observer at the other end of the line would see the result of this impulse in the form of a movement of the light reflected from his mirror, and would record the time of his perceiving it by pressing a key connected with the chronograph circuit in his observatory. 24 TELEGRAPEIO DETERMINATION OF LONGITUDES The exact procedure adopted was for the first observer to press his cable key at intervals of two or three seconds for fifteen times, then a pause of eight or ten seconds and another set of fifteen pressures, and so on until seventy-five signals had been sent in groups of fifteen. The other observer recorded all this on his chronograph, and then in his turn sent seventy-five signals in the same way. The next day each observer sent to the other by telegraph the even minute which preceded the first signal that he sent, and also the one that followed the last signal. It was found that the agreement between the signals received by an observer was generally quite close, not often differing from the mean by as much as a tenth of a second. A few discordant ones would usually be found, generally at the beginning of the groups of fifteen; these were rejected, and the final result would be from the consideration of about seventy signals sent each way. For a more full description of the methods of exchanging signals the reader is referred to the report of the longitude expedition of 1883-84, mentioned in the foot- note on page 5. LATITUDE OBSERVATIONS. For latitude work an observing list was prepared showing the pairs of stars available, in the order of their right ascension, giving their zenith distance and the setting of the instrument, and the approximate time of culmination. Stars were selected which were within 25° of the zenith, but those used were generally much nearer than that. The stars of a pair did not differ in zenith distance more than twenty minutes of arc, and were from two to fifteen minutes apart in right ascension. On clear nights latitude observations were generally made after the time work had been finished. When this was impracticable a few nights were employed after the conclusion of the longitude work. The method of observation was to set the instrument at the mean zenith distance of a pair of stars just before the first one entered the field; the zenith telescope level was adjusted so that the bubble was brought to the middle of the tube. When the star appeared it was followed by the micrometer thread and bisected as it crossed the middle transit thread. The micrometer and level were then read and recorded and the instrument reversed The second star was observed in the same manner, using the same micrometer thread. The chronometer time of each transit was also recorded. This constituted one observation for latitude, and as many were made at each station as circumstances would permit. TRIANGULATION. From the nature of the conditions governing the selection of sites for the observ- ing stations, they were frequently placed in secluded localities, and as the piers could not generally be considered as permanent, it was necessary to reduce the latitude and longitude obtained by observation to some prominent and well-established landmark. At most stations the point chosen was that fixed on the Hydrographic Office Chart of the place, or that given in the Hst of positions published by the Hydrographic Office. In making these measurements the bearing was usually obtained by reference to a meridian mark established with the transit, and the distance was either measured directly, or else the ordinary method of measuring a base line and angling from its IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 25 ends with a theodolite was employed. The bearing and distance at each station of the chosen landmark from the center of the transit pier are given in the description of the stations. PERSONAL EQUATION. As in most of the longitude measurements made under the direction of the Bureau of Navigation, no correction for personal equation has been introduced in the following computations. The observers had no method of obtaining a value for this changeable quantity while in the field, and it was, therefore, considered better to omit it altogether rather than put in an arbitrary quantity obtained from observations made before the starting of the expedition or after its return. If circumstances had permitted the exchange of stations by the observers in the middle of each measurement, it would have been the best way of eliminating error from this cause, but it was manifestly impossible to do so, from lack of time and from other considerations. As far as possible the observers were located alternately east and west of each other, thus prob- ably diminishing, if not eliminating, the error at every second station. The measure- ments made between Santiago de Cuba and Curasao, as also between Santiago de Cuba and La Guayra, were four in number, Lieutenant Norris being alternately east and west of Lieutenant Laird; consequently the longitudes of Cura9ao and La Guayra, as derived from Santiago de Cuba, may be considered substantially free from the effects of personal error. In the measurement between Vera Cruz and La Libertad, Lieutenant Norris was first east, then west, and then east again of Lieutenant Laird; hence, the longitude of La Libertad, as derived from Vera Cruz, is liable to correction for the difference of personal equation between Norris east and Laird west. San Juan del Sur is in the same category with La Libertad, the longitude being derived by the same number of measurements from Vera Cruz. METHODS OF REDUCTION. REDUCTIONS OF TIME OBSERVATIONS. The reduction of all the time observations was made by Lieutenants Norris and Laird and Ensign Garrett. Lieutenant Norris reduced xill his own observations; Lieutenant Laird reduced the observations made by him during the work of the first season, while Ensign Garrett reduced those made by Lieutenant Laird during the last season. The chronograph sheets were read twice and compared with the record. To the observed time of transit of each star reduced to the mean of the threads were applied the flexure of the axis and inequality of pivots, level, azimuth, collimation and diurnal aberration, and hourly rate The difference between the reduced meridian passage of each star and its right ascension gave a value for 'the clock correction at the epoch to which all the observations of that night were reduced. 26 TELEGEAPHIO DETERMINATION OF LONGITUDES Each star then furnished an equation of condition for the final reduction to de- termine the corrections to be applied to the assumed values of the azimuth and col- limation constants and the mean clock correction. These equations were solved by the method of least squares, and with the corrected values of the collimation and azimuth constants, a new clock correction for each star was obtained. The mean of these corrections, rejecting circumpolar stars, was the finally accepted clock correction. The weight unity was assigned to all time stars and the circumpolars were weighted for declination. The hourly rate was obtained graphically by the construction of a curve. For this purpose all the time observations made at each station were reduced and the differ- ences between the clock corrections on the several nights deduced from the time stars alone, gave the data for determining the known points of the curve. The middle time of the signals sent and received at each station was the epoch of comparison; and the middle time of the observed times of transit of clock stars was the epoch of reduction on the same night. The clock correction was reduced from the epoch of reduction to the epoch of comparison by applying the product of the hourly rate, taken from the curve, multiplied by the elapsed time expressed in hours. EEDUCTION OP LATITUDE OBSERVATIONS. The reduction of the latitude observations was made by Ensigns Wood and Wilson; Ensign Wood reducing those made during the first season's work, and Ensign Wilson the remainder. The stars used were originally selected from the British Association Catalogue. In reducing the observations the declinations were taken from the Nautical Almanac, the Berliner Jahrbuch, the Catalogues of Newcomb, Safi'ord, the Coast Survey, and the various Greenwich lists. The following notation was adopted: Let q> z=. the latitude of the station ; <5„ and d, =z the apparent declinations of the northern and southern stars ; Tauri . 7 4 9 30-421 +0.315 — 0. 046 — 0. 044 +0. 214 — 0. oig 30.841 3 21 9.072 21.771 — 0. 121 > Camelop. 11. E. 7 4 27 0.457 +0. 584 — 0. 14S +0. 697 +0. 648 — 0. 001 2.237 3 38 40.076 — 48[22. 161] X Tauri W. 7 4 42 54- 161 — 0. 321 +0. 086 —0. 032 -0. 257 +0. 016 53-653 3 54 31-829 — 48 21. 824 — 0. 068 V Tauri .... 7 4 45 37-453 — 0. 309 +0.091 — 0. 065 — 0. 252 +0.018 36- 936 3 57 15- 119 21.817 -0.075 0' Eridani 7 4 54 49. 297 -0. 287 +0. log — 0. 129 — 0. 253 +0. 028 48. 765 4 6 26. 944 21.821 -0.071 y Tauri . . 7 5 ' S°-944 — 0. 326 +0. 143 —0.015 — 0. 260 +0. 035 50. 521 4 13 28,681 2 I . 840 — 0. 052 6 Tauri 7 5 4 54- 360 — 0. 330 +0. 151 — 0. 005 — 0. 263 +0. 038 53-951 4 16 32.095 21.856 —0. 036 a Tauri 7 5 17 55.621 -0. 328 + 0.175 — 0. 010 —0. 262 +0.052 55- 248 4 29 33-219 22.029 +0. 137 Groom. 848 . . 7 5 28 18.807 —0. 685 +0.379 + 1.024 —I. 019 +0.056 18.562 4 33 56-838 [21.724] T Tauri . . 7 5 23 57-481 -0. 341 +0. 190 +0.026 — 0. 272 +0.058 57.142 4 35 35-138 22. 004 ■\-0. 112 ^ Camelop. 7 5 31 24.357 -0. 843 +0. 492 +0. 550 — u. 621 +0. 066 24. 001 4 43 2. 102 [21.899] i Tauri . . . w. 7 5 33 15-330 -0. 332 +0. 196 +0. 003 — 0. 265 +0. 068 15.000 4 44 53- 036 — 48 21. 964 + 0.072 Assuming a' ^= — o. 437 + da' circle E. a" = — o. 327 + da" " W. c ^ + o. 259 + dc " E. AT = -oii48"'2i». 873+fl'/. NORMAL EQUATIONS. -o.3i3+i-979^«' — 0.016 +2. 554a'a"+ 2.liydc~ o. l^sdt \ + 0. 662 — o. 705a'«' + 2. iiy da" -\- 22. 68<)dc — o. 840 rt'^ ] + 0. 130 + 0. 5lon'a'— o. iSida" ~ o. 840fl'-i- 757 +0. 803 -0. 497 —1.969 + 1.805 +0. 025 33- 924 2 SI 22.359 [11-565] u. Ceti 3 44 39- 170 +0. 306 ~o. 202 -f 0. 108 +0. 346 +0.031 39- 759 2 56 28. 279 11.480 +0.058 48 Cephei, H. . . . 3 54 28. 164 +0- 735 -0. 541 —1.688 + 1-573 +0. 044 28. 287 3 6 16.516 [II. 771] f Arietis. . . . 3 56 41. 966 +0- 336 -0- 253 — 0. 019 +0. 368 +0. 047 42. 445 3 8 31.012 11-433 +0. on Tauri 4 7 1.067 +0.314 —0. 260 -|-o. 072 +o. 349 +0.061 1.603 3 18 50. 176 11.427 +0. 005 f Tanri . . 4 9 19-923 +0.315 —0. 266 -|-o. 067 +0. 349 +0. 064 20.452 3 21 9.008 11.444 +0. 022 Groom. 716 . . E. 4 20 42. 986 +0.491 -0. 455 —0. 664 +0- 756 +0. 079 43- 193 3 32 32.042 — 48[ii. 151] Assuming a' = + o. 303 + da' circle W, a" = + o. 446 + da" '• E. c = + o. 364 + dc " E. AT = — 0l'48'niI».422+(/,^. NORMAL EQUATIONS. 0= — o. 027 + 3. 5i9$i dt\ + 0. i52;-j-fl''^ " E. ] + 1.723 — i.297(/a'' + 4. i67a'a"-)-27.592a'f+ -^.Tp^dtX — o'l 48™ 9". 339 + ^^ L +0.201 + 0.574^/3' — o. 85 1 a'a" + 3.304(/c-+ 15. 677^'^ J a' ^-\- 0^.058 (circle east) ; a" = + o».o75 (circle west) ; c = o».095 ( + with circle east). Chronometer No. 1295 at 3'' 22™.5 chron. time, o^ 48" 9'.3i6 j-; o=.oi6fast, losing 08.094 per hour. whence da' = — 050 da" = — u 052 dc = — 057 dt =^ — 002 IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 35 Transits of Stan observed at Coatzacoulcos, Me.xieo, by Lieut. J. A. Norris, U. S. Navy, wit/i transit No. ijoj, to determine the correction of sidereal chronometer Negus No. I2gj. Date. Name of star. 2 .a 6 Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and coUi- mation. Rate. Seconds of corr. transit. R.A. Chronometer corrections. V. 1SS9. Jan. 10 V Pisciuni .... w. 7 //. m. s. 2 23 46. 130 — 0. 308 s. —0. 025 +0. 028 J. — 0. 184 s. — 0. 067 s. 45-574 h. m. s. I 35 38-478 h. m. s. — 48 7.096 s, +0. 038 Pisciuni 7 2 27 38- 743 —0.314 — 0. 030 -|-o. 020 — 0. 185 —0.061 38 173 I 39 31- 149 7.024 — 0. 034 E Cassiop, . . 7 2 34 32. 707 — 0. 492 -0. 053 — 0. 191 — 0. 405 -0.051 3' 515 I 46 24. 236 [7. 279] ,i Arietis . . . 7 2 36 37-509 — o- 335 — 0. 038 — 0. 005 -0- 195 — 0. 048 36 888 I 48 29.771 7. 117 +0- 059 50 Cassiop. . . 7 2 42 5.921 -0. 598 — 0. 076 -0.316 -0. 589 -0. 039 4 303 I 53 57-382 [6.921] U Arietis 7 2 49 2. 004 — 0- 341 — 0. 048 — 0. 01 1 — 0. 199 —0. 029 I 376 2 54. 333 7.043 — 0.015 Ceti . ... 7 2 55 >3-949 —0.314 — 0. 049 -|-o. 021 — 0. 185 — 0. 019 3 403 276. 388 7.015 — 0. 043 ti Arietis . ... 7 304. 143 — 0. 334 — 0. 056 —0. 003 — 0. 194 — 0. 012 3 544 2 II 56.488 7.056 —0. 002 I Cassiop. . . . w. 7 3 8 3-357 -0. 530 -0. 097 — 0. 234 — 0. 466 0. 000 2 030 2 19 55-085 — 48 [6. 945] • • 36 H. Cassiop. . . E. ^ 3 IS 36-493 ^-o. 607 — 0. 403 — 0. 470 +0.471 +0. 012 36 710 2 27 29. 603 — 48 [7. 107] V Arietis . . . 7 3 20 37-117 +0. 338 — 0. 238 — 0. 01 1 H-o. 154 +0. 019 37 379 2 32 30-320 7.059 +0. 001 Br. 366 . . . 7 3 23 23. 643 +0. 534 — 0. 390 — 0. 346 +0.371 +0. 023 23 835 2 35 16.947 [6. 888] 35 Arietis . . . 7 3 25 2. 643 +0- 350 — u, 260 —0.031 +0. 161 -|-o. 026 2 889 2 36 55-848 7.041 — 0. 017 H- Ceti 7 3 27 2.866 +0.316 ^0. 240 +0. 026 +0. 145 +0.029 3 142 2 38 55- 987 7- 15s +0. 097 41 Arietis . . . 7 3 31 33-401 +0. 349 — 0. 274 — 0. 030 -|-o. 160 +0. 036 ZZ 642 2 43 26. 594 7.048 —0. 010 47 Cephei, H. 7 3 39 29.214 +0- 803 — 0. 662 — 0. 804 +0. 748 +0. 048 29 347 2 51 22. 171 [7- 176] a Ceti . 7 3 44 35-011 +0. 306 — 0. 255 +0. 044 +0. 143 +0.056 35 304 2 56 28. 256 7.048 — 0. 010 (S Arietis ... . E. 7 3 53 23-306 +0. 344 — 0. 2S2 — 004 +0. 152 +0. 069 23 585 3 5 16.587 — 48 6. 998 — 0. 060 Assuming ii' \-o. i2g-\- da' circle W. a" = + o. 191 +53m58».ii9 -f-aV. (^ -f-o. 026-|- i. 553a'a' — o.^i6da''-\- i. 2^0 dc -\- i^. yoi dt j dt = -|- o. 008 a'^-f- o',076 (circle east); a" = — o».oi7 (circle west); f = 0^.404 ( -f- with circle east). Chronometer No. 1295 at 9'' 48">.8 cliron. time,o'' 53"' 58'. 103 -|- o''.oi7 fast, losing o». 188 per hour. Feb. 10 (! Orionis . 54". 257 + dt. -- — o. 482 + o. 069 NORMAL EQUATIONS. 4. 298 da' -4. ^idda' O. 120(/ 53" 54". 265 + o'.oi5 fast, losing o''.i78 per hour. IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 37 Transits of stars olisci-'t-d at Salina Cr, jViwicfl, by Lieut. J. A. Norris, U. S. I\lmiy,vfith transit No. 1503, to determine the correction of sidereal chronometer Negits No. i2g^. Date. Name of Star. Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. s. +0. 435 Rate. Seconds of corr. transit. R. A. Chronometer correction. V. 1SS9. Feb. 1 1 —--, Ononis . . E. 7 //. ni. s. 5 42 17-570 s. +0. 306 s. ~o. 070 — 0. 006 s. — 0. 170 18.065 h. in. s. 4 48 28. 067 h. m. s. -0 53 49- 998 s. —0. 124 10 C.imelop. . . 7 5 47 21.779 -f 0. 456 — 0. 103 +0. 034 +0-877 — 0. 156 22.887 4 53 32- 874 [50.013] Tauri 7 5 50 17.061 +0. 337 -0. 075 +0. 002 +0. 467 — 0. 148 17.644 4 56 27. 545 50. 099 — 0. 023 " Ononis . . 7 5 52 2.996 +0. 326 — 0. 072 0. 000 +0.451 — 0. 142 3-559 4 58 13-478 50.081 — 0. 041 ,.3 Orionis 7 631- 739 -|- 0. 290 —0. 066 — 0. 010 +0. 4.-10 — 0. 112 2.281 5 9 12.238 50. 043 — 0. 079 ' Orionis . . . 7 6 22 33. 234 +0.317 — 0. 092 —0. 003 +0. 441 -0.057 ZZ- 840 5 28 43.654 50. 186 -|-o. 064 2 5 19 5 24 5 28 5 29 5 31 5 40 5 42 5 49 5 51 5 59 6 I 6 6 6 8 17 569 12 224 12 079 10 637 54 645 43 642 55 949 713 57 946 29 688 9 900 21 197 6 714 41 686 37 707 10 917 -o 53[46. 46. 46. 46. [45- 46. 46. -o S3 46- -u 53 46. 46. 46. 46. 46. [46. [46. -o 53 46. 735] 216 387 332 960] 218 165 127 231 226 170 304 294 238] 361] 220 o. 025 -|-o. 146 +0.091 — o. 023 o. 076 — o. 114 o. 010 — o. 015 — o. 071 -f-o. 063 +0.053 Assuming a' AT — 1 . 95 1 (/<: + o. 644 dt ~\ whence da -{- 2. 6yg da" -\- i.S33nV-f- o. 141 dt \ ^. NORMAL EQUATIONS. :-f-o. 8n +a'3'' circleE. ( o = + o. 222 -\- 3. 455 da' -. + o.64S + da" •• W. i — o.oio = 4-0.419 + 0^ " E. 1 — o 216— l.9Si(/a' + i.533'/'''''+i9-947<^^— 0.269^^ ,_0li53in46».248+/*. I — 0.037 -I- 0.644 (/,<'+ O. 141 r/u"- O. 269()'f-f- I2.6oin'/' a' = + o>.748 (circle east); a" = + o. 646 (circle west); r = o. 424 ( -f- with circle east). Chronometer No. i29Sat6ti 3ora.6 chron. time, oH 53™ 46=.24i -|-o».oiS fast, losing o'.isg per hour. s. = — o. 063 da" = -f-o. 001 dc = -f- o. 005 dt ^ -f- o. 006 38 TELEGRAPHIC DETERMINATION OP LONGITUDES Transits of stars obserued af Salina Cruz, Mexico, by Lieut. J. A. Norris, U. S. Navy, with transit No. 1S03, to determine the correction of sidereal chronometer Negus No. I2C)^. Date. Name of star. u u Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate. s. — 0. 100 Seconds of corr. transit. R.A. Chronometer correction. V. 1889. Feb. 13 ( Tauri . . . E. Ji. m. s. s 50 9-530 s. +0. 337 s. — 0. 073 J. — 0. 052 s. +0. 395 s. 10. 037 h, m. s. 4 56 27.514 /;. m. s. — 53 42-523 s. +0. 029 II Orionis . . . 5 51 55-426 +0. 326 — 0. 070 +0, 009 +0.381 -0. 095 55-977 4 58 13-449 42. 528 +0. 034 19 II. Camelop. . . S 57 59- 943 +0.-758 — 0. 164 —2. 482 + 1-947 — 0. 080 59. 922 5 4 17-473 [42. 449] . . . /3 Orionis . . . . 6 2 53. 900 4-0. 290 — 0. 063 +0. 221 +0. 372 — 0. 067 54- 653 5 9 12. 209 42.444 —0. 050 r Orionis . . . . 6 5 54-716 -|-o. 292 — 0. 063 4-0. 209 +0. 371 -0.059 55.466 5 12 12. 965 42. 501 +0. 007 17 Camelop. . . . 6 13 23.743 +0.475 — 0. 103 -0. 845 +0.810 — u. 039 24. 041 5 19 41-556 [42.485] . . . & Orionis . . 6 20 1 . 949 +0. 302 — 0. 065 +0. ISO +0. 368 — 0. 022 2.682 5 26 20. 212 42. 470 —0. 024 ' 53™ 38^.595 -j- o'.oia fast, losing 0M69 per hour. whence da' ^= — o. 020 da't =z + o. 004 dc = — o. 03 2 dt = — o. 003 IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 39 Transits of stars observed at Salina Cruz, Mexico, by Lieut. J. A. Norris, U. S. Navy, 7oit!t transit Wo. 1^03, to ,1'lcyininc the con-ection of sidereal chronometer Negus No. i2gs. Date. Name of Star. 4J c E. -a '0 d J? Transit over mean of threads. Flexure and ill- equality of pivots. Level. Azimuth. Aberra- tion and coUi- mation. Rate. Seconds of corr. transit. R.A. Chronometer correction. V. 1.SS9. Feb. IS 17 Camelop. h. m. s. 6 13 16.043 s. +0- 475 s. — 0. 270 .1. — I. 290 + /.'i56 s. — 0. 115 s. 15-999 h. VI. s. 5 19 41-485 h. m. i. -0 S3[34-SI4] Groom. 966. . . 6 1 8 29. 064 +0-629 -0. 355 -2.651 +2. 024 — 0. too 28.611 5 24 54-451 [34- 160] . . . ip' Oiionis . . . . 6 22 17. 299 +0-317 -0. i8i +0. 096 +0.532 —0. 089 ■7-974 5 28 43. 603 34-371 +0- 003 fr' Orionis .... 6 23 29.371 +0. 294 -0 168 +0. 298 +0. 528 —0. 086 30. 237 5 29 55-909 34- 328 — ^0. 040 " Orionis . . 6 26 44.016 +0. 298 — 0. 17s +0. 260 +0. 526 -0. 077 44. 848 5 33 10.465 34- 383 +0.015 130 Tauri 6 34 31.686 +o. 331 — u. 215 - 0. 022 +0-551 -0. 054 32.277 5 40 57- 909 34- 368 0. 000 «. Orionis . . . . 6 36 3. 103 +0. 288 — 0. 194 +0. 355 +0. 532 — 0. 050 4-034 5 42 29. 645 34- 389 +0.021 a Orionis .... E. 6 42 43. 523 +0.314 — 0. 246 +0. 124 +0. 529 —0.031 44- 213 5 49 9- 861 — S3 34- 352 —0.016 66 Orionis . . . W. 6 52 41. 506 -0. 309 +0- 033 -|-o. 202 -0. 567 — 0. 002 40. 863 5 59 6.680 — 53 34- 183 — 0. 185 36 H. Camelop. . . 6 55 19- 757 — 0. 497 -I-0.06I -i.796 -'-375 -|-o. oo5 16.156 6 I 41-59° [34- 566] 22 H. Camelop. . . 7 16.343 -0. 535 +0. 080 —2. 204 —1.603 -)-o. 020 12. lOI 6 6 37. 586 [34-515] 1) Geminorum , . 7 I 46. 200 — 0- 339 +0. 054 -0. 116 — 0. 612 +0. 025 45-212 6 8 10.880 34. 332 —0. 036 u Geminorum 7 9 SO- 3" —0- 339 -|-o. 066 — 0. 116 —0.612 ■\-o. 048 49- 358 6 16 14-979 34- 379 +0. on 8 Monocerotis . . 7 II 28. 407 — 0. 310 +0. 063 +0. 19s -0. 567 +0. 052 27. 840 6 17 53-457 34- 383 +U.01S V Geminorum . . 7 15 57-959 — 0. 335 +0- 074 -0. 075 — 0. 602 +0. 066 57-087 6 22 22. 589 34- 498 +0. 130 23 H. Camelop. . . 7 21 1-75° -0. 78S +0. 182 —4- 849 -3- 156 -fo. 080 53- 222 6 27 19.525 [33- 697] y Geminorum 7 24 53-417 -0. 329 +0. 077 — 0. 006 — 0. 589 -|-o. 091 52.661 6 31 18. 274 34- 387 +0. 019 f Geminorum . . W. 7 30 41-853 —0. 344 +0. 083 -0. 170 — 0. 625 +0. 108 40. 90s 6 37 6.476 — S3 34- 429 +0. 061 Assuming a' = + o. 801 + da' circle E. «'/ = + o. 971 +(/«" " W c = + o. 575 + dc " E. AT = — oh S3"> 34S.36S + rf^. NORMAL EQUATIONS. O = — O. 046 + 2. 723 da' s. — I.4I3a'\dt \ +0. 117 +0. i76r/«' — o. 786(fe''+ o. 564(?r,r+ 12. 9350'/ a' = Ar o'-866 (circle west); a'' = + o».9S 4 (circle east); c = os.593" (+with circle east) . Chronometer No. 1295 at 61" 42™.9 chron. time, oh 53™ 308.31 6 + 08.017 fast, losing OM 65 per hour. Assuming a' =r + o. 957 + rfa'' circle W, ^'/=: + o. 851 +a'3" " E. c =-fo. 637+^^ " E. AT = — oh 53"! 308.320 + (//. S da' = 0. 091 da" = + 103 dc = 0. 044 dt =z ODD 40 TRLBGUAPHIC DETERMINATION OP LONGITUDES Transits of stars observed nl La LH'crfa,!, Salvador, by Lieut. J. A. Norris, U. S. Navy, ivith transit No. /joj, to determine the correction of sidereal chronom- eter Ne-^'ii^ No. I2gj. Date. 1889. Mar. 9 Name of Star. 25 Monocerotis a Canis Minoris , Groom. 1374 . w' Cancri . . . . X Germinorum 3 UrSK Majoris . Br. 1 147 . 20 Navis . . P Cancri . . . 30 Monocerotis . ts Ilydraa . . . y Cancri . . . a Cancri . . . e Hydr?e . . . C Hydra; . . p Ursfc Majoris n" UrsEE Majoris W. aj x: '0 6 •A Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate. s. Seconds of corr. transit. R. A. Chronometer correction. V. h. III. s. s. .r. s. s. h. m. s. h. 111. s. s. 8 20. 829 +0. 301 +0- 033 -I-0.018 +0. 382 — 0. 150 21.413 7 31 45-775 -0 28 35 638 +0. 149 824. 669 +0.313 +0.031 -|-o. 008 +0. 383 — 0. 143 5.261 7 33 29- 804 35 457 — 0. 032 8 15 29.579 +0. 566 -fo. 041 — 0. 189 + 1. 400 — 0. 097 31.300 7 46 55- 335 [35 965] 8 22 48. 003 +0. 341 +0. 024 — 0. 014 +0. 423 —0.071 48. 706 7 54 13-305 35 401 —0. 088 8 25 17. 163 +0. 346 +0.024 —0.017 +0.432 — 0. 062 17.886 7 56 42, 443 35 443 —0. 046 8 30 21. 064 +0. 496 +0. 038 — 0. 134 + I.OS4 — 0. 044 22.474 8 I 47. 118 [35 356] 8 34 10. 307 -|-o. 603 -|-o. 050 — 0. 218 + 1.586 —0.031 12.297 8 5 36.990 [35 307] 8 36 49. 174 +0. 286 +0. 026 -|-o. 030 +0. 395 — 0. 022 49. 889 8 8 14.412 35 477 — 0.012 8 39 4- 917 +0.319 +0. 030 -)-o. 004 + 0.386 — 0. 014 5.642 8 10 30. 162 -0 28 35 480 —0. 009 8 48 43. 279 —0. 302 +0. 284 — 0. 034 — 0. 422 +0. 020 42. 825 8 20 7. 341 -0 28 35 484 - 0. 005 9 I 33-796 — 0. 311 +0. 270 — 0. 020 — 0. 422 +0. 065 33.378 8 32 57-980 35 398 —0.091 9 5 28. 179 -0. 336 +0. 289 4-0.018 — 0. 454 +0.078 27. 774 8 36 52- 301 35 473 —0.016 9 6 59. 123 — 0. 331 +0. 286 +0. oil — 0. 444 + 0. 084 58. 729 8 38 23. 147 35 582 +0. 093 9 9 3°- 340 — 0- 317 +0.275 — 0. 014 —0. 424 + 0.092 29. 952 8 40 54.449 35 503 +0. 014 7 9 18 8.033 -0. 314 +0. 295 — 0. 014 — 0. 424 +0. 122 7.698 8 49 32. 166 35 532 +0. 043 7 9 21 9. 686 —0. 489 -Ho. 481 +0. 253 — I. 127 +0. 133 8-937 8 52 33-510 [35 427] 7 9 29 15. 086 —0. 484 +0. 554 -|-o. 246 — I. 104 +0. 161 14.459 9 38. 945 -0 2S[35 514] NORMAL EQUATIONS. Assuming a' = + 0.067 + "'''' circle E, fo=: — o. 049 + 4. 618 (/a' — 4. 321 nt a" = — 0.145 + «'<^" " W- I —0.025 +2. 486 (/ + 0.204 +3.lS3fl'rt"+ \.0-i,2 dc— \.']22 dt + 0. 891 — I. 467 da' + 4. 032 da" + 23. 946 dc -[- I. 022 dt \^ — 0.046 — o.ogoda' — i. y22 da" -[- I. 022 dc -\- 14. SSg dt «' = + 0^.475 (circle east); a" ^ — 0^.275 (circle west); fi=o'.6oS (+ with circle east). Chronometer No. 1295, at 7'' I5'".S chron. time, o'' 28'" 2i'.426 -^ o^.oaS fast; losing 0M89 per hour. da" = — o. 021 dc = — o. 033 dt = + o. 003 IN MEXICO, OENTllAL AMERICA, THE WES'! INDIES, ETC. 41 TransUs of stars o/>srnu:/ at La Libni.ul, Salvador, by T.inil. J. A. AWrh, U. S. Navy, wi/h transit No. 1503, to ,l.i,'n„ia,- the correction of sidereal chronometer A'(;^'v/v No. I2gj. Date. a Name of star. u •r-. u 6 7 Transit over mean of threads. Flexure and in- equality of pivots. s. -0.316 I,evcl. s. +0.038 .Vziniuth, Aberra- tion and colli- mation. -0-' 585 Rate. s. -0.417 Seconds of corr. transit. s. 26. 009 R. A, Clironometer correction. V. 1SS9. Mar. 1 3 OrionLs . . /;. ni. s. 6 17 27.309 s. — 0. 020 h. 5 /;/. s. 49 9- 440 //. m. s. — 28 16. 569 s. -0. 057 1 I^eporis 7 6 19 38. 569 — 0. 2,SS +0.039 -0. 089 -0. 598 -0. 410 37- 223 5 5 1 20. 704 16.519 — 0. 107 / Geminorum . 6 6 59 35-651 ~o. 328 +0. 113 +0. 010 — 0, 605 — 0. 276 34- 565 6 31 17.887 16.678 +0. 052 15 Monocerotis 7 7 3 9-589 -0.319 +0. Ill — 0. 012 -0.589 — 0, 264 8.516 6 34 51-849 16.667 +0.041 e Geminorum • 7 7 5 -3-869 —0.341 +0. 121 +0. 042 — 0. 641 -0. 257 22. 793 6 37 6.073 16. 720 +0. 094 s Geminorum 7 7 721. 206 -0- 323 +0. 116 — 0. 001 -0. 595 — 0. 250 20. 153 6 39 3- 509 16. 644 +0.018 Canis i\!ajoris . 7 7 17 19-693 -0. 291 +0. 105 — 0. 082 -0. 593 — 0. 217 iS. 615 6 49 2. 039 16. 576 — 0. 050 ) Canis Majoris . 7 7 27 2.029 —0. 286 +0. 100 — 0. 094 — 0. 602 — 0. 184 0. 963 6 58 44-319 16. 644 +0. 018 ^5 Camelop. . . 7 7 36 3-743 -0. 873 +0. 283 + 1-359 -4-515 — 0. 154 59. 843 7 7 43-724 [16. 119] 1 Geminorum 7 7 40 0. 550 — 0. 328 +0. 102 +Q. 01 I —0. 606 — 0. 141 59- 58S 7 II 42.945 16. 643 +0.017 Piazzi vii, 67 3 7 47 38- 289 -0. 495 -fo. 135 +u. 422 -..596 — 0. 115 36. 640 7 19 20.348 [16. 292] ^4 Lyncis w. 5 S I 55.5.6 -0.428 fo. 078 +0. 259 -I. 125 — 0. 067 54- 233 7 33 37-311 —0 28[i6. 922] Groom. 1374 . . E. 2 8 15 10. 319 -|-o. 566 -0. 273 -0. 509 + 1.984 —0. 023 12. 064 7 46 55-1" -0 28[i6.953] (ji Cancri 7 8 22 29. 154 +0. 341 —0. 163 — 0. 037 +0. 599 4-0. 002 29. 8g6 7 54 13-239 16.657 +0.031 X Geminorum 7 8 24 58. 204 +0- 346 — 0. 165 — 0. 045 +0.612 -f 0. 010 58.962 7 56 42- 385 16.577 — 0. 049 C Cancri 7 8 34 6. 926 +0- 330 -0- 153 — 0. 013 +0. 568 -(-0.041 7.699 8 5 51-120 16.579 — 0. 047 ,^ Cangri . . 7 8 38 45.466 +0-319 —0. 146 -l-u.OII +0. 547 -|-o. 056 46. 753 8 10 30. 114 16. 639 +0.013 1 Leonis . . 7 10 29 11. 117 +0.329 — 0. 180 — 0. Oil . +0. 565 +0.428 34- 248 10 I 17.701 16. 547 — 0. 079 '/. Hydrx 7 10 33 26. 899 +0. 291 -0. 153 +0. 069 +0.552 +0. 441 28. 099 10 5 11.462 16.637 +0. on k Leonis 7 10 38 47-274 +0. 339 -0. 172 — 0. 032 +0.591 +0. 458 48. 458 10 10 31.791 16.667 +0. 041 >' Leonis . . 7 10 42 7-45° +0- 334 -0. 165 — 0. 020 +0.576 +0. 469 8.644 10 13 51.965 16. 679 +0.053 /' Leonis 7 10 55 14. 210 +0-319 — 0. 146 +0. 010 + 0. 548 +0.513 15-454 10 26 58.827 16. 627 +0.001 35 H. Ursx Majoris 7 II 3 23.886 +-0- 505 — 0. 224 -0. 3S0 + 1-554 +0. 541 25. 882 10 35 9-433 [16,449] « Ursa; Majoris E. 7 II 25 9. 229 + 0. 447 —0. 204 — 0. 258 + 1.164 +0.614 10. 992 10 56 54- 323 -u 28[i6. 669] NORMAL EQUATIONS. '0 = — 0.222 + 4.051 (/«' + 2.630 (/c -)- 0.123 I* " — 0.132 + 3.363 fl'a" — 4.146 dr — 1.765 r// -\- 0.814 + 2.630 da' — 4.146 da" -|- 28.977 dr -\- 0.449 '* + 0.130 + 0.123 da' — 1.765 da" + 0.449 '^^ + 19.220 dt a' = — o''.l87 (circle -west) ; a" =_ -\- OM59 (circle east) ; c = os.560 (+ with circle east). Chronometer No. 1295, at 8'' 22"'.o chron. time, o'' 28'" i6".626 -J- o».oo8 fast, losing o».2oi per hour. Assuming a' = — 0.266 + da' circle W. a" = ^ o.\(><) ^ da' ' " E. c = + 0.596 -|- dc " E. /\T = — qI' 28'" i6«.62l + dl. whence da' = + 0.079 da "= — o.oio dc ^= — 0.036 dt = — 0.007 42 TELEGRAPniO DETERMINATION OF LONGITUDES Transits of stars observed at La Libertad, Salvador, by Lien/. J. A. Norris, U. S. Navy, with transit No. r^os, to determine the correction of sidereal chronometer Negus No. i2gS- Date. Name of Star. u '^ n dj ^-. d Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and coUi- mation. Rate. Seconds of corr. transit. R. A. Chronometer correction. V. J 889. iMar. 14 1^ Geminorum E. li. m. s. 6 44 25. 754 s, +0.337 s. — 0. 195 s. — 0. 039 s. +0. 701 — 0. 135 s. 26. 423 A. m. 1 6 16 14 539 //. ?«. J. -0 28 11.884 +0.025 8 Monocerotis . . 6 46 4. 289 +0.312 — 0. 185 +0. 035 +0. 649 — 0. 130 4.970 6 17 S3 051 II. 919 +0. 060 a Argus 6 49 40. 186 -\-o. 210 — 0. 131 +0. 345 + 1.066 — 0. 117 41-559 6 21 29 616 [11-943] . . . 23 H. Camelop. . . 6 55 26. 393 +0.711 — 0. 483 — I. 170 +3-613 -U.097 28. 967 6 27 16 895 [12.072] . . . y Geminorum 6 59 29. 001 +0. 328 — 0. 235 —0.012 +u. 675 —0. 084 29- 673 6 31 17 869 1 1 . 804 -0- 055 IS Monocerotis 7 3 3-013 +0.319 -0. 238 +0.014 +0. 657 —0.071 3-694 6 34 51 831 11.863 +0. 004 t Geminorum 7 5 17-153 +0. 341 — 0. 262 — 0. 052 +0. 716 — 0. 064 17.832 637 6 054 11-778 —0.081 s Geminorum 7 7 14-641 +0. 323 -0. 254 +0. 002 +0. 664 -0. 057 15-319 6 39 3 491 11.828 — 0. 031 43 Camelop. . . 7 9 54-521 +0. 498 —0. 405 — 0. 528 + ,.807 — 0. 048 55- 845 6 41 44 134 [11-711] . . . 24 II. Camelop. E. 7 12 2.686 -)-o. 627 -0. 522 — 0. 920 +2. 902 — 0. 041 4-732 6 43 52 604 — 28[I2. 128] C Geminorum W. 7 25 44-419 —0- 334 +0. 032 +0. 028 — 0. 734 +0. 006 43-417 6 57 31 584 — 28 11.833 — 0. 026 -5 Camelop. 7 35 59- 564 -0.873 +0. 222 + i.49o -5- 348 -|-o. 041 55-096 7 7 43 578 [11-518] 'A. Geminorum 7 39 55-740 -0.328 +0. 097 -f-o. 012 -0.717 +0. 054 54-858 7 II 42 929 1 1 . 929 -|-o. 070 Piazzivii, 67 7 47 33-814 -0. 495 +0. 174 +0. 463 —I. 891 +0. 080 32- 145 7 19 20 300 [11.845] . . . P Canis Minoris . 7 49 20. 730 -0.317 +0. IIS — 0. 018 — 0. 695 +0. 086 19. 901 7 21 8 106 11-795 — 0. 064 25 Monocerotis . . 7 59 58-417 -0. 301 -f-o. 109 — 0.061 — 0. 688 +0. 123 57-599 7 31 45 698 II. 901 +0. 042 a Canis Minoris 8 I 42. 360 -0.313 -|-o. Ill — 0. 029 — 0. 6go -)-o. 129 41. 568 7 33 29 732 11.836 -U.023 IC Geminorum 8 5 57-733 —0. 340 +0. 112 +0. 044 -0.756 +0. 143 56.936 7 37 44 995 1 1. 941 +0. 082 Groom. 1374 . W. 8 15 9. 221 — 0. 566 +0. 137 +0.657 -2.525 +0. 175 7.099 7 46 55 054 — 28[l2. 045] (o = - NORMAL EQUATIONS, -o. 392 + 5-734 a^«' — 3. 917 at — 0.645* Assuming a' = -f- o. 196 -|- da' circle E «'/= — o. i74 + rf«" " W. J +0.387 +4.534rfa"+ 4.852^',:- 1.089*^ c =-\-o.yig-\-dc " E. ] + 1.614 — 3.9i7a'a:/-)-4. 852<&" + 2S.8i3(f(r+ o. 945 . I2()^. Date. Name of Star. 1889. Mar. 30 Groom. 200 1 ^ Virginis Groom. 2029 . . r Cootis 89 Virginis Bootis .... Virginis . . d Bootis . . . 4 Urea; Minoris . '/- Virginis . 5 Ursa; Minoris . C Bootis . /' Virginis 109 Virginis 8 I.ilira- cfi I.ibnc ■Si ■u c y. Transit over mean of threads. Flexure and in- e(|uaUty of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate. Seconds of corr. transit. R. A. Chronometer correction. V. It. in. s. J. s. i. J. a. .V. //. VI. s. //. in. s. s, 1:. 7 13 35 38.579 +0.510 — 0. 210 — 1.292 + 0-559 — 0. 136 38. 410 13 23 21.868 — I3[i6. 542] . . . 7 13 42 19-236 +0- 309 —0.157 +0. 084 +0. 281 — 0. 120 19- 633 13 29 3.170 16. 463 +0. 127 7 13 47 50.871 +0. 496 -0. 2S8 -I. 198 -|-o. 900 —0. 105 50. 676 13 34 34- 468 [16.208] . . . 7 13 5S 16.320 +0. 329 ~o. 218 -0.0S3 -f-o. 296 — 0. 084 16,590 13 42 0. 222 16.368 +0. 032 5 13 S7 7-166 +0. 2S9 -0. 197 +0. 21S 4-0. 295 —0.079 7.692 13 43 51-431 16. 261 -0. 07s 7 \\ 2 40.944 +0. 330 -~o. 239 — 0. 061 +0. 297 — 0. 064 41.207 13 49 24. 960 16. 247 — 0. 089 7 14 9 16. 780 +0.311 — 0. 232 +0. 06S +0.281 — 0. 046 17. 162 13 56 0.740 16.422 +0. 0S6 Is. 7 14 18 37.221 +0, 33S -0. 253 — 0. 118 +0.312 — 0. 020 37.480 14 5 21. 240 — 13 16. 240 — 0. 096 \V. 7 14 22 40. 221 —0. 600 — 0. 149 +0. 636 -I-S53 — 0. 009 38. 546 14 9 22. 490 — I3[i6. 056] 7 14 35 46- 7S6 —0. 307 —0. 056 — 0. 032 — 0. 321 +0. 027 46. 097 14 22 29. 847 16. 250 — 0. 086 7 14 41 8. 243 -0- 559 —0. 085 +0. 543 -1-345 +0. 042 6.839 14 27 50.300 [16.539] . . 7 14 49 8. 749 — u. 324 -0. 03s -|-o. 008 -0-331 -f 0. 064 8. 131 14 35 51-652 16.479 +0. 143 7 14 50 30. 370 —0. 303 —0. 030 — 0. 041 —0.322 +0. 068 29. 742 14 37 13-448 16. 294 — 0. 042 7 14 S3 55-903 — u. 312 — u. 026 — 0. 022 —0.321 +0.077 55- 299 14 40 39. 018 16.281 -0. 055 7 14 57 50.659 - 0. 292 —0. oiS — 0. 067 -0. 333 +0. 08S 50- 037 14 44 33- 659 16.378 -)-o. 042 \v. 7 14 58 2. 096 — u. 292 — u. 018 — 0. 067 — 0. 333 +0. 088 1-474 14 44 45. 120 -0 13 16.354 +O.OI8 NORMAL EQUATION.S. s. Assuming a' ^- -\- o. 41 ^ -\- da' circle E. (o^ — o. 127 -)- 3. 222(/rt' — 2.889«'c — 0.645n'/'| whence ,'/«' =-|-o.oi7 Ursx Majoris . n- Urs.e Majoris . e Hydra: S3 Cancri I Draconis, H. . . e Leonis . . Leonis w. w. Transit uvor noan of tlnx-ad.s. Flexure aiitl in- equality ui pivots. Level. /i. in. J 805 086 s. -0.558 s. -0.55S S 5 23 929 1—0. 418 —0.412 8 9 52 229 ,— u. 342 -0.372 8 14 56 593 — u. 468 — 0. 520 8 19 S74 i-o. 329 -0. 368 « 23 39 S19 ,—0.319 -0. 358 8 33 17 004 -u. 305 — 0. 329 8 39 27 513 —0.332 -0. 340 8 46 7 559 —0.313 -0. 294 9 37 440 +0. 346 — 0.092 9 2 40 650 +0. 316 —0.096 9 5 41 736 : +0.461 — u. 160 9 13 47 000 i-f 0. 458 -0. 199 9 21 44 SOI 1+0.312 — 0. 154 9 25 56 321 +0.329 — 0. 1 68 9 34 25 S'4 +0.737 -0. 393 9 48 ^-^- 824 1+9.320 — 0. 162 9 52 42 ■S3 +0.337 — 0. 162 Azimuth — o. 072 -0.034 — o. 007 — o. 051 — o. 003 +0. 001 +0. 006 — o. 004 +0. 003 —0.071 +0.015 — o. 403 — o. 392 -|-o. 026 — o. 023 —'•193 +0. 003 — o. 044 Aberra- tion and coUi- mation. Kate. Seconds of coir. transit. s. s. s. — 0. 533 — 0. 105 3. 200 — 0. 296 —0. 150 22.589 — 0. 164 — 0. 136 5 1 . 208 — 0. 401 — 0. 122 55.031 -0. 152 — u. no 59.912 — 0. 147 — 0. 096 38. 900 -0. 145 — 0. 068 16. 163 -0.155 -u. 051 26. 631 — 0. 145 — 0. 031 6.779 +0. 123 +0. on 37-757 +0. 106 +0.017 41. 008 +0. 281 +0. 025 41.940 +0. 275 +0. 049 47. 191 +0. 105 +0.072 44. 862 +0. no +0. 084 56.653 +0. 738 + Q. 108 25.511 +0. 107 + 0. 149 23. 241 +0. IIS +0. 162 42.591 K. A. Chronometer correction h. in. s. 7 46 53- 876 7 52 13.530 7 56 42.057 8 I 46.«So 8 5 50.829 8 10 29. 831 8 20 7.018 8 26 17. 609 8 32 57.680 8 47 28. 630 8 49 31.892 8 52 32.697 9 o 38. 176 9 8 35.772 9 12 47.592 921 16. 499 9 35 14.097 9 39 ii- 575 h. in. 13 [9 324] [y "59] 9 151 [8 951] 9 083 9 069 9 145 9 022 13 9 099 13 9 127 9 116 [9 243] [9 015] 9 090 9 061 [9 0.2] 9 144 13 9 016 +0.057 o. on o. 025 0.051 — o. 072 o. 005 +0. 033 +0.022 — o. 004 -o. 033 +0. 050 — o. 078 : + o. 028 + da' circle \V. + 0. 1 88 + ,/<;'' " K. 0.128 -{-de " E. -qI" 13m 98.093 + dt. XURALVL EQUATIONS. (• o = + u. 037 + 3. 910 i/rt' + 4.6i2de- I +0.018 +4. 4S2a'rt" — 5.3961!'^- ] + o. 058 + 4 652 da' — 5. 396 da" + 24. oog ,/c I — 0.020 — 1. 80S 13"' 98.094 + o'.oog fast, losing 0».I74 per hour. April 2 n Geminorum 1 E. 7 7 50 49. 626 +0. 337 — 0. 163 —0. 035 +0. 091 — 0. 129 49. 727 7 37 44- 658 — 13 5. 069 +0. 093 Groom. 1374 . . 7 7 59 58. 943 +0.558 — 0. 278 —0. 452 +0. 305 — 0. 103 58 973 7 46 53. 80s [5 168] 53 Camelop. . 7 8 5 18.464 +0.418 — 0. 2 1 6 — 0. 213 +0. 169 —0. 088 18 534 7 52 13.488 [5 046] (,)i Cancri . . . 7 8 7 17.744 +0. 338 — 0. 179 —0. 038 +0, 092 —0. 082 17 875 7 54 12.899 4 976 0.000 X Geminorum 7 8 9 46.816 +0. 342 -0. 187 -0. 04s +0. 094 -0.075 46 945 7 56 42. 039 4 906 —0. 070 3 Ursce Majoris, H. 7 8 14 50. 750 +0. 468 —0. 276 — 0. 322 +0. 230 — u. 061 50 789 8 I 46. 030 [4 759] f Cancri . . . 7 8 i8 55.627 f 0.329 — 0. 2og — 0. 017 +0. 087 — 0. 049 55 768 8 5 50.813 4 955 — 0. 021 20 Navis . 7 8 21 18.826 +0. 293 — 0. 19s +0. 064 +0. 086 —0. 042 19 032 8 8 14.028 5 004 +0. 028 ■i Cancri E. 7 8 23 34. 590 +0.319 — 0. 223 +0. 004 -(-0. 084 -0. 03s 34 739 8 10 29. 816 — 13 4 923 -0. 053 Urste Majori.s W. 7 8 34 7- 993 — 0. 420 — 0. 025 +0. 441 — 0. 254 —0. 005 7 730 8 21 2. 610 — 13 [5 120] Groom. 1446 . . 7 8 40 26. 693 — 0. 524 -0. 033 +0. 901 — 0. 447 +0.013 26 603 8 27 21.887 [4 716] T Hydric . . 7 8 46 2. 979 -0.313 — 0. 022 — 0. 037 — 0. 123 +0. 029 2 513 8 32 57. 665 4 848 — 0. 128 -y Cancri .... 7 8 49 57. 426 -0. 334 — 0. 024 +0. OSS — 0. 133 +0. 041 57 031 8 36 51.972 5 059 +0. 083 'i Cancri .... 7 8 SI 28.274 -0. 330 — 0. 025 +0.037 — 0. 130 t- 0.045 27 871 8 3S 22. 833 S 038 { 0.062 £ Hydra." . . 7 8 S3 59.561 —0. 316 — 0. 025 — 0. 022 — 0. 124 4-0. 052 59 126 8 40 54. 145 4 981 +0. 005 p Ursae Majoris 7 9 5 37.729 — 0. 461 — 0. 044 +0. 62s -0. 329 +0. 086 37 606 8 52 32.644 [4 962] K Cancri 7 9 14 49. 864 —0.321 — 0. 036 — u. OOI -0. 125 + 0. 112 49 493 9 I 44.488 5 005 +0. 029 Hydraa .... W. 7 9 21 41.086 —0.312 — 0. 038 -u. 041 -0. 123 + 0.132 40 704 9 8 35.758 -0 13 4 946 — 0. 030 NORM A I, EQUATIONS. '0= +0. 07s +4. iS5(/«' — 4.953((V— 2. 079 ((V) whence i.224 (circle west) ; a" = -\- os.324 (circle east) ; c - Chronometer N0.1295, at 22'" 34™. 2 chron. time, o'» 14"' 53^845 J- ■l.^iTidcJf- 0.3300'/'^ wh 2. 708 dc -(- o. 003 dt I 23. 178^1: -|- o. 043(* I o. 043 dc -{- 13. 269 dt j = 0M83 ( -|- with circle east). 0^^.009 slow, losing 01.043 per hour. s da' = + 031 da" ;= — 024 dc = + 010 dt ^= 002 Nov. 28 01 Ceti ' . 38 Cassiop. V Piscium 40 Cassiop. 43 Cassiop. f Piscium o Piscium y Arietis fl Arietis 55 Cassiop. ^1 Ceti Arietis o Ceti c Cassiop. f» Ceti . V Arietis . -f- da' circle E. f o = -f o. 093 -1- 3. 499 da' + 0.231 -I- o. 300 — 3. 053 - o. 160 — o. 363 da' — o. 373 da" //— _)_ o. 314 -I- da" " W. I + o. 231 -|- 3. 129 da" -f 2. 667 dc -- o. 373 dt 1 _j_ r> ^r^r^ -> r^ e -, ^^ij/ _^ 2 . SSj da" -\- 2 3 . 246 dc — o. iS6 dt I 3.0^,3 dc — o. 363 dt"\ whence da' = — 0.034 da" =r — 0.064 dc AX = -|- o'' 14" 55". 356 -\- dt 1 — o. 160 — o. 363 da' — o. 373 da" — o. 186 dc -\- 13. 444 dt J a' -— 4- o».434 (circle east) ; a" = ^ 0^.250 (circle west); 43'". 2 chron. time, o^ 14m 55^.365 -J- o''.oi2 slow, losing o".o67 per hour. — o.oio dt = -|- 0.009 IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 47 Transits a/stun observed at St. Xu/whis J/i^^ ilcleniuHL' Ike curn'ilioii of nJcrcal cJironurnelci' Date. 1889. Nov. 29 tj Aquari 3 1 Cephei 30 Cephei C Pegasi . X Pegasi . T Aquarii fi Pegasi . X Aquarii TT Cephei ip Aqviarii y Piscium o Cephei V Pegasi . K Piscium ft Piscium 70 Pegasi . J Cephei T1 nt J3 a> u /> w. w. , E. 7 7 E. 7 Transit uvcr mean of threads. //. ffl. s. 22 14 44. 497 22 iS 7.400 22 19 48. 250 22 21 o. 850 22 26 16. 520 22 28 48. 289 22 29 44. 170 22 31 54-796 22 49 26. 714 22 S3 39-034 22 56 29.339 22 59 8. 757 23 4 55- 120 23 6 19. 250 23 7 24-933 23 837.131 23 19 54-257 Flexure and in- equality of pivots. -o. 295 — o. 647 — o. 506 — u. 316 -o- 341 — o. 269 -u- 344 — u. 281 -^o. 690 +0. 2S4 +0. 301 +0- 554 +0-341 +0- 297 +0- 307 +0.319 -|-o. 760 ivcvel. — 0.071 o. 138 o. 103 o. 061 o. 053 o. 036 o. 046 0-034 — o. 250 o. 118 — o- 137 o. 269 o. 191 — o. 171 ■0. 181 o. 194 o. 577 Azimuth. +0. 026 — u. 204 — o. 112 -|-o. 012 — o. 004 +"■ 043 — o. 006 +0- 035 — o. 684 "|-o. 098 +0. 065 — o. 424 — o. 012 -|-o. 072 +0- 053 +0. 030 —0.819 Aberra- tion and colli- mation. s. -o. 18O — o. 639 — o. 410 — o. 189 — o. 202 — o. 192 — o. 204 -o. 188 +0-557 +0. 147 +0. 146 +0. 382 +u. 158 +0. 146 +0. 147 +0- 149 +0. 650 Rate s. -o. 034 — o. 030 — o. 028 — o. 027 — o. 021 — o. 018 — o. 017 — o. 014 4-0. 006 -fo. on +0. 014 +0. oi8 -f-o. 024 -|-o. 026 -|-o. 027 -f-o. 028 -f o. 042 Seconds of corr, transit. K. A. Chronometer correction. V. S'. A. III. s. h. in. s. J. 43- 937 22 29 40. 801 -\-o 14 56.864 -|-o. 004 5-742 22 33 2.572 [56.830] 47.091 22 34 44.012 [56.921] 0. 269 22 35 57.222 56.953 ■— 0. 085 15-899 22 41 12.703 56. 804 -|-o. 064 47.817 22 43 44. 654 56.837 +0.031 43-553 22 44 40. 426 56- 873 — 0. 005 54-3'4 22 46 51. 211 +0 14 56. 897 —0. 029 27-033 23 4 23. 959 +0 i4[56-926] 39- 456 23 8 36.331 56-875 — 0. 007 29. 728 23 II 26.577 56. 849 -1-0. 019 9. 018 23 14 6. 269 [57-251] 55- 440 23 19 52.265 56.825 +0- 043 19. 620 23 21 16.455 56. 835 +0- 033 25. 286 23 22 22. 176 56. 890 — 0. 022 37-463 23 23 34- 381 56.918 — 0. 050 54-313 23 34 SO- 617 +0 I4[56.304] NORMAL EQUATIONS. Assuming a' = -)- o. 078 -|- t/a' circle W. f o^ — o. 001 -|- 2. 666 (/«' -|- \.\'~,(idc^ o. 489 (A ") whence i/a' = — 0.004 a" = -f O. 272 -f a'a'-' " E. J -f-0.228 -f 4. 047 a'a'-' — T,.0\i,dc-\- o.l-}f>dt\ da" =: — O. 053 c =-|-o. 161 -t-tZir " E. I — o. 264-I- I. I56a'<7' — 3. 044(/a" -|- 21. 772 Pegasi . . w Piscium Br. 6 Assuming a' ^ -)- o, c AT = -)-o. w. 18 2.871 -f-o. 647 — 0. 156 -0. 033 -f-o. 670 — 0. 036 3-963 20 58. 409 +0.316 — u. 094 -(-0. 002 -t-u. 198 — 0. 033 58- 798 26 13.910 +0. 341 -0. 132 — 0. 001 -f-o. 212 — 0. 027 14- 303 28 45-954 -f-o. 269 — 0. 114 -f-o. 007 -f-o. 201 — 0. 025 46. 292 29 41-587 +0. 344 — 0. 151 —0. 001 +0.214 —0. 024 41.969 31 52.390 -f-o. 281 — u. 132 -f-o. 006 +0. 197 — 0. 022 52.720 44 16. 856 +0. 324 -0. 175 -f-o. 001 +0. 201 —0. 009 17. ig8 49 24.615 -|-o. 690 — 0. 370 -0. 037 +0. 744 — 0. 004 25- 638 56 27.807 +0. 301 -0. 153 -|-o. 004 +0- 195 +0. 003 28.157 4 54- 333 -0- 341 -f-o. 062 -f-o. 001 -0. 255 +0. on S3- 8n 6 18.486 — 0. 297 +0. 055 — 0. 008 -0. 235 -^0.013 1S.014 7 24.217 — 0. 307 +0- 057 — 0. 006 -0. 236 +0.014 23- 739 8 36- 437 -0. 319 -f-o. 060 — 0. 003 — 0. 240 +0.015 35-950 19 53-479 — 0. 760 +0- 154 -f-o. 090 -I. 046 +0. 026 5'- 943 27 41-236 -0. 550 -|-0. 121 -f-o. 046 — 0. 606 f 0. 034 40. 281 31 54-679 -0. 332 +0.075 — 0. 001 —0. 248 +0. 038 54-211 38 40.807 — 0. 308 +0. 073 — 0. 006 — 0. 236 +0. 045 40- 375 SS 3- 693 -0. 736 -f-o. 196 -f-o. 085 — 0. 995 +0. 062 2.305 22 33 2 498 22 35 57 210 22 41 12 689 22 43 44 638 22 44 40 406 22 46 51 199 22 59 15 691 23 4 23 8S3 23 II 26 5^1 23 19 52 246 23 21 16 444 23 22 22 165 23 23 34 368 23 34 50 533 23 42 38. 869 23 46 52 546 23 53 38-831 10 358 +0 i4[58-535] 58.412 58.386 58. 346 58.437 58.479 58. 493 [58. 245] 14 58.404 +0 14 58.435 58. 430 58.426 58.418 [58. 590] [58, 5SS] 58.335 58.456 +0 I4[58.0S3] +0. 008 0.034 +0. 074 —0.017 — o. 059 — o. 073 +0. 016 — o. 015 — o. 010 — o. 006 +0. 002 -o. 085 -o. 036 NORMAL EQUATIONS. = + o. 083 + 3. 065 da' — 1 . 446 dc + o. 658 (// — 0.165' +3. 879fl'a'M- 3.S82(i'^- o. 325 rA — 0.421 -- 1.446 5 — 0.012 ,i Aquarii 22 33 45 436 -1-0. 265 0. 000 +0. 344 +0. 337 —0. 029 46-353 22 48 47- 294 0.941 +0. 012 a Pegasi . . . 22 44 14 001 +0- 324 0. 000 +0. 053 +0- 334 —0.021 14. 691 22 59 15-667 0.976 — 0. 023 TT Cephei 22 49 22 786 -|-o. 690 0. 000 -1.746 + 1-2 -,2 —0.017 22. 945 23 4 23.731 [0. 786]

• Assuming a' = + 0. 531 + <&' circle E. f 0= -o. 097 + 3. Ii7 i5'"o''.955+<*. (^ .-0.029 + 0. 975 ^«' +0.636 Aquarii ) Piscium Cephei 4 Cassiop. K. Piscium 6 Piscium . 70 Pegasi . 1 Piscium 41 H. Cephei (p Pegasi . . (J Piscium 33 Piscium . } Pegasi . . ( Ceti . 44 Piscium K Cassiop. Transit over mean of threads. h. III. J. ^2 53 34- 59G 22 56 24. 964 22 59 5.964 23 + 56.214 23 6 14.884 23 7 20. 606 23 8 32. 854 23 19 14.867 23 27 36.021 23 31 49- 763 23 38 35- 993 23 44 38.451 23 52 30-637 23 58 45-603 o 4 42. 187 o II 42. 236 Flexure and in- equality of pivots. —0 284 —0 301 —0 554 — 494 — 297 — 307 — 319 — 306 +0 550 +0 332 +0 308 +0 284 +0 324 +0 27S +0 299 +0 500 Level. Azimuth + o. 103 -fo. no +0. 204 +0. 188 +0. 113 +0. 118 +0- 124 o. 125 — o. 119 -0. 081 -0. 090 -0. 096 -0. 128 — O. 123 o. 144 -0. 265 +0. 146 -f-o. 096 — o. 633 — o. 460 +0. 107 -|-o. 080 +0. 044 f o. 084 —0.81 1 4-0. 010 O. lOI +0. 190 -|-o. 041 -|-0. 212 +0. 135 — o. 621 Aberra- tion and coUi- mation. Rate. Seconds of corr. transit. s. J. J. —0. 428 — 0, 025 34. 108 —0. 425 -0. 023 24.421 — 1. HI — 0. 021 3-849 -0. 896 —0.017 54- 535 -0. 425 — 0. 016 14.366 —0. 427 —0.015 20. 055 -0. 435 — 0. 014 32. 254 —0. 427 — 0. 006 14- 337 +0. 993 -|-o. 001 36. 635 -f 0. 406 -f 0. 004 50. 434 +0. 387 -(-0. 009 36. 708 +0. 387 -|-o. 014 39. 230 +0. 398 -(-0. 020 31.292 +0. 390 +0. 024 46. 384 +0. 385 +0. 029 42. 891 +0. 829 -l-o. 034 42.713 R.A. h. m. 23 8 23 II 23 14 23 19 23 21 23 22 23 23 23 34 23 42 23 46 23 53 23 59 o 7 o 13 o 19 o 26 36. 283 26.513 6.077 56-551 16. 411 22. 132 34- 333 16. 472 38-736 52-513 38. 801 41-351 33-411 48. 498 44. 960 44. 824 Chronometer correction. h. m. s. +0 15 2- 175 2. 092 [2. 228] [2.016] 2.045 2.077 2.079 +0 15 2.135 -|-o 15 [2. 101] 2.079 2.093 2, 121 2. 119 2. 114 2. 069 +0 15 [2.111] -o. 07s -o. 008 +0.055 +0.023 — o. 021 - o- °35 -f 0.021 -)-o. 007 o. 02 1 — 0.019 o. 014 +0.031 NORMAL EQUATIONS. Assuming a' = 4- o. 335 -(- .io5-f-(/A l^ -1-0.043-1-0.698 (/■;' + 0.599 (/a"-!- o. 070S7 23 42 38- 178 [15-021] "P Pegasi . ... 23 31 36.499 +0-332 -|-o. 048 -|-o. 014 -f 0. 402 — 0. 020 37- 275 23 46 52. 360 15.085 -0-053 IS" I5».035 + (/? (^ — o. 008 -f- o. 047 i/a' -|- o. 546 (/a" -|- o. 094 ifc -f- 1 2. 848 lA J a' = -f- 0^.592 (circle east) ; a" ^ -f- o'i.535 (circle west); if = 0».40l (+ with circle east). Chronometer No. 1295, at 23'' 51^.3 chron. time, o'' 15"" 15^032 -J- 0^.019 slow, losing o=.o62 per hour. whence da' = — 049 da" = + 0. 053 dc ^ — 004 dt := OOI Dec. 16 la Piscium 33 Piscium a Andromeda; ) Pegasi . i Ceti . 44 Piscium /c Cassiop. y Cassiop. 44 Cephei, H. . Piscium \i Piscium 55 Cassiop. f 1 Ceti . . 67 Ceti . . Ceti . . « Ceti . . E. W. 23 38 21.519 +0. 308 -0. 186 +0. 103 +0.441 — 0. 088 22.097 23 44 24.013 -j-o. 284 -0. 171 -f-o. 194 +0- 441 — u. 081 24. 680 23 47 24.071 +0- 354 — 0. 212 -0. 07s -1-0. 498 -0.077 24- 559 23 52 16. 200 +0. 3*24 -0. 193 -|-o. 042 +0- 452 —0.071 16. 754 23 58 3'-«76 -1-0. 278 — 0. 165 -f-o. 217 +0-44+ — u. 063 31.887 4 27.774 -f-o, 299 — 0. 177 +0. 139 +0- 438 — 0. 056 28.417 II 27.507 -f-o. 500 — 0. 295 — 0. 636 +0. 943 — 0. 047 27.972. 34 46- 771 +0. 483 -0.285 — 0. 568 -f-o. 880 —0.018 47. 263 47 35- 526 — 0. 850 0. 000 -0.677 — 2. 526 — 0. 002 31.471 50 19.877 -0. 357 -|-o. 012 — 0. 029 — 0. 549 -|-o. 002 18. 956 58 8. 889 — 0. 350 -f-o. 048 — 0. 020 -0- 535 -f-o. Oil 8-043 I 50 37. 107 -0- 536 -f-o. 014 — 0. 265 — I. 176 +0. 077 35.221 I 51 53-911 — 0. 312 -f-o. 010 -f-o. 030 — 0. 483 +0- 079 53-235 I 56 13-547 — 0. 283 -f-o. 025 -j-o. 067 — 0. 481 -f-o. 084 12. 959 I 58 31- 139 — 0. 290 +0.033 -f-o. 059 — 0. 479 -1-0. 087 30- 549 2 7 2.336 — 0. 312 -|-o; 067 +0.031 -0. 483 -f 0. 098 1-737 23 S3 38- 23 59 41- o 2 41. o 7 33- o 13 48. o 19 44- o 26 44. 50 3. 1 2 48. 1 5 35- 1 13 24- 2 5 51- 279. 2 II 29. 2 13 46. 988 2 22 18. 297 659 209 092 258 368 831 409 797 157 459 558 575 778 436 +0 +0 +0 15 16. 562 16. 529 16.533 16. 504 16.481 16.414 [16-437] i5[i6. 534] I5[i6. 686] 16. 503 16.515 [16-354] 16. 543 16.477 16.439 15 16.560 0.057 o. 024 — o. 028 -f-o. 001 -f-o. 024 -f o. 091 -f-o. 002 — o. 010 — o. 038 -|-o. 028 -f-o. 066 -o. 055 NORMAL EQUATIONS. 'o = -f-o. o54-f- 2. 061 flVz' — 0.744 at -|- o. 382 (// ~ — 0.057 -|- 2. 760 (/a" -f- i.932(/c-f- o. 127 (* — o. 224 — O. 744 da' -f- 1. 932 da" -\- 19. 858 dc -^ o. 414 dt -f-o. 021 -f-o. 382 da' -\-o. 127 da" -|- 0.414 dc -\- 13. 103 dt «' = -f- o».437 (circle east) ; a" ^-\- o'. 149 (circle west) ; ^ = o'.4S8 (-f- with circle east). Chronpmeter No. 1295, at oi" 49'".o chron. time, oh 15m i6=.505 J- o«.oo9 slow, losing 08.075 per hour. Assuming a> = -f- o. 459 -f- da' circle E. «" = -|-o. i3S-f-n'a'' " W c = + o. 449 -f- de " E. /\T =-f-oi>i5'"i6».503-|^fl'.^. whence da' da" dc dt = ^0. 022 ^ -j-o. 014 ^ -f- o. 009 = — O. OOI 52 TELEGllAl'UKJ DETI'UiMlNATlON OF LONGITUDES Transih of s/ars vh,r\;,l at Si. Xi,o/,is Mule, IJayli, by Lieul.J. A. \o) rh, U. S. A'a-'v, -,ai//i /niini/ jVd. I ^oj, to determine the loricil ion of sidereal chronometer Nci^iii No. /-'lyj- Date. N.imu ot Slar. 'I'raiisit uvcr mean uf tliri.'ads. I'lcxuru and in- ei]uality of pivots. Level. A/imutli. Alierra- tion and colli- mation. Kate. Seconds Dfcorr. transit. K. A. Chronometer correction. V. E. S5 h. III. s. 23 21 40.540 J-. 40. 267 -0.136 |-o. 220 -l-u. 462 — 0. 080 s. 41-273 A. m. s. 23 36 59- 797 +0 1S89. 1.1- Aquarii III. s. 15 18.524 s. +0. 087 Dec. 17 41 11. Cephei . . . 23 27 19.057 +0. 550 — 0, 292 -0. '703 + 1.151 — 0. 072 19. 691 23 42 38. 0S2 [•8.391]

15"> 20=.3i2 + fl'if a — o. 773 dc-\- 1 . 195 fl!^ 1 whence da' = — o. 040 + 2.595a',7"+ i.-]i2,dc-\- o.i88d'/[ ^■^'' = + 0.058 dc ^ + o. 013 dt = + o. 001 IN MEXICO, CBNTEAL AMEEICA, THE WEST INDIES, ETC. 53 Transits of stars observed at St. Nicolas Mole, Hayti, by Lieut. J. A. A'orris.U. S. Navy, tvith trainil No. 1503, to determine the correction of sidereal chronometer A'cx/ii No. isc^S- Date. Dec. 19 Name of Star. q> Pegasi 20™.8 chron, time, o'' 15"' 2i''.887 -|- 0^.005 slow, losing os.o66 per hour. Dec. 20 y Cassiop. . . W. 7 34 40. 864 -0. 483 +0. 175 — 0. 130 — 0. 231 E Piscium .... 7 41 49. 914 — 0. 310 +0. 119 +0. 022 — 0. 116 44 Cephei, H. . . 7 47 25. 664 — 0. 850 +0-351 —0. 454 -0. 608 T Piscium . . . 7 50 12.273 -0.357 +0. 149 — 0. 019 -u. 132 / Piscium . . . 7 56 43- 430 — 0. 302 +0. 134 +0. 029 -0. 115 V Piscium .... 7 58 1.243 -0. 350 +0. 157 —0.013 — 0. 129 6" Ceti 7 I 3 7-53" - -0. 280 +0. 131 +0. 048 — 0. 116 V Piscium . . W. 7 I 10 II. 833 -0. 324 +0. 161 +0. 009 - 0. 119 TT Piscium .... E. 7 I IS 51.477 +0.318 — 0. 019 +0. 035 -f 0.077 43 Cassiop. . . 7 I 18 48. 100 +0. 554 — 0. 054 -0.459 +0. 196 Piscium . . . 7 I 24 10. 600 +0.312 — 0. 050 +0. 047 +0, 076 f Ceti 7 ' 30 37- 336 +0. 276 — 0. 064 +0. 124 +0. 076 7 Arietis . . . 7 I 32 5. 126 +0. 333 — 0. 084 + 0.005 +0. 079 50 Ca.ssiop 7 I 38 39- 571 +0. 623 — 0. 204 — 0. 604 + 0.241 a Arietis 7 J 45 33-894 +0. 341 — 0. 141 — 0. 014 + 0.081 e Ceti E. 7 I 51 45-790 +0.312 — 0. 151 +0. 048 +0. 076 -0. 048 40. 147 50 3.669 +0 I5[23-522] —0. 040 49- 589 57 13.241 23-652 —0. 064 -0. 033 24, 070 I 2 47. 768 [23-698] —0. 030 11,884 I 5 35-404 23-520 +0. 068 —0. 022 43- '54 I 12 6-743 23.589 — 0. 001 —0. 020 0.888 ' 13 24.511 23.623 -0.03s —0.014 7.300 1 18 30. 831 23-531 +0. 057 —0. 006 11-554 I 25 35-171 +0 15 23.617 — 0. 029 +0. 001 51.889 I 31 15-377 +0 15 23.488 + 0. 100 +0. 005 48. 342 I 34 11.871 [23- 529] +0. Oil 10. 996 I 39 34-517 23,521 +0. 067 +0.019 37.761 I 46 ■•371 23. 604 —0.016 +0. 020 5-479 I 47 29. 082 23. 603 -0.015 +0. 028 39-655 I 54 3.276 [23. 621] +0. 037 34- 198 2 57-874 23.676 —0. 088 + 0. 044 46. 119 2 7 9-752 +0 15 23-633 -0. 045 NORMAL EQUATIONS, o = — o. 023 + 2. 545 (/<•;' + \.<)Oil dc + 0.044 +2.459rfrt" — i.692(A+ 0.082a'/, — 0.258+ 1.997 (/o' — 1.69^ (/(2" + 20. 226 (/c— o. o54n'/ I + 0.013 — O. 079 da' + o. 082 da" — o. 054 dc +12, 900 dt j a/ = + oMoo (circle west); u'' = + o».238 (circle east); f = o«.095 (+ with circle east). Chronometer No. 1295, at i'> i5'".o chron. time, oh 15™ 23^.588 -^ o».oi2 .slow, losing o».o72 per hour. Assuming a' ^ -\- o. 100 -\- da' circle W. a" = + o. 247 + da" " E. c = + 0.083 + ^/^ " E. AT = + oh IS™ 23'.587 + dt. o. 079 dt ^ whence da' = I da" = dc = dt = 0.000 — o. 009 + 0.012 — o. 001 54 TELEGRAPHIC DETERMINATION OF LONGITUDES Transits of stars observed at Santo Domingo City, by Lieut. J. A. Norris, U. S. Navy, with transit Ahi. 1503, to determine the correction of sidereal c/ironometer Xc\i;-lts No. I2Q^. Date. Name of St; y Ceti . H Circle. Transit over mean of threads. Flexure and in- equality of pivots. s. +0. 304 Level. s. +0. 037 Azimuth. s. — 0. 033 Aberra- tion and coUi- mation. Rate. Seconds of corr. transit. R. A. Chronometer correction. V. 1890. Jan. I /?. w. s. 2 7 54.446 s. +0- 305 J. — 0. 039 s. 55-020 ft. m. s. 2 37 35- 654 h. +0 111. s. 29 40. 634 s. -0. 057 T Celi . . . 2 911. 869 +0. 273 +0. 038 — 0. 069 +o.3>5 — 0. 039 12.387 2 38 52- 946 40. 559 +0. 018 a Arietis . 2 15 43- 536 +o- 325 -l-o. 078 — u. 009 +o-3'5 -0. 035 44.210 2 45 24. 805 40. 595 — 0, oiS 47 Cephei, H. 2 21 46. 986 -1-0. 811 +0. 273 +0.565 + 1-596 — 0. 032 5°. 199 2 51 30.657 [40. 458] 9 H. Camelop 3 18 3.900 +0.477 4-0-185 -1-0.171 -Lu. 625 — 0. 002 5-356 3 47 45- 992 [40. 636] . . . ; Eridani . 3 23 12.789 +0. 274 -|-o. 104 — 0. 068 + 0.314 -l-o.ooi 13-414 3 52 53-978 40. 564 +0. 013 X Tauri . . 3 24 53. 806 -1-0. 320 -|-0. 121 - 0. 014 +0.312 -f 0. 002 54- 547 3 54 35- 086 40. 539 +0. 038 V Tauri . . E. 3 27 36-987 +0. 309 -|-o. 116 -u. 027 +0. 307 -|-o. 003 37- 695 3 57 18. 266 +0 29 40.571 -f 0. 006 y Tauri . . . W. 3 43 51- 937 — 0. 326 +0. 114 —0. 009 -0. 358 -|-0. 012 51-370 4 13 32-018 +0 29 40. 648 — 0.071 (5 Tauri . . 3 46 55- 366 ^0. 330 +0. 149 —0. 003 — 0. 361 -|-o. 014 54. 835 4 16 35-459 40. 624 — 0. 047 f Tauri . . 3 52 31-500 0-333 -fO. 211 -f 0. 001 — 0. 365 -f 0. 016 31.030 4 22 II. 621 40. 591 — 0. 014 a Tauri . . 3 59 56-476 0.328 fo. 269 —0. 006 — 0. 359 -|-o. 020 56. 072 4 29 36. 576 40. 504 +0. 073 I' Eridani . 4 I 9- 333 -0.293 +0. 245 — 0. 058 — 0. 346 -fo. 021 8. 902 4 30 49- 459 40. 557 +0. 020 T Tauri . 4 5 58.474 —0.341 -f 0. 308 -|-o. 012 — 0. 374 -f 0. 024 58. 103 4 35 38. 639 40. 536 +0. 041 a Camelop. 4 13 27.823 — 0. 524 +0. 500 -1-0. 280 -0. 854 -fo. 028 27- 253 4 43 7- 823 [40. 570] 10 Camelop. w. 4 23 58.714 — 0. 473 +0. 434 -fo. 206 — 0. 696 +0. 033 58.218 4 53 38. 798 +0 29[40. 580] Assuming a' = — O. lig-{- da' circle E. «" = — o. 148 -!- 29'n 40».576 -|- dt. f = NORMAL EQUATIONS. :-|-o. 015 -)-2. 655 rfa' — 0.9590^-1- o.g2e, dt' -|- 0.006 -|- I. 755 (/a" -|- I.868(/ir — 0.611 dt — o. 038 — o. 959 rfff' -|- 1 . 868 da" -f 19. 595 (/e — o. 438 dt — o. 020 ~fo. 925 da' — o. 611 da" — 0.4381/1: -f- 13. 115 a? whence da' =^ — o. 005 da" ^ — o. 005 dc = -f- o. 002 dt = -j- o. 002 3'=r — 08.124 (circle east); a" :^ — 0».I53 (circle west) ; c = o'.325 (-)- with circle east). Chronometer No. 1295, at 3I' 21 '".6 chron. time, o'' 29™ 40«.577 -[- o'.ooB slow, losing 0".032 per hour. Jan. 2 11 Tauri 0' Eridani y Tauri . 6 Tauri . e Tauri . . a Tauri . Gr. 848 . . n Camelop. 10 Camelop. I Tauri . . . 1 1 Orionis . . 19 H. Camelop. /? Orionis . . T Orionis . y Orionis <5 Orionis . . E. E. W. _ W. 7 3 27 3 36 3 43 3 46 3 52 3 59 4 4 4 13 4 23 4 26 4 28 4 34 39 4 42 4 49 4 56 36. 036 +0. 309 — 0. 004 -|-o. 008 +0. 366 -.U.037 36.678 47- 679 -l-o. 286 —0.013 -fo. 017 +0. 367 — 0. 029 48. 307 49- 703 +0. 326 — 0. 022 -|-o. 002 +0. 377 — u. 024 50. 362 53- 223 f 0.330 — 0. 025 -\-o. 001 +0. 381 —0.021 53. 889 29. 284 f 0. 333 — 0. 033 0. 000 +0. 385 — u. 016 29. 953 54- 263 +0. 328 — 0. 041 -j-o. 002 +0.379 — 0. 010 54.921 20. 721 -|-o. 692 — 0. 094 — 0. 130 + 1.478 — 0. 007 22. 660 25- 179 +0. 524 — 0. 088 —0. 069 -fo. 900 +0. 001 26.447 58.057 — 0. 473 — 0. 126 +0. 433 -0.815 -fu. 009 57.085 50. 610 -0. 338 —0. 085 +0.018 -0.434 +0. 012 49- 783 36-417 — 0. 326 -0.079 — 0.019 -0.419 +0.013 35-587 49. 586 —0.816 -0. 171 + 1.486 —2. 138 + 0.018 47.965 34- 684 — 0. 284 -0.052 — 0. 147 -0. 408 + 0. 022 33.815 35- 366 — 0. 286 —0. 048 -0.139 — 0. 407 +0. 024 34.510 33- 273 — 0. 310 — 0. 041 -0. 068 — 0. 406 +0. 030 32.478 42. 676 — -0. 298 — 0. 028 — 0. 104 — 0. 404 + 0. 036 41.878 3 57 4 6 4 13 4 16 4 22 4 29 4 34 4 43 4 53 4 56 4 58 5 4 5 9 5 12 5 '9 5 26 18 262 29 849 32 016 35 458 ri 620 36 574 4.510 7 813 38 794 31 361 17 124 29.473 IS 391 16 214 14. 050 23 486 +0 29 41 584 41 542 41 654 41 569 41 667 41 653 [41 850] +0 29[4i 366] +0 29[4i 709] 41 578 41 537 [41 508} 41 576 41 704 41 572 +0 29 41 608 +0. 020 -|-o. 062 — o 050 + 0. 035 — o. 063 -o. 049 +0. 026 +0. 067 -I o. 028 — O. 100 +0. 032 — 0.004 Assuming a' = f o. 069 + da' circle E. f o : rt'/ = — 0.351 +«'«" " W c = + o. 402 + dc " E. /^T = + o'" 29"" 4l».6o5 + dt. ^= + o».o38 (circle east NORMAL EQUATIONS. : + O. 041 + 2. 530 da' — 2. lOI dc — o. 144 dt — 0.055 +^.753«'«"+ 1.3460'^+ o.i'j2dt + 0.246 — 2. loi ^rt' + I. 346 rfrt" + 19. 863 a'c+ 0.061 dt I + o. 002 — O. 144 da' + o. 572 (ta" + o. 061 rf5 313 215] 195 329 268 184 255 377] 258 +0. 064 +0. 092 — o. 087 o. 059 — o. 057 -|-o. 061 -0. 073 — 0.012 -|-o. 072 -f-o. 001 Assuming a' AT : + o. 127 -[- rfa' circle E. : — o. 179 + r/fl" " W. : -f o. 308 + dc " E. : + Ol'29'n 455.254+0'/. NORMAL EQUATIONS, f o = -(-o. io6-|- 2. 5o3(/«' — i.445fl!(r + — 0.080 -f- 2. 944 (/«''' -)- 2.i62dC'\- — o. 106 — 1. 445 (/a' -|- 2. 162 da'' + 18. g2()de — — o. 002 -)- o. 072 da' -|- o. 239 da" — O. 484 dc ~\- 072 dt \ whence da' = — 043 239 dt da" ^ + 028 4.S4 dt dc ^= — 001 I 779 dt) dt = 000 n' := -f 0S.084 (circle east); a" = — 0^.151 (circle west); c = 0^.307 (-|- with circle east). Chronometer No. 1295, at i'" 52"". 2 chron. time, o'> 29™ 45^.256 + o''.oi3 slow, losing o".o64 per hour. Jan. 6 u. Tauri W. Gr.848 .... \i Eridani .... ;■ Tauri ir" Orionis . . 10 Camelop. i Tauri 1 1 Orionis .... W. 19 H. Camelop. . . E. 7 Orionis . . . 17 Camelop. . (5 Orionis .... ■ — 0. 174 — 0. 018 +0. 420 -0. 035 45.809 3 8 34. 409 48. 600 +0. 001 Tauri . . . . 2 49 4. 164 +0-314 — 0. 184 -)-o. 076 +0. 397 — 0. 020 4-747 3 '8 53- 374 48. 627 — 0. 026 2 H. Camelop. . . 2 so 20. 793 +0. 469 — 0. 278 -0. S73 +0. 776 — 0. 018 21. 169 3 20 9.885 [48. 716] . . . f Tauri E. 2 SI 23.013 +0. 3«S — 0. 190 +0.071 +0. 398 — 0. 017 23- 590 3 21 12.237 +0 29 48. 647 — 0. 046 Gr. 716 . . . W. 3 2 50. 564 -0. S02 +0. 097 -0,715 — 0. 949 0. 000 48. 495 3 32 37- 029 +0 29[48. 534] y Camelop. H. . . 3 9 0.043 — 0. s88 +0. 172 — I. 158 — 1.329 [-0. 009 57- 149 3 38 45- 844 [48.695] . . . 1 Tauri . . . . 3 II 8. 6s I — 0. 343 +0. 109 — 0. 048 -0. 473 -f 0. 012 7.908 3 40 56- 556 48. 648 — 0. 047 27 Tauri . . . . 3 12 49.216 -0. 343 +0. 119 — 0. 048 -0. 473 +0.01S 48. 486 3 42 37- 129 48. 643 — 0. 042 ) Eridani . . . . 3 23 SS8i — 0. 274 +0. 136 -\-o. 261 —0. 446 +0. 030 5.288 3 52 53- 936 48. 648 — 0. 047 / Tauri 3 24 47.016 — 0. 320 +0. 167 +0. 053 —0.443 +"• 033 46. 506 3 54 35-058 48. 552 +0. 049 f Tauri . . . . 3 27 30. 101 -0. 309 +0. 175 -|-o. 104 -0. 435 -to. 037 29. 673 3 57 18. 238 48. 565 +0. 036 A Tauri . . . . \V. 3 28 23.S03 — 0. 339 -|-o. 196 — 0. 029 — 0. 466 +0. 038 22. 903 3 58 11.463 —0 29 48. 560 +0. 041 NORMAL EQUATIONS. Assuming a' =: -|- 0. 425 H - da' circle E. f = — 0. 077 -|- 2. 22 3 da' — 2. 131 dc — 0. 306 dt '\ vi'hence da' = + 0.017 «" = + 0. 457- -da" " W. J —0.006 -\- 2. ^02 da" -\- 1.951 rt?^— 0. 366 a'/ 1 da" = + 0.018 c =-fo. 431 H ^dc " E. ) + 0.34 7 — 2.13 I da' -{■ I 95ia'«" ■f 18.890 dc— I. 344 a"^ 1 dc ^ — 0.018 /\T = + o'' 29m 48».6o5 + dt. + o. 008 — o. 306 fl'a' — o. 366 (&" — 1.3440'^ + 12. on aV J dt = — 0.002 a' ^ + o".442 (circle east) ; a"^ + o=.47S (circle west) ; =^ + o. 845 + a'a' circle E. f = -I-0.040 + 2. 864fl'a' — \.(>Tf)dc^ 0.462a'/ ~\ whence a" = + o. 692 + a'a" " W. I —0.021 -\- 4. 102 da" -\- l.220dc-\- 1.419a'/ I c ^ + o.372-fo'f " E. ] _|_o.o76 — i. 636(/a' + i. 22oa'a''' 4- 20. I99a''3o'n7=.4i7 + a'/. [ +0. 006 + 0. 462 0^' + 1. 41 9 (fa'/ + o. 643 a'.r + 1 2. 405 rf/ J a' = + o".828 (circle east); a" = + 08.699 (circle wrest); ,: =: o'.366 (+ with circle east). Chronometer No. 1295, at 5'' 43"" .4 chron. time, oii 30™ 7=.4l8 + 0^.006 slow, losing o».o64 per hour. s da' = 017 da" = + 0. 007 dc = — 006 dt ■= 000 Jan. 21 y Tauri . . A Tauri . . E Tauri a Tauri . . V Eridani . Gr. 848 fi Eridani . .1 Camelop. n Orionis . 130 Tauri . . K Orionis a Orionis Lai. 1 1 382 66 Orionis 36 Camelop. 22 Camelop. E. E. W. W. 3 43 22.231 +0. 326 +0- 079 3 46 25. 693 +0- 330 +0- 063 3 52 1.856 +0- 333 +0. 030 3 59 26. 791 +0. 328 —0.017 4 39. 691 +0. 293 —0. 028 4 3 54-436 +0. 692 —0. 092 4 9 50-487 +0. 293 —0. 070 4 12 58.414 -l-u. 524 —0. 152 5 3 S-27? — 0. 294 — 0. 035 5 10 53.440 -"■331 — 0. 004 5 12 24. 205 — 0. 282 +0- 003 5 '9 4-914 —0.312 +0. 032 5 24 25. 006 -0. 293 +0.051 5 29 1-569 — 0. 306 +0.071 5 3> 41-843 — 0. 520 +0. 140 5 36 39. 186 — 0. 564 +0. 190 0.031 o. 012 o. 004 o. 022 o. 210 1.905 0. 209 1. 020 0.257 o. on 0.342 o. 139 o. 262 0.177 1.275 1.572 +0.415 +0. 419 +0. 423 +0.417 +0. 401 + 1. 624 +0. 401 +0. 990 — o. 440 — o. 462 -o. 447 — o. 444 — o. 440 —0.441 — 1. 071 —1.248 — 0. 056 23. 026 — o. 053 26. 464 -0. 047 2.591 —0. 039 27. 502 -0. 037 40. 530 —0. 034 54.721 —0. 028 51.292 —0. 025 58. 73> +0. 029 4.794 +0. 037 52.691 +0. 039 23.861 +0. 046 4-375 +0. 052 24. 638 +0. 057 I. 127 +0. 059 39-J76 +u. 065 36.057 4 13 4 16 4 22 4 29 4 30 4 34 4 40 4 43 5 33 5 41 5 42 5 49 5 54 5 59 6 I 6 6 31.890 35- 338 11.503 36. 473 49. 340 3-756 0.179 7-456 13.681 J-S75 32.712 13- 273 33- 522 10. on 48. 158 44.812 +0 30 +0 30 +0 30 -o 30 8 864 8 874 8 912 8 971 8 811 [9 035] 8 887 [8 725] 8 887 8 884 8 851 8 898 8 884 S 884 [8 982] [8 755] +0. 020 +0.010 — o. 028 — 0.087 +0. 073 — 0.003 0.003 0.000 +0- 033 — o. 014 0.000 0.000 Assuming NORMAL EQUATIONS + 0.571+ (/a' circle E. f 0= + o. 020 + 2. 574 a'a' : + o. 70s + da" " W. I — 2. 007 dc — o. 048 dt ^ whence da' = + 2. 591 a'a"+ o. 968a' 30m 108.398 -j-os.014 slow, losing oi'.o6o per hour. : + 1 . 360 + da' circle E. ■.+ 1.303 + da" " W. = + 0.351+^^ " E. : — oh 30™ iC.jgS + dt. whence da' = — 031 da" = + 028 dc = + 013 dt = — 006 Jan. 23 a Tauri . V Eridani Gr. 848 r Tauri . Ii Eridani a Camelop. i Tauri . . TT^ Orionis 1 1 Orionis /3 Eridani . . 19 H. Camelop. 22 Camelop. . 5 Monocerotis 8 Monocerotis y Geminorum . .y Monocerotis E. 7 7 7 7 7 7 7 E. 7 W. 7 7 7 7 ^ 7 7 W. 7 3 59 23, 883 +0. 328 — 0. 01 1 +0. 039 +0- 358 — 0. 046 24-551 4 36. 679 +0. 293 — 0. 010 +0. 362 +0. 345 -0. 045 37- 624 4 3 52.893 +0. 692 — 0. 024 —3- 291 + 1-397 — 0. 041 51.626 4 5 26. 104 +0. 341 —0.012 — 0. 078 +0. 373 -0. 040 26. 688 4 9 47-454 +0. 293 — 0. 010 +0.361 +0- 345 —0. 036 48. 407 4 12 56.4:4 +0. 524 —0.018 —I. 762 +0.851 -0. 033 55-976 4 14 43- 844 +0. 332 —0.012 — 0. 003 +0- 363 —0.031 44- 493 4 18 18.674 +0. 303 — 0. on +0. 269 +0. 344 — 0. 028 19.551 4 28 5. 794 — 0. 326 +0. 202 +0. 054 -0. 398 — 0. 018 5-308 4 32 14-996 — 0. 290 -f 0. 223 +0. 373 -0. 386 — 0. 014 14. 902 4 34 22.557 —0.816 +0. 689 -4- 263 —2. 032 — 0.012 16.123 5 36 37- 300 — 0. 564 —0. 272 -2. 035 —1.089 -|-o. 048 33- 388 5 39 18.404 — 0. 288 -0. 139 +0. 388 -0. 386 +0.051 18. 030 5 47 45. 486 -0. 307 — 0. 148 +0. 222 -0. 385 +0. 058 44. 926 6 I 10.851 -0. 328 — 0. 158 +0.032 —0. 401 +0. 072 10. 068 6 4 44. 474 — 0. 316 — 0. 153 +0. 138 -0. 390 +0. 075 43- 828 4 29 36.455 4 30 49- 322 4 34 3-646 4 35 38. 520 4 40 o. 163 4 43 7-400 4 44 56- 349 4 48 31.360 4 58 17.048 5 2 26.688 4 28. 564 6 44. 780 9 29. 856 17 56.755 6 31 21. 821 6 34 55.618 +0 30 11.904 1 1 . 698 [12. 020] 11.832 11.756 [11.424] 11.856 +0 30 11.809 +0 30 11.740 11.786 [12.441] [11.392] 11.826 II. 829 '1-753 +0 30 11.790 -o. 106 -0. 100 -o. 034 +0. 042 — o. 058 — o. 01 1 +0. 058 +0.012 — o. 028 —0.031 +0. 045 +0.008 NORMAL EQUATIONS. = + o. 026 -f 2.656 (/a' — t.8g2 dc+ 0.0770'/ + 0.120 +2. gSs da" + I.'j'j2dc+ o. ^g6 dt + o. 272 — 1.892 da' + I. 772 da" + 19. 966 dc + o. 246 ■*■ + o. 076 + 0.077 '*''''' + o. 496 da" + o. 246 dc + 12. 687 dt a' = +.OB.964 (circle east); a" = + o«.924 (circle west); c — 08.364 ( + with circle east). Chronometer No. 1295, at 4I' 46m 8 chron. time, o'' 30'" ii«,798 -J- o'.oii slow, losing o».os8 per hour. Assuming a' = + o. 983 + da' circle E. a" — + o. 956 + da" " W. c = + O. 377 + dc " E. /\T = + o"! 30"! 1 1».793 + dt. whence da' — s — 0. 019 da" = — 032 dc = — 013 dt == — 0. 004 60 TELEGRAPHIC DETERMINATION OP LONGITUDES Transits of stars observed at Santo Domingo City, by Lieut. J. A. Norris, U. S. Navy, with transit No. 1503, to determine the correction of sidereal chronometer Negus No. i2i)S- Date. 1890. Jail. 24 Name of Star. a Tauri . vr'' Oiionis 10 Camelop. ( Tauri . 1 1 Orionis /? Eridani 19 H. Camelop. T Orionis 17 Camelop. Groom. 966 circle W a" = 4- 1. 496 4- da" " E. c =4-0.303 4- dc " E. ^T =+ oi> 30™ 14^641 -j- A NORMAL EQUATIONS. - o. 020 -j- 2. 441 da' -\- 2. 470 dc — o. 503 dt " I — 0.013 4" ^- 099 '^3''' - o.ig4dc-\- l.lS;idt I — o. 176 -f- 2. 47oa'a' — o. I94(&''' -|- 18. 421 rfc — 0.9251/1? 1^ -f-o.03i — o. 5o38 43.573 +0,312 — 0. 183 + 0.273 +0- 303 —0,021 44- 257 5 49 13- 150 28, 893 -0.035 Lai. 1 1382 . 7 5 24 3. 661 +0. 293 — 0. 1 96 + o-5'7 +0, 301 —0.016 4,560 5 54 33-381 28, 821 +0, 037 66 Orionis . . 7 5 28 40. 276 +0. 306 —0. 225 + 0-349 +0, 302 —0.012 40, 996 5 59 9.876 28, 880 — 0, 022 36 Camelop. . 7 5 31 20.643 +0. 520 — 0. 401 — 2.515 +0.733 — 0, 009 18,971 6 I 47.782 [28,811] . . . 22 Camelop. . 7 5 36 17-757 +0. 564 —0. 480 — 3. 102 +0. 854 — 0, 004 15-589 6 6 44-413 [28. 824] 71 Geminorum E. 7 5 37 45- 237 +0. 340 — 0, 296 — 0, 108 +0. 326 — 0.003 45- 496 6 8 14.529 +0 30 29, 033 -0. 175 ft (ieminorum W, 7 5 45 50- 553 —0. 340 0.000 — 0. 107 — 0, 369 +0. 005 49- 742 6, 16 18, 639 +0 30 28.897 — 0. 039 8 Monocerotis 7 5 47 28.113 — 0. 307 +0. 003 + 0-331 — 0. 342 +0, 006 27, 804 6 17 56.675 28.871 — 0. 013 a Argus . . . 7 5 SI 1-493 — 0. 16S +0. 006 + 2.148 -0, 562 +0.010 2,927 6 21 32. 004 [29.077; . . . 23 H. Camelop, 7 5 57 10,964 — 0. 848 +0. 067 — 6.741 —1,904 +0,016 1-554 6, 27 30, 426 [28.872] y Geminorum 7 6 53-510 -0. 328 +0. 034 + 0.048 -0, 356 +0, 019 52-927 6 31 21,767 28. 840 +0.018 5 Monocerotis 7 6 4 27. 151 -0.316 +0. 042 + 0. 205 -0. 346 +0, 022 26, 758 6 34 55-554 28. 796 +0. 062 f Geminorum • 7 6 8 38. 974 — 0. 322 +0. 052 + 0.134 -0. 350 +0. 026 38,514 6 39 7-273 28.759 +0. 099 18 Monocerotis 7 6 II 39.281 - 0. 303 +0, 056 + 0,378 — 0, 341 +0. 029 39. 100 642 7,904 28. 804 +0. 054 24 H. Camelop, . . W. 7 6 13 41.986 -0. 735 +0. 142 — 5.278 — 1,529 +0,031 34-617 6 44 3- 837 +0 3o[29. 220] NORMAL EQUATIONS, o = + o, 007 + 2. 467 (/a' — 1. 411 dc-\- o. 221 dt — o. 210 +4. 397 da" + o, 636 dc + o. 881 dt + 0. 280— i.4ll(&'+o. 636 da" + 21. S37 dc— o. 349 dt — o, 162 + o, 221 da'-\- o. 881 da" — o. 349 dc + 13. 209 dt «' = + I". 408 (circle east); a" = + l», 378 (circle west); ,r = o», 321 (+ with circle east). Chronometer No. 1295, at 5" 40"".9 chron, time, oh 30'^ 28",858 -^ o=,0I4 slow, losing o».oS7 per hour. Assuming a' =-{- 1.420 -{- da' circle E, a"=+ I. 330 + da" " W, c =+0, 336 + a'i- " E, /^T = — o" 3oni 28^,859 + dt. whence da' = — o. 012 da" = + o. 048 dc = — o, 015 dt =: + o. 009 62 TELEGRAPHIC DETERMINATION OF LONGITUDES Transits of stars observed at Santo Domingo City, by Lieut. J. A. Norris, U. S. Navy, with transit No. 1503, to determine the correction of sidereal chronometer Negus No. I2gj. Date. Name of Star. G vi t .£ •+- 6 12, Transit over mean of threads Flexure and in- equality of pivots. Level. Azimuth. s. -2. 123 Aberra- tion and colli- niation. Rate. -V. —0. 036 Seconds of corr. transit. R. A. Chronometer correction. V. 1890. Feb. 8 17 Camelop. . . w. 4 h. m. i. 4 49 20. 108 0. —0. 494 0. +0.013 .r. -0. 753 s. 16.715 h. in. s. 5 '9 47-215 h. m. s. +0 3o[30- 500] J. 6 Ononis . . . 7 4 55 53-324 — 0. 298 -|-o. 012 +0. 444 — 0. 342 — 0. 031 53- 109 5 26 23.290 30. 181 +0. 056 (p^ Ononis . . . 7 4 S8 17.243 —0.316 +0.014 +U.219 -0. 347 — 0. 029 16.784 5 28 46. 935 30. 151 +0. 086 C Taiiri 7 5 34- 847 -o. 337 +0.016 —0. 066 ~o. 367 —0. 027 34- 066 5 31 4.280 30. 214 +0. 023 (! Doradus . . . 6 5 14 3- 792 — 0. 077 +0. 005 +3- 338 -0. 834 —0.016 6.208 5 44 36. 700 [30- 492] . . . n Orionis .... 7 S 18 43- 287 -0.312 +0. 020 +0. 267 -0. 345 — 0.012 42. 905 5 49 '3- 140 30. 23s +0. 002 Lai. 1 1382 . . . 7 5 24 3.261 — 0. 293 +0.017 +0. 505 -0. 342 — 0. 007 3.141 5 54 33- 364 30. 223 +0. 014 V Orionis . . . 6 5 30 48.115 — 0. 325 +0.015 +0.091 — o. 354 — 0. 002 47- 540 6 I 17.740 30. 200 +0. 037 22 Camelop. . . w. 7 5 36 18. 657 — 0. 564 +0. 020 -3- 030 -0. 970 +0. 003 14. 116 6 6 44. 380 +0 30[30. 264] 5 Monocerotis E. 7 5 38 58.450 -1-0. 288 — 0. 194 +0. 580 -f 0. 304 +0. 005 59- 433 6 9 29. 724 4-0 30 30. 291 — 0. 054 M Geminorum 7 5 45 47-979 +0. 340 -0. 239 — 0. 108 +0. 327 -|-u. on 48. 310 6 16 18. 630 30. 320 — 0. 083 8 Monocerotis . 7 5 47 25.647 +0. 307 -0.217 +0-332 +0. 303 -l-o. 012 26. 384 6 17 56.667 30. 283 — 0. 046 a Argus . ... 1 5 5° 59- "29 +0. 1 68 —0. 122 + ^-155 +0. 498 +0.01S 61.843 6 21 31. 980 [30. 137] 23 H. Camelop. . 7 5 57 5.064 +0. 848 —0. 632 -6. 761 + 1.686 -|-o. 020 0. 225 6 27 30.362 [30- 137] y Geminorum . . 7 6 51.014 +0. 328 — 0. 250 +0. 048 +0. 315 +0. 023 51-478 6 31 21. 760 30. 282 — 0. 045 S Monocerotis 7 6 4 24. 703 +0.316 —0. 244 4-0. 206 +0.307 -|-o. 026 25-3'4 6 34 55-546 30. 232 +0. 005 f Geminorum . 7 6 8 36. 494 +0. 322 —0. 254 +0. 134 +0.310 +0. 030 37- 036 6 39 7. 266 30. 230 +0.007 43 Camelop. . E. 7 6 II 23.779 +0. 558 —0. 445 -2. 978 +0. 843 +0. 032 21.789 6 41 52.000 +0 3o[3o.2n] Assuming a' ^ -f" i . 340 + i/rt' circle W. (o «'/ = + 1.440-l-a'a" " E. J c =-fo. 348 + arf " E. \ AT = + oi>30'n30».236 + ^^. [ a' ■= + l».376 (circle Chronometer No. 1295, at NORMAL EQUATIONS, o. 146 -|- 3. 656(!!'a'' — 0.357 at -f- 0.809 a'/"! whence ;/«' -f 0.228 -\- ^.\/^\da" — o.2Q\dc-\- o.go(>dt I da" + 0.595 — o.357a'a' — o. 204 (/«"+ 22. 582^1: -|- o.o\2dt ( dc — u. 067 + o. 809 ofa' + o. 906 rfa" + o. 0120^ + 13. 6030'/ J dt west); a" = + l".382 (circle east) ; <: = o^. 322 (-f with circle east), jh 32"!. 9 chron. time, o'' 30™ 308.327 + os.oioslow, losing o».o5o per hour. = + o. 036 = ^ o. 058 = — u. 026 = + o. 007 Feb. 9 17 Camelop. . Groom. g66 cp^ Orionis . S' Orionis . Sf- Orionis . f Tauri . . (T Orionis [30 Tauri (S Doradus . a Orionis . Lai. 1 1 382 66 Orionis . 36 Camelop. 22 Camelop. ri Geminorum y. Geminorum 8 Monocerotis a Argus . E. • E. W. W. 4 49 17-493 4 54 34- 586 4 58 15. 069 4 59 20. 126 4 59 26. 619 5 o 32. 709 5 2 41-473 5 lo 29. 754 5 14 I- 314 5 18 42. 291 5 24 2. 306 5 28 38. 893 5 31 20.521 5 36 17.993 5 37 44.021 5 45 48. 237 5 47 25.661 5 50 58. 636 +0. 494 — 0- 370 —2. 191 +0. 612 — 0. 024 16. 014 +0.671 —0.541 -4- 568 + '-072 — 0. 019 31. 201 +0.316 —0. 267 +0. 226 +0. 282 - 0. oi6 15. 610 +u. 289 — 0. 248 +0- 579 +0. 279 — 0.015 21. 010 +0. 289 — 0. 248 +0. 579 +0. 279 — 0.015 27- 503 +0. 337 — 0. 292 — 0. 068 +0. 298 — 0.014 32. 970 +0. 294 — 0. 262 +0.51 1 +0. 278 —0.013 42. 281 +0.331 — 0. 323 +0. 021 +0. 292 —0. 006 30. 069 +0. 077 — 0. 078 +3- 445 +0.678 — 0. 003 5-433 —0.31 1 — 0. 102 +0. 308 — 0. 321 +0. 001 41.866 -0. 293 — 0. 083 +0. 583 —0.318 +0. 006 2. 201 — u. 306 — u. 074 +0. 394 — 0. 319 +0. 009 38- 597 —0. 520 — 0. 114 —2. 838 — 0. 774 +0. on 16. 286 -0. 564 —0. 098 - 3- 499 — 0. 902 +0.015 12. 945 —0. 340 — 0. 055 — 0. 122 — 0. 344 +0.017 43- 177 —0. 340 — 0. 031 — 0. 124 -0.344 +0. 023 47.421 -0. 307 — 0, 024 +0. 38 1 -0. 319 +0. 025 25.417 -0. 168 —0. 008 +^-477 — 0. 524 +0. 028 60. 44 1 5 19 47- 5 25 2. 5 28 46. 5 29 52. 5 29 58. 5 31 4- 5 33 13- 5 41 I- 5 44 36- 5 49 '3- 5 54 33- 5 59 9. 6 I 47- 6 44- 8 14. 6 18. 7 56- 31- 6 6 6 6 6 2 184 589 921 310 891 268 513 423 650 129 348 856 702 344 5" 621 658 955 +0 +0 +0 +0 3o[3i- [31- 31- 31- 31- 31- 31. 31" 3o[3i- 30 3'- 31- 31. [31. [31. 3«- 31- 3'- 3o[3i- 170] 3S8] 3" 300 388 298 232 354 217] 263 147 259 416] 399] 334 200 241 514] o. 034 — o. 023 — O. 1 1 1 O. 021 +0. 045 o. 077 +0. 014 +0. 130 +0.018 o. 057 +0. 077 +0. 036 Assuming a' = + 1 . 440 -\- da' circle E. a" = + 1 . 530 + da" " \V. c ^ + o. 327 + de " E. ^T ;= + 0''30'n3I^ 279 + a'jf NORMAL EQUATIONS. + o. 084 + 4. 300 ife' + o.28g dc-\- l.o'jodt^ — 0.207 +3.6i2a'(r"+ o.37iaV+ o.-j2<)dt + 0. 656 + o. 289 a'a' + 0. 371 da" -\-22.S'j6de — o. 3161* (^ — o. 161 + I. o70i/fl' + o. 729a'a" — o. 3161/^+ 13. 805 (// + 1S.420 (circle east); a"^-\- P.530 (circle west); f = 08.298 (+ with circle east). Chronometer No. I295,at5ii i7i".8 chron. time, o" 30'" 318.277 -J- o8.oi3slow,losing 08.050 per hour. ro= I < I whence da' = — o. 020 da" = + o. 059 de =-. — o. 029 dt = + o. OOQ IN MEXICO, CENTEAL AMERICA, THE WEST INDIES,. ETC. 63 Transits of stars observed at Santo Domingo City, by Lieut. /. A. Morris, U. S. Navy, with transit No. 1503,10 determine the correction of sidereal chronometer Negus No. I2gj. Date. Name ^f Star. .a "»- 6 7 Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and coUi- mation. Rate. Seconds of corr. transit. R. A. Chronometer correction. V. 1890. Feb.io 17 Camelop. W. /;./«. s. 4 49 17-900 — 0- 494 J. 0. 000 — z. 114 0. — 0. 792 s. — 0. 108 s. '4- 392 h. m. s. 5 19 47-152 h. m. s. +0 30[32. 760] s. Groom. 966 . . 4 4 54 36.088 —0. 67 1 +0. on —4. 407 — 1.388 — 0. 103 29- 530 5 25 2. 528 [32. 998] a Orionis .... 7 5 2 41. 081 — 0. 294 -|-o. 012 +o- 493 — 0. 360 — 0. 096 40. S36 5 33 13-499 32. 663 +0. 080 V Orionis .... 7 5 30 45- 596 -0. 325 -|-o. 025 -|-o. ogo — 0. 372 —0. 070 44- 944 6 I 17.718 32- 774 —0.031 7 Geminorum . . 5 5 37 42. 755 — 0. 340 -\-o. 624 -0. 105 — 0. 390 —0. 064 41. 880 6 8 14. 502 32. 622 +0. 121 a • Argus . . . 7 5 50 57-657 — 0. 168 "f 0. 005 +2. 136 — 0. 593 — 0. 052 58. 98s 6 21 31. 929 [32- 944] . . . 10 Monocerotis 4 5 51 59-457 — 0. 290 +0. 007 +0- 540 — 0. 361 —0.051 59- 302 6 22 31. 979 32. 677 4-0. 066 Canis Majoris . 7 6 9 45. 684 — 0. 269 — 0. 022 +0. 821 -0- 375 — 0. 034 45- 80s 6 40 18.658 32. 853 — 0. no 18 Monocerotis w. 7 6 II 35-433 — 0. 303 — 0. 029 +0- 375 —0. 360 — 0. 033 35- 083 6 42 7. 878 +0 30 32. 795 — 0. 052 26 Monocerotis E. 7 7 5 26.301 +0. 283 — 0. 218 -|-o. 614 +0. 324 -|-o. 016 27. 320 7 36 0.040 +0 30 32. 720 +0. 023 3 Urs£e Majoris, H 7 7 31 22.971 +0- 556 — 0. 462 —2. 770 fo. 885 -|-o. 040 21. 220 8 I 53-996 [32- 776] . . . f 1 Cancri 6 7 35 21.606 +0- 331 — 0. 279 -f 0. 010 +0. 336 +0. 044 22. 048 8 5 54. 810 32. 762 — 0. 019 fi Cancri 7 7 40 0. 230 +0.316 — 0. 270 -|-o. 206 +0. 324 +0. 048 0.854 8 10 33. 569 32-715 -|-o. 028 /? Volantis . . . 7 7 53 58- 586 +0. 077 — 0. 068 +3- 155 + 0. 780 -\-o. o6i 62. 591 8 24 35.428 [32. 837] .. HydKE .... 7 8 2 27.681 +0- 305 -0. 277 +0- 330 +0. 321 +0. 069 28. 429 8 33 I- 224 32. 795 -0. 052 f Hydrse 7 8 19 1. 916 +0. 310 — 0. 294 +0- 275 +0- 322 -fo. 084 2. 613 8 49 35- 393 32. 780 — 0. 037 a Cancri 7 8 21 55. 563 +0. 320 — 0. 306 +0- 143 +0. 327 -|-o. 087 S6..134 8 52 28. 894 32. 760 —0.017 (fl Urss Majoris . . E. 7 8 30 13- 629 • +0. 540 — 0. 528 -2- 579 +0. 839 +0- 094 11-995 9 44. 828 +0 3o[32. 833] Assuming a' =: -\- i . 2^0 -\- da' circle. W. «" = + 1.280-i-^a'' " E. c = + o. 327 + dc " E. /\T = + oh 30™ 32".764 -f dt. NORMAL EQUATIONS. -0.531 -I- 3.917 (fo' — 0.5880'^+ i.Sgga"-? -0.082 -\- 4. log da" -\- 0.248^1:+ o. 9i6a'i? - o. 221 — O. 588 da' -\- o. 248 da" -\- 22. 432 dc — o. 085 dt -o. 151 -f I. 5991/3' -|- o. 916 (fa" — 0.085 '^e -\- 13. y^Sdt whence da' = -|- o. 140 a'a" ^ -j" o. 02 1 dc ^ + 0.013 dt = — o. 007 a' = -)- i''.370 (circle west); a" = -{- i°.30i (circle east); c = o'.340 (~|- with circle east). Chronometer No. 1295, at 6'i47'".4 chron. time, o'' 30"' 32«.743 + os.013 slow, losing 0>.O55 per hour. Feb. II e Hydrse . . . p Ursse Majoris e Hydrae . . a Hydrce . . Leonis . . . e Leonis .... y Leonis . . u Leonis .... 32 Ursse Majoris . yi Leonis . . 9 Draconis, H. . 35 H. Ursse Majoris 41 Leonis Minoris / Leonis . . . a Ursse Majoris . ;f Leonis .... (! Leonis .... a Leonis . . . E. W. 8 10 8 22 8 38 851 9 4 9 9 9 30 9 31 9 39 9 43 9 55 10 4 10 6 10 12 10 26 10 28 10 37 10 44 22. 989 +0.311 —0. 090 +0. 179 +0. 361 — 0. 067 23- 683 6. 171 +0. 546 — 0. 166 -1.792 +0- 958 — 0. 058 5-659 4-484 +0- 304 — 0. 107 +0. 238 +0- 358 — 0. 045 5-232 36. 696 +0. 284 — 0. u6 +0. 398 +0. 362 -0- 035 37- 589 42.817 +0.317 — 0. 142 +0. 126 +o- 364 — 0. 025 43- 457 2.647 +0.344 — 0. 157 —0. 098 +0- 393 — 0. 021 3.108 46. 200 +0- 330 -0. 137 +0.018 + 0.375 — 0. 004 46. 782 56. 794 +0. 321 — 0. 131 +0. 093 +0. 367 — 0. 003 57-441 30. 936 +0. 520 -0- 195 —1.567 +0. 868 +0. 002 30- 564 21. 760 — 0. 336 +0. 154 — 0. 029 — 0. 425 +0. 006 21. 130 19. 086 — 0. 708 +0- 344 —2. 850 -1.678 + 0.015 14. 209 43- 100 — 0. 568 +0. 288 -I. 790 —I- 145 -fo. 022 39- 907 53- 457 -0. 342 +0. 175 — 0. 080 — 0- 435 +0. 024 52- 799 55-S13 -0.318 +0. 168 +0. 104 ^-0. 406 +0. 029 55.090 26.314 -0. 489 +0. 273 -I- 193 -0. 857 +0- 039 24. 087 47- 469 -0.313 40.177 +0. 146 — 0. 402 +0. 041 47- "8 42- 574 -0. 337 f 0. 197 — 0. 039 -u. 427 +0. 048 42. 016 54- 674 —0.31 1 +0. i87_ +0. 165 — u. 401 +0. 054 54. 368 8 40 8 52 9 8 9 22 9 35 9 39 10 I 10 2 10 10 10 13 10 25 10 35 10 37 10 43 10 56 10 59 11 8 II IS 57- 708 +0 30 34.025 39- 573 [33 914] 39- 178 33 946 II. 636 34 047 17-446 33 989 37. 170 34 062 20. 894 34 112 31-491 34 050 4-649 +0 3o[34 085] 55- 168 +0 30 34 038 48.516 [34 307] 13- 890 [33 983] 26. 767 33 968 29- 153 34 063 57-973 [33 886] 21. 114 33 996 16. 117 34 lOI 28. 400 fo 30 34 032 +0.008 +0. 087 0.014 +0. 044 -o. 029 -o. 079 -o. 017 -o. 005 +0. 065 o. 030 +0.037 0.068 40. 00 1 NORMAL EQUATIONS. f o = — 0.098 + 2. 300 ifa' — I. 507 n't- + 0.06^ dt J +0.076 + 3- 337 "''i^'^ -f 3-8i4«'f— 1.058^; ] +0 230 — 1.507 (/«' + 3.814 (/«" + 22. 766 a'f+ o.46jdt [^ +0.055 +0.067 (/«'— 1.058 ^a" + o-463<2t+ 14- 2i3(/^ , rt/ = + o»,88o (circle east); a" — + o».799 (circle west); c- = o».378 ( +with circle east) . Chronometer No. 1 295, at 9" 36"',3 chron. time, oh 30™ 34».033 J^ o»,oo9 slpw, losing o=,047 per hour Assuming a' = + o. 844 + da' circle E. a" = + o.SlS + da" " W. c := + o. 382 + dc " E. /^T = + oi'30"'34".035+'*- whence da' = + o. 036 da" = — o. 019 dc = — o. C04 dt = — o, 005 64 TELEGRAPHIC DETEEMINATION OF LONGITUDES Ti-iinsils of stars observed at Santo Domingo City, by Lieut. J. A. Morris, U. S. Na^y, with transit No. 1303, to determine the correction of sidereal chronometer Negus Nil. I2^J. [>ate. Name o( Star. U w. 6 'A Transit over mean of threads. Flexure and in- e(|uality of pivots. J. -0. 340 Level. Azimuth s. —0. 079 .Vberra- tion and colli- mation. Rate. Seconds of corr. transit. s. 37-852 R.A. Chronometer correction. V. 1889. Feb. 13 Ti Geminorum . . . 7 h. f/i. s. 5 37 38-566 s. +0- 139 s. — 0. 344 s. —0. 090 h. 6 ?«. s. 8 14.471 h. m. s. +0 30 36. 619 —0. 102 a Argus 6 5 50 54- 343 — 0. 168 -|-o. 069 + 1-598 -0. 524 -0.077 55-241 6 21 31. 850 [36- 609] ji Canis Minoris . . 6 so 35. 469 —0.314 +0. 134 +0. 179 — 0. 321 —0.018 35- 129 7 21 II. 604 36. 475 -|-o. 042 Piazzi VII, 116 . 6 52 5.510 —0. 279 +0. 119 +0. 520 —0. 324 —0. 017 5-529 7 22 41- 950 36.421 +0. 096 24 Lyncis w. 7 3 8- 750 —0. 464 +0. 202 -I. 290 — 0. 617 —0.006 6-575 7 33 43-094 +0 3o[36. 519] Groom. 1374 , . E. 7 16 28. 657 +0. 652 -0. 157 —2.562 -|-i. 022 -)-o. 007 27.619 7 47 3-811 +0 30[36.i92] 3 Ursa; Majoris, H. 7 31 17-793 +0- 556 — 0. 178 -1-795 +0. 769 -|-o. 022 17.167 8 I 53-965 [36.798] fi Cancri . . . 7 35 17-741 +0-331 —0. : 14 -f-o. 007 +0. 292 +0. 026 18.283 8 5 54- 806 36- 523 — 0. 006 20 Navis 7 37 39-837 +0. 272 —0. 096 +0. 488 +0. 289 +0. 028 40. 818 8 8 17-319 36- SOI +0.016 /3 Cancri . . 7 39 56- 379 +0.316 — 0. u6 +0- 133 +0. 2S2 +0. 030 57. 024 8 10 33-565 36- 541 — 0. 024 30 Monocerotis E. 7 49 33- "4 +0- 293 — 0. 124 +0-317 +0. 279 +0. 040 33-919 8 20 10. 461 +0 30 36. 542 — 0. 025 NORMAL EQUATIONS. Assuming a' = + 0. 818 -f rfa' circle W. f o = — o. 435 + 2. 205 30" 36^.530 + ■*. [ — o. 146 -f 0.877 1/0' + o.2iO(/o"+ o. 479 !'!, dc — O-TJ"] dt + 0.236 +3. 8i7(/(j"+ 4. o43rf,:-p o.6gi dt + o. 470 — 2. 615 da' + 4. 043 da'^ + 18. 686 dc + 2. 017 dt + o. 080 — o. 777 da' + o. 691 da" + 2. 017 dc + 10. 650 dt n' = + l=.899 (circle east); a" = + I'.I96 (circle west) ; r = o».468 (+ wilJi circle east). Chronometer No. 1254, at 4'' 44'". 6 chron. time, i'' 13™ 228.155 -j- 08.015 fast; losing o».047 per hour. whence da' = + 0. on da"=- — o. 083 dc = — 0.014 dt ^ — o. 002 Dec. 29 /? Tiianguli . . 4 Urs. Minoris, S.P, d Arietis 5 Urs. Minoris, S. P. V Arietis 6 Ceti 35 Arietis /i Ceti /3 Urs. Minoris, S.P. 6 Arietis . . . Tauri f Tauri f Tauri .... Gr. 716 . . . . r) Tauri . . . 27 Tauri . . . W. W. E. E. 3 16 3 22 3 25 3 40 3 45 3 47 3 SO 3 52 4 4 4 18 4 32 4 34 4 38 4 45 4 54 4 45 17.256 -0. 331 +0. 069 — 0. 277 — 0. 446 — 0. 040 16. 311 27.877 +0. 172 -0. 034 +4. 172 + 1-779 - 0. 03s 33-831 17- 643 --0. 299 — 0. 058 — 0. 002 — 0. 390 -0. 033 16.861 57- 964 +0. 1 1 1 —0.017 +3- 628 + I-S4I — 0. 020 3-207 51.496 — u. 304 +0. 044 — 0- 037 — 0- 395 — 0. 017 SO- 787 7-759 --0. 267 +0. 037 +0. 288 — 0. 368 — 0. 016 7-433 17.197 -0. 365 +0. 042 — 0. 136 —0.414 — 0.013 16. 3n 17- 103 — 0. 283 +0. 036 +0. 146 — 0. 373 — 0. 012 16. 617 17. 022 +0. 070 +0. 058 +2. 748 — 1-23S — 0, 002 18. 641 36. 060 +0. 300 +0. 240 — 0. OOI +0. 348 +0. 009 36- 956 9-593 +0. 281 +0.228 +0. 135 +0-331 +0.019 10. 587 28. 454 +0. 282 +0. 227 +0. 127 +0- 333 +0. 021 29- 444 3-986 +0.251 +0. 230 + 0. 087 +0- 336 +0. 024 4-914 52. 170 +0. 449 +U.491 — I. 106 +0.719 +0. 030 52-753 12. 636 +0. 308 +0. 243 — 0. 063 +0. 358 +0. 036 13-518 53-213 +0, 308 +0. 243 — 0. 062 +0. 358 +0. 038 54- 098 2 2 56. 041 2 9 13. 686 2 n 56. 689 2 27 42. 446 2 32 30. 529 2 33 47- 302 2 36 56.050 2 38 56. 184 2 50 58.518 3 5 16.767 3 18 50.310 3 21 9. 120 3 24 44- 585 3 32 32.402 3 40 53- 179 3 42 33-729 -I 13 20. 270 [20. 145] 20. 172 [20.751] 20. 258 20. 131 20. 261 -I 13 20.433 -I i3[2o. 123] 20. 189 20. 277 20. 320 20. 329 [20.351] 20. 339 -1 13 20.369 -o. 009 -o. 107 -0.021 -O. 148 -0.018 +0- 154 — 0.090 — 0.002 -|-o. 041 +0.050 +0. 060 +0. 090 NORMAL EQUATIONS. = — o. 150+ I. 501 (/«' + o. 977fl'(r+ o. ic — o. 039 + 1 . 171 da" — 1 . 293 dc — o. 1 34 dt + 0. 907 + 0. <)TJ da' — I. 2g2 da" + 16. 626 at + o. 7080"^ + 0. 237 + 0. igS da' —o. 134 (/rz" + o. 708 (/ Licul. Charles Laird, U. S. Navy, with tiaiuit Mi. fjO./, to Jeterinine the correction of iidercal chronometer Ne^us i\'o. J2J4. Date. isss. Dec. 30 Name of Star. rrt U ■u D ^ A " C Celi . V Arietis ,i Arietis 50 Gissiop. a Arietis ;i Trianguli t) AriL-tls I Cassiop. i^ Ceti . 36 H. Clsm..].. V Arietis (! Ceti . /i Ceti . 41 Arietis. 47 Cepliei, II. a Ceti , /J Persei . jj I'ersei d Arietis \V. Transit over mer,n of threads. h. fu. s, - 59 16. 249 3 o 44- 257 3 I 4S. 203 3 7 17- 143 3 14 12.917 3 i5 14-54(5 3 25 '4-944 3 33 14.450 3 35 33. 253 3 40 52. 221 3 45 50-094 3 47 6. 569 3 52 15.610 3 56 46. 480 4 4 47- 364 4 9 47. 7S0 4 II 23.671 4 14 16. 7J7 4 iS 35.a'ii Flexure and in- e.|uality of pivots Level. AzinuUh. Aberra- tion and coUi- niation. Rate. Seconds of corr. transit. s. R. A. Chronometer correction. V. s. , J 0. //. /;/. s. h. tit. s. s. -1-0. 249 +0. 003 +0. 376 +0. 520 -0.035 17.362 I 45 5S. 320 — I 13 19.042 —0. 076 4-0. 299 +0. 003 -|-o. 007 +o.5jy -o. 033 45-072 I 47 25. 835 19-237 +0. 119 +0. 302 -|-o. 002 —0.014 +°- 545 —0. 032 49. 006 I 48 29. 990 19. 016 — 0. lO-J +0.552 0. 000 - 1.888 f 1.644 —0. 027 17.424 I 53 58.420 [19.004] +0. 307 — 0. 002 — 0. 052 +0.555 — 0. 021 13-704 2 54-550 19. 154 +0. 036 +o. 332 — 0. 004 — 0. 236 -(-0. 620 — 0. 019 15-237 -> 2 56. 030 19. 207 +0. 099 +0. 300 —0. 004 —0. 002 +0. 542 — 0. on 15.769 2 II 56. 685 19. 084 -0. 034 -|-o. 4S6 — 0. 008 -1-394 + 1-302 —0. 004 14-832 2 19 55.780 [19.052] +0. 280 — 0. 005 +0. 145 +0.516 —0. 002 34- 1S7 2 22 15. 098 —I 13 19. 0S9 — 0. 029 -0. 559 +0. 484 — 0. 762 —I. 818 +0. 002 49. 568 2 27 30. 528 —I I3[i9.040] -0. 304 -ho- 333 — 0. 012 -0. 592 +0. 007 49. 526 2 32 30.519 19.007 — 0. 1 1 1 — 0. 267 +w. 311 -\-o. 096 -0.551 +0. oq8 6.266 2 33 47- 294 18.972 — 0. 246 — u. 283 +0.354 -1-0. 048 — 0. 559 +0. 012 15. 182 2 38 56.175 19.007 — 0. Ill -0.314 +u. 408 -u. 043 —0. 617 +0.016 45-930 2 43 26. Sio 19. 120 +0. 002 —°- 745 +1.007 — I. 306 -2.879 +0. 023 43- 474 2 51 23. 982 [19.491] . . . — 0. 273 +0.375 -l-w. 077 -0.551 +0. 028 47- 436 2 56 28. 422 19. 014 — 0. 104 -o. 341 +0. 4C9 — 0. 121 — 0. 702 +0.029 23. 005 2 58 3. 788 19.217 +0. 099 -3- 347 +0. 485 — 0. 13S -0. 725 +0. 032 16. 104 3 56. 805 19. 299 +0. 181 —0. 300 + 0. 424 0. OOO -0.58. +0. 036 36. 039 3 5 16.759 — 1 13 19. 280 +0. 162 NORMAL EQUATIONS. fo = — 0.090+2.491^(2' — 2. i83(Z'f j +0.127 +z. 263fl'«"+ 3.75WA- l + o. 249 — 2. 183^12' + 3. 751 «'«" + 25. 301 i/f — i.osidt [^ —0.349 — o.638(/<;' — 1.0921/,/"— I. 051 (/f + 15. 6791// j a' = + 0^739 (circle east); a'^ ^ + o» 289 (circle west); ^ = o«.53I (+ with circle east). Chronometer No. 1 254, at 3'' 38"M chron. time, i'l 13"! 19^.118 -j- 0^^.046 fast, losing o».053 per hour. AboumiiiL; a' ^ + o. 686 + i/a' circle E. «" = + 0.419 + ■/ da" ^= — O. 131 dc = -I- o. 014 dt = + o. 0l6 Jan. 12 u Piscium f Pisci'iin y And 10m. a xVrietis 55 Cassiop. y Trianguli Arietis t Cassiop. £ Arietis a Auriga: /i Tauri a Orionis a Columbce 6 Leporis ji Geminorum w. 7 7 7 7 7 7 7 w. 7 E. 7 7 7 7 7 7 E. 7 -> 48 45. 021 -0. 275 +0. 207 +0. 131 -0. 553 — u. 100 44.431 3 54.410 — 0. 271 +0.039 + 0. 151 -0.551 — 0. 090 53-788 3 10 II. S90 -0. 350 +0. 119 -0.273 -u. 73» —0. 082 10.556 3 14 1.204 - -0. 307 +0. 130 — 0. 038 — 0. 598 — 0. 079 0.312 3 18 54.864 — 0. 476 +0. 244 -0. 952 —1-345 — 0. 075 52. 260 3 23 49-441 -c. 328 +0.216 -0. 155 -0. 659 — 0. 070 48. 445 3 25 3-323 — 0. 300 +0. 239 — 0. 001 -0. 584 — 0. 069 2.608 3 33 4- 164 — 0. 486 +0. 390 — I. 001 — 1.404 — 0. 062 I. 6oi 4 5 56.916 +0. 303 — 0. 345 L). 019 +0. 547 - 0. 034 57-368 6 21 34.908 +o. 363 t°- '74 — 0. 391 +0. 734 +0. 079 35-867 6 32 21. 916 +0.318 +u. 050 — u. I I I +0.581 +0. 080 22. 834 6 46 15-531 +0. 263 +0. 022 +0. 226 +0.511 4-0. loi 16. 654 6 48 43- 157 +0. 204 + 0.015 +0. 5S7 +0.617 +0. 116 44. 696 6 59 38-137 +0.232 + 0. 007 +0.417 +0. 547 +0. 125 39-465 7 29 20. 107 +0 306 —0. 020 — 0. 038 +0.553 +0. 129 21.095 I 35 38. 526 I 47 47 844 I 57 4- 645 2 54- 389 2 5 46.454 •^ 10 42. 459 2 II 56. 539 2 19 55 261 2 52 51 592 8 29 83s 19 16 816 33 10 757 35 38 680 5 46 30 488 6 16 15 150 I 13 5 905 5 944 5 911 5 923 [5 706] 5 986 6 069 1 13 [6 340] I 13 5 776 [6 032] 6 028 5 897 6 016 6 023 I 13 5 945 -o. 047 -o. 008 -o. 041 -o. 029 +0. 034 +u. 017 -o. 176 +0. 076 u. 065 +0. 064 +0. 071 — 0.007 Assuming a' = + 611 + da' circle W. a" = + 0. 616 + da" " E. c = + 0. 561 + dc " E. Z \T = — ii' 13" 5''-963 + dt. I NORMAL EQUATIONS. - o. 270 + 2. 275 da' + 2. 959 dc — o. 328 dt '] whence da + 0.064 +i.862i/a"+ 1.546 (/r— o. 559 i* I 1 + o. 840 + 2. 959 ,/,;' + I. 546 da't + 19. 587 dc — O. 559 a'^ | (^ — 0.042 — o. 328 a?(z' + 1. 398 £/«" — o. 559 at + 13. 200 (//' I «/ =^ + 0^.531 (circle west) ; «" ^ + o».6o6 (circle east) ; c = 00.531 (+ with circle east). Chronometer No. 1254, at 4'' 46"'.y chron, time, i'l 13'" 5'^.952 + 0^009 fast; losing o».05i per hour. da' = — 079 da" = — 009 dc = — 029 dt r^ 000 IN MEXICO, CEJSTEAL AMEKICA, THE WEST INDIES, ETO . 67 Tranuts of stars observed at I 'e, a Cruz, .W i/a-, Ay Lieut. Charles Lain/, U. S. Navy, with transit No. ijo.f, to Jelermine the curredwu of .ulereal c/ux Date. Name ol Star. Circle. No, of threads. 'rransil over mean ot threads. Flexure •md in- ecjuality ul' pivots. Level. ^V/iliiuLll. .Mierra- tiou and eoUi- niatiun. Kate. Seconds of corr. transit. K. A. Clirononieter correction. V. 1889. Jan. IS V Pibciimi 1- 7 /i. m. ,1. •> 48 40, j 1 1 -t 0.275 s. —0. 047 s. + U. lOI s. i 0. 381 — u. 038 s. 40. 983 //. w. s. 1 35 38-49'-' -■ 13 2.493 s. +0. 197 Piscium 7 2 5-^ 32- 943 -)-o. 281 — 0. 107 + 0.076 + 0. 38s — 0. 035 33-685 I 39 31. 102 2.377 +0.081 I Arictis . . . 7 3 -7-45& +0. 299 —0. 206 0. 000 + 0. 402 — 0. 029 27.922 I 47 25.642 2. 280 — 0. 016 fi Arielis . 7 3 I 3'-563 + 0. 302 — 0. 222 — 0. 008 +0. 405 — 0. 028 32. 012 I 48 29. 7,^4 2.228 -0. 068 50 Cassiuj). 7 3 6 sy. 543 ;-fo. 552 —0. 211 — I. 051 + i.225 — 0. 027 0. 031 I 53 57-504 [2.527] J Amlrum. . . . 7 3 10 6. 44S '--0.350 —0. 264 — 0. 212 +O.51I -0. 022 6. 811 I 57 4-588 2. 223 -0. 073 a Arictis . . . 7 3 13 56.151 +0. 307 -0. 233 — 0. 029 + 0.413 —0,019 56. 600 2 54. 347 2.253 — u. 046 ) Trianguli 7 3 23 44- 33« ^0. 32S -0. 255 --0. 120 +0. 456 — 0. 015 44- 732 2 10 42. 408 2.324 +0. 028 L Cassiop. . 7 3 32 57-37° -|-o. 485 -0. 383 —0.775 +0.971 — 0. 004 57 663 2 19 55- 130 [2-533] •^' Ccti E. 7 3 35 16.543 +0. 2S0 —0. 225 +0.081 +0. 385 — 0. 001 17-053 2 22 14. 922 -I 13 2. 131 -0.155 35 Arietis W. 7 3 49 59- 398 -0.315 -0. 268 — 0.069 -0. 473 40.009 58. 282 2 36 55. 862 — I 13 2.420 +0. 134 " Ceti . . 7 3 51 59-076 — 0. 2S3 -0. 244 + 0. 074 -0. 427 +0.010 58. 206 2 38 55-999 2. 207 — 0. 0S9 ^7 Cephei, H. . . 7 4 4 29.114 — 0. 745 —0. 656 -1.994 — 2. 200 +0. 020 23- 539 2 51 22. 606 [1-933] a Ceti . . . 7 4 931-238 -0. 273 — 0. 266 +0. 118 —0. 422 +0. 024 30.419 2 56 28. 268 2,151 -0. 145 n Persei . . 7 4 II 7.276 -0.341 -0.333 — 0, 185 -0. 536 +0. 025 5.906 2 58 3-569 2.337 4-0. 041 d Arietis .... 7 4 iS 19. S90 — 0. 300 — 0. 308 —0. 001 -0. 446 +0. 070 18. 905 3 5 16-599 2. 306 +0. 010 c Arietis ... 7 4 21 34- 269 —0. 302 —0. 316 - 0. 012 —0. 449 +0. 033 33- 223 3 8 31.000 2.223 -0.073 (f Tauri . . 7 4 31 53-030 —0. 2S1 0. 000 ^ 0, oSi —0. 426 +0. 041 52.445 3 iS 50. 165 2. 280 —0.016 •3 Tauri .... 7 4 34 12.004 —0. 282 -f 0.013 +0. 076 — 0. 426 +0.044 11.429 3 21 8.997 2-432 +0. 136 / Tauri , . 7 4 37 47-506 — 0. 258 +0.033 +0.052 -0.431 -|-o. 04S 46. 920 3 24 44-459 2. 461 Gr. 716 \V. 7 4 45 36-314 -0. 449 + u. 089 —0. 667 -0. 923 +0.055 34-419 3 32 32.013 — 1 13 [2.406] Assuming a' = + o. 441 + da' circle E. a" = + o. 437 + da" " W, e =-\-o.4sS + dc " E. /\T = — 1 1' 13™ 2'. 293 + dt. X(.)RMAL EQUATIONS. -O. 152 + 2. 496 da' — 3. 199'^''- , 203 (// ] whence da' - o. 030 + 0.098 +2. 6l2■ 13 -I 12 —I 13 I 12 I 13 —I 13 [o. 536] 59- 899 59. 898 59.881 [o. 293] 59-953 59-771 0.015 o. 018 +0. 022 -|- 0.021 -(-o. 004 -|-o. 076 o. 008 +0. 138 -1-0. 141 — I i2[57- 277] 59- 760 59. 800 59- 723 59- 723 59- 872 59. 896 59- 920 59- 963 [59-531] I 12 59.938 o. 117 — o. 077 o. 154 o. 154 — o. 005 +0. 019 +0. 043 -1-0. 086 -4-0.061 Assuming a' ^=-\-0.\y2.-\- da' circle E. 3" = + o. 405 + fl'a" " W. c = -(- O. 586 -I- (/i: " E. /\T = — I >■ 1 2m 59".86o + dt. NORMAL EQUATIONS. : — o. 275 -f- 2. 439 .o47 fast, losing o".o57 per hour. 70 TELEGRAPHIC DETERMINATION OP LONGITUDES T, '■ansits of stars obscrticd at Coatzni-palfos, IMcxito, by Lieut. Charles Laird, U. S. jVavv. luith transit No. 1S04, /" dctet-mine the correction of sidereal chronometer Negus No. I2S4- Date. Name of Star. E. i2 rt 7 Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate-. Seconds of corr. transit. R. A. Chronometer correction. V. 1889. Feb. 10 a Orionis h. III. s. 6 54 41-857 s. +0. 280 s. — 0. 229 .r. —0.013 s. +0. 228 s. —0. 083 s. 42. 040 5 III. s. 49 9- 926 //. III. s. -I 5 32-114 s. -0. 157 66 Orionis . 7 7 4 38. 863 +o- 275 — 0. 225 —0.017 +0. 226 — 0. 072 39- 050 5 59 6.736 32.312 +0. 033 1' Orionis 7 7 6 46. 238 -f-o. 292 -u. 239 — u. 004 +0. 233 — 0. 069 46- 453 6 I 14-346 32. 107 -0. !74 1 Geminorum . . 7 7 13 43-221 +0- 305 —0. 248 -\-o. 006 +0. 244 — 0. 061 43- 467 6 8 10.939 32. 52S +0. 247 P Canis Majoris . 7 7 23 51.157 -f-o. 240 -0. 193 — 0. 044 +0. 237 — 0. 049 21.348 6 17 49- 143 32 -200 -f 0. 076 V Geminorum 7 7 27 54. 656 +0. 301 — 241 4-u. 003 -f-o. 240 — 0. 043 54.916 6 22 22. 644 32. 268 +0.013 e Geminorum 7 7 42 38, 656 +0. 310 —0. 242 -|-o. 010 +0. 249 — 0. 023 38. 960 6 37 6.530 32.430 + 0. 149 24 H. Camelop. 3 7 49 24.968 +0. 654 -0. 505 -|-o. 276 + 1. 104 — 0. 016 26. 587 6 43 54-828 [31-659] (S Geminorum . . E. 7 8 19 1.957 +0- 305 — 0. 214 +0. 005 +0. 244 -(-0. 020 2.317 7 13 30- >30 —I 5 32. 187 — 0. 094 (T Hydrfc .... W. 7 9 38 30. 663 -0. 274 —0. 044 -j-o. 070 ■ -0. 266 +0.113 30. 262 8 32 58- 125 -I 5 32.127 — 0. 144 c Hydr.v . . . 7 9 55 4-936 -0. 279 —0. 025 +0-057 — u. 267 +"■ 136 4-558 8 49 32- 264 32. 294 +0.013 Ilyilr.L^ . . 7 10 14 8. 71 1 — 0. 271 — 0. 002 -|-o. 080 — 0. 266 -\-o. 162 S. 414 9 8 36.094 32. 320 +0. 039 I Draconis .... 7 10 26 53. 83b -0. 883 +0. 043 —1.769 -i,868 -fu. 177 49. 196 9 21 19.153 [30- 043] Gr. 1564 . . . 7 10 38 20. 272 - 0-S15 +o- 050 — 0. 636 -0.768 +0. 191 28. 594 9 32 46.472 [32.122] e Leonis W. 7 to 45 6. 586 — 0. 309 +0. 039 — 0. 027 - -0. 290 -|-u. 200 6. 199 9 39 43- 728 -I 5 32.471 +0. 190 Assuming; NORMAL EQUATIONS. : + 0. 286 -|- 1. 1^82 da' o, 459«' o. ill-f(/«' circle E. fo: o. 190 -\-da" " W. I o. 207 -)- dc " E. I ii>5"'32».28i +(*. (_ a' = — 0S.072 (circle east) ; a" = -(- 0^.281 (circle -west) ; ;: = 0^.246 (-f- with circle east). Chronometer No. 1254, at 8'' 2^.9 chron. time, l'' 5'" 328.281 -j- 0^.079 fast, losing o".o74 per hour. da"-- dc -. dt -. — o. 184 + 0. 091 + o. 038 + o. 003 I'eb. 12 :9 H. Camelop. . n Orionis 7/ Leporis . . . ri Urs. Minoris . 8 Monocerotis . . V Geminorum . . a Canis Minoris . f Canis Majoris . I," Geminorum . . 25 Camelop. A Geminorum rf fjeminorum p Geminorum a^ Gemiaiorum 25 Monocerotis a Canis Minoris K Geminorum B Geminorum 53 Camelop. . . ;C Geminorum 3 Urs. Majoris, H E. E. W. W. 6 9 46. 986 6 54 39- 723 6 56 50. 848 7-13 13-877 7 23 23.020 7 27 52. 123 7 45 45-468 7 59 45-893 831. 621 8 13 20. 814 8 17 13-856 8 19 o. 640 8 27 29. 540 8 33 2-457 8 37 16. 566 8 39 o. 550 ■5 43 15- 970 8 44 2. 711 8 57 46.357 9 2 16. 628 9 7 19-564 +0- 727 +0.362 —2. 108 +2. 142 —0. 045 48. 064 -f 0. 280 -0. 045 +0. 086 +0. 407 — 0. 029 40- 423 +0. 246 -0. 039 +0. 252 +0.417 — 0. 028 51.692 + I.2I8 — 0. 195 +7-455 —6. 844 -0. 025 IS- 485 +0.276 —0. 044 +0. 107 +0. 406 — 0, 019 23- 746 +0. 301 — 0. 048 — 0. oiS + 0.431 -0, 018 52-771 +0. 242 — 0. 039 -l-o. 270 -1-0.422 — 0. on 46- 352 +0. 220 — 0. 092 +0. 380 +0. 462 — 0. 006 46- 857 +0. 302 — 0. 145 —0. 022 +0-433 —0. 005 2. 184 --"- 737 + 1. 114 — 1. 174 —3- 467 — 0. 002 17-546 -0. 295 +0. 434 +0. 004 — 0. 464 0. 000 13-537 —0. 304 +0. 447 -0. 013 — 0. 482 0. 000 0.288 —0. 324 +0. 469 -0. 047 — 0. 526 +0. 003 29. 081 -0. 324 +0. 501 —0. 048 —0.527 +0. 005 2. 066 —0. 263 +0. 425 -f-o. 063 — 0. 447 +0. 007 16.351 —0. 278 +0. 460 +0. 036 — 0. 448 +0. 007 0.317 -0. 309 +0. 534 —0.021 — 0. 491 +0. 008 15.691 —0. 316 +0- 533 -0-033 — 0. 506 +0.010 2.417 -0. 425 +0.418 — 0. 230 — 0. 909 +0. 014 45.217 -0.316 +0.310 -0-033 -0. 505 +0.015 13.099 —0. 496 +0. 497 -0- 357 —1-233 -f 0. 019 17-994 5 4 17- 5 49 9- 5 51 21. 6 7 56. 6 17 53- 6 22 22. 6 40 16. 6 54 16. 6 57 31- 7 7 47- 7 " 43- 7 13 30- 7 21 58. 7 27 31. 7 31 46- 7 33 30- 7 37 45- 7 38 31- 7 52 14- 7 56 42- 8 I 47- 569 900 196 730 493 626 026 583 944 142 303 118 818 667 051 061 329 996 765 663 162 5 [30- 495] 30. 523 30. 496 [30- 755] 30- 253 30. 145 30. 326 30. 274 5 30- 190 5 [30- 404] 30. 232 30- 170 30. 263 30. 399 30. 300 30. 256 30. 362 30.421 [30- 450] 30- 436 5 [30. 832] -1-0. 208 -fo. 181 — o. 062 — o. 170 -)-o. oil — o. 041 — o. 125 - o. 073 -o. 145 — o. 052 +0. 085 — o. 023 -o- 05s +0. 048 +0. 107 +0. 122 Assumincr s. = + 0, ' = + 0. = + 0, 462 + da' circle E. 102 + da" " W. 414 + «' + 2. essfl'r- — O. 807 dc - o. 6^2 dt "I whence da o. 438 dt [ o.2i2-\-de " E. ] -j-o. 374-f- 2. 655fl'«'— o. 8o7rtfe" AT = — i'^^'^2i)'.ygS-\-dt. [^ — 0.022 — o.6^2da' — o./^-^Sda" a' ^ -\- o".763 (circle west) ; r?" = -|- o".686 (circle east) ; c = Chronometer No. 1254, at 6I' 37™. 2 chron. time, l^ 5™ 29».773 -|- o'. -|- 12. 700«'r-|- 2.223 a'/ I -|- 2. 223 de 4- 6. 940 dt J : oi!.3i3 ( — with circle east). 026 fast, losing o".o&9 per hour. s. da' = + 134 da" = + 054 dc = — 061 dt = + 038 Feb. 14 ; Tauri d Tauri . £ Tauri m Persei . Gr. 848 a Caraelop. i Tauri IT* Orionis I AurigjE , I Tauri I I Orionis . 17 Camelop. Gr. 966 a Leporis f Tauri IT Orionis 130 Tauri . Orionis W. E. 5 '8 57. 193 -0- 293 — 0. 216 -\-o. oog 5 22 0. 669 — 0. 296 — 0. 247 +0. 003 5 27 36.828 —0. 299 — 0. 293 —0. 003 5 31 5-570 — 0. 350 —0. 416 — 0. 107 5 39 25-893 — 0. 616 — 0. 900 —0. 644 5 48 31.246 —0. 468 -0. 677 -0. 345 5 50 21-720 — 0. 29S —0.431 — 0. 002 5 53 56.890 — 0. 271 -0. 392 +0. 054 5 55 15-043 — 0. 326 -0. 471 +0.057 6 I 55-494 -ho. 303 -0. 770 — 0. 022 6 3 41-428 + "-293 — 0. 810 -1-0. 018 6 25 9. 286 +0- 442 +0. 032 -0.551 6 30 21.557 +0. 597 -|-0. 010 —I. 146 6 33 17-487 -j-o. 240 —0. 002 +0. 219 6 36 28. 136 +0- 303 — 0. 010 — 0. 019 6 38 37-883 -|-o. 265 — 0.013 -|-o. 126 6 46 25. 504 +0. 297 — 0. 028 +0- 003 6 54 37- 328 +0. 280 -0. 039 +0.031 — o. 364 -o. 367 —0.371 —0.478 —1,425 — o. 868 — o- 370 —0.351 — o. 418 +0- 334 +0-332 -|-o. 684 + 1- 199 +0- 327 +0- 333 +0.3" +0. 326 +0. 314 — 0. 050 56. 279 -0. 047 59-715 — 0. 042 35-820 -0. 036 4-183 — 0. 027 22. 281 — 0. 018 28. 860 — 0. 015 20. 604 — 0. oil 55-919 — O.OIO 13-875 — 0. 003 55-336 —0. 002 41-249 -|-0. 022 9-918 -1-0. 028 22. 245 + 0-032 18. 303 +0. 035 28.778 +0- 038 38.610 -(-0. 046 26. I4S +0.055 37-972 4 13 4 16 4 22 4 25 4 33 4 43 4 44 4 48 4 49 4 56 4 58 5 19 5 24 5 27 5 31 5 33 5 40 5 49 28. 238 31.640 7.768 36. 040 54- 587 o. 900 52. 644 28. 008 45- 744 27.49S 13-434 41.521 54-517 50. 226 0.683 10. 478 57.922 9.874 5 28. 001 28. 075 28. 052 28. 143 [27- 695] [27.960] 27. 960 27.911 5 28. 131 5 27. 838 27.815 [28. 397] [27. 728] 28.077 28. 095 7,8 132 28. 226 5 28. 098 o. 039 0.035 0.012 +0. 097 — o. 080 -o. 129 -o. 091 -O. 212 -o. 225 + 0-037 + 0-055 ■j-0. 092 -1-0. 186 -t-0. 058 NORMAL EQUATIONS s. Assuming a' =-{- o. ^oo -\- da' circle E. fo = -|- o. 876 + 2. 817 4'". 9 chron. time, ii' S™ 28«.040 -j- 0^.020 fast, losing o».o67 per hour da" = — o. 023 dc ^4-0. 003 dt = -)- o. 007 72 TELEGRAPHIC DETERMINATION OF LONGITUDES Transits of stars observed at Coatzaeoalcos, Mexico, by Lieut. CJiarles Laird, U. S. Navy, ivith transit No. IS04, to de/e. /^ Negus No. 1254. iiie the correction of sidereal chronometer Date. Name of Star. ui ■a 0) J- "0 6 'A Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate. Seconds of corr. transit. R. A. Chronometer correction. V. 1889. Feb. 15 y Tauri E. h. m. i. S 18 54-344 J. +0- 293 J. — 0. 141 s. +0. 027 s. -1-0. 618 s. -0.034 s. 55- 103 /;. i/i. s. 4 13 28. 221 tl. 111. s. — t 5 26.882 s. +0. 121 (J Tauri 5 21 57-665 -|-o. 296 — 0. 162 -|-o. 008 +0. 625 —0. 026 58-506 4 16 31-623 26. 883 +0. 122 e Tauri . . 5 27 33-904 +0. 299 — 0. 204 —0. 008 +0. 631 — 0. 021 34. 601 422 7.751 26. 850 -f-o. 089 a Tauri 5 34 58- 934 +0. 294 — 0. 254 -|-o. 028 -|-o. 622 — 0. 015 59. 608 4 29 32. 790 26.818 +0.057 Gr. 848 . S 39 20.821 4-0.616 -0. 594 —1.850 +2-423 — 0. 014 21-459 4 33 54-5'o [26. 949] u. Eridani . 5 45 22. 758 -fo. 264 -0, 293 +0. 199 +0.598 —0. 005 23-515 4 39 56-908 26. 607 -0- 154 a Camelop. . 5 48 27.081 +0. 468 -0.557 — 0. 992 + 1-477 —0. 003 27- 505 4 43 0. 855 [26. 850] i Tauri . . 5 SO 18.717 +0. 298 -0. 349 — 0. 005 -|-o. 629 - 0. 001 19.289 4 44 52. 628 26. 661 -0. 100 TT* Orionis . . 5 53 54-067 f 0.271 -0-352 -^o. 156 +0. 598 -|-0.00I 54- 737 4 48 28.008 26. 729 -0,032 I Aurigne . . E. 5 55 11-933 +0. 326 — 0. 400 — 0. 165 +0.711 -|-0. 002 12.407 4 49 45. 726 —I 5 26.681 — 0. 080 17 Camelop. . . W. 6 25 10. 743 -0. 442 +0. 298 -0. 957 — 1.402 -1-0. 028 8.268 .5 19 41-484 -I 5[26.784] . . . Gr. 966 . . b 30 25. 307 -0- 597 +0. 483 -I 991 —2. 459 +0. 032 20. 775 5 24 54-451 26. 324 . . . ?>' Orionis . . 6 34 II. 123 -0. 283 +0.253 +0. 095 — 0. 646 +0. 036 10.578 5 28 43. 603 26. 975 +0.214 f Tauri . . 6 36 28. 241 -0. 303 +0. 340 — 0. 034 — 0. 683 +0. 038 27.599 5 31 0. 668 26.931 +0. 170 130 Tauri . . 6 46 25.368 -0. 297 +0. 357 -|-o. 005 — 0. 669 +0. 047 24. 811 5 40 57-909 26. 902 -1-0. 141 K Orionis . . 6 47 56.613 — 0. 254 +0.313 -1-0. 292 — 0. 646 -|-o. 048 56. 366 5 42 29. 645 26. 721 — 0. 040 a Orionis 6 54 36. 938 — 0. 280 +0. 373 -|-o. 116 —0. 643 +0.053 36-567 5 49 9-861 26. 706 -0. 055 V Orionis . . 7 641.358 — 0. 292 -1-0. 488 +0- 037 — 0. 658 -|-o. 063 40. 996 6 I 14. 281 26.717 — 0. 044 ■q Geminorum • i 7 7 13 38-454 -0- 305 —0. 098 — 0. 05 1 — 0. 690 -|-o. 070 37-380 6 8 10.880 26. 500 — 0. 261 V Geminorum . . W. 7 7 27 50. 178 — 0. 301 — 0. 061 — 0. 024 -0.675 -1-0. 082 49- 199 6 22 22.589 —I 5 26.610 -0. 151 o. 478 dt '\ whence da da NORMAL EQUATIONS. = -|-o. 156-f- 2. 644rt'a' — 2.e,lodc -|- 0.163 +2. 435«'n"+ 2. 032«<: — o.2T,o dt — 1.774 — 2. $loda' -\- \i.OT,2da" -\- 2^.']()6 dc -\- 0.031 (ft [ — o. loi — Q.^-j^da' — o. 23oa'rt:" -f- o. 031 rfc -f- 16. 868c// I a' = -(-0S.540 (circle east); a" = -f-o».6i7 (circle west); i-^o».6l7 (-|- with circle east). Chronometer No. 1254, at6''20"'.9chron. time, ii'5"26s.76i ±o«.023 fast, losing o".o5 2 per hour. Assuming a' =-{- o. ^22 -\- da' circle E. a" = -|- o. 709 -|- da" " W, ^ = + O. 536 -I- sc)-7't\/ at Satina Cni-:, Mexico, t>y Unit. Charles Laird, CL S. A'aTV, "^vith traiisit A^o. 1^04, to dctrrvniir the rorrcction of sidereal chronometer y\ri,v/.9 No. 12^4. Date. Name of Star. 7j u 6 Transit over mean of threads. IHexure and in- equality of pivots. Level. Azimuth. Alierra- tion and colli- mation. Rate. Seconds ofcorr. transit. Ts.. A. Chronometer correction. V. iSgo. ; Mar. 13 1 ,? Canis Minoris . . ^^^ i 7 /;. m. s. 8 29 50. 890 s. — 0. 284 s. — 0. 091 -1 u. 049 +a 183 — 0. 134 50.613 h. m. s. 21 8. 120 Ju in. s. —I 8 42. 493 +0. 012 a- Geminorum 7 8 36 14. 208 —0.321 — 0. 109 — 0. 117 +0. 216 — 0. 119 I3-758 27 31.297 42.461 — 0. 020 25 Monnccroli.<; 7 8 40 28. 500 — 0. ^fifj — 0. 104 + 0. 124 +0. 183 — 0. 108 28. 329 31 45-714 42.615 +0. 134 a Canis iSIinoris . 7 8 42 12. 466 — 0. 280 — 0. I ID +0. 067 +0. 184 — 0. 106 12. 221 33 29-747 42. 474 — u. 007 K C;eminorum . . 1 7 8 4r5 27. 876 — 0. 30S -0. 124 -0.059 +0. 201 —0. 094 27.492 37 45-012 42.480 +0. 001 3 Geminorum . 7 8 47 14. 469 -0.314 -u. 126 -0. 086 +0. 207 — u. 092 14. 05S 38 31.664 42. 394 —0. 087 Or. 1374 .... 7 8 55 38.72S -0. 550 — 0. 220 — I. 126 +0. 673 —0. 086 37-419 46 55. Ill [42. 308] u> Cancri . 7 9 2 56. lOI -0. 309 -0. 109 —0. 066 -t 0. 203 —0. 054 55.766 54 13-239 42.527 +0. 046 X Geminorum . 7 9 5 25.220 — 0. 314 —0. 108 — 0. 0S5 +0. 207 — 0. 046 24. 874 56 42. 385 42.489 +0. 008 3 Ur5. >[ajoris, H. . 7 9 10 30. 264 — 0. 475 -0.158 -0. 790 +0. 506 -0. 035 29.312 8 I 46. 960 [42. 352] f Cancri . . . i W. 7 9 14 33-874 -0. 297 -0. 095 — 0. 012 +0. 192 —0. 025 33-637 8 5 51. 120 —I 842.517 +0. 036 (T Hydnc . . . E. 7 9 41 39-910 +0.277 -1-0. 267 +0. 108 —0. 223 +0. 039 40.378 8 32 57-941 — I 8 42. 436 —0. 04s )' Cancri . . . 7 9 45 34-413 +0. 304 + 0.281 — 0. 054 — 0. 239 +0.050 34-755 8 36 52. 265 42. 490 + u. 009 fi Cancri . 7 9 47 5- 177 -f 0. 298 + 0. 268 —0. 022 -0. 235 +0. 056 5-542 8 38 23. 104 42. 448 -0-033 . Cancri . 7 9 48 41.511 + 0-315 +0. 282 — 0. 129 -0. 255 +0.057 41.781 8 39 59-354 42. 427 —0. 054 e riydra; 7 9 49 36. 454 +0. 281 + 0. 246 +0. 082 —0. 224 +0. 060 36, 899 8 40 54.410 42. 489 —0. 007 02 Cancri (med.). 7 9 56 11.094 +0.319 + 0.255 r-o. 150 — 0. 260 +u. 076 ■1-334 8 47 28. 897 42.437 — 0. 044 C Hydrre . . . 7 9 58 14. 164 +0. 280 + 0.213 + 0.086 —0. 224 +0.081 14. 600 8 49 32- 126 42. 474 —0. 006 83 Cancri . . . 7 10 21 29. 969 +0. 297 + 0. 220 —0. 019 -0. 234 +0. 137 30. 370 9 12 47. 809 42.561 — 0. 020 A Urs. Majoris . . 7 1° 31 30-557 +0. 430 +0. 363 —0. 829 — u. 500 +0. i6i 30. 1S2 9 22 47-855 [42. 327] Gr. 1564 . t 7 10 41 29. 621 +0.485 + 0.418 -1. 167 —0. 644 +0. 185 28. 898 9 32 46. 330 [42. 568] Lennis . . ; 7 10 43 56. 260 +0. 286 + 0. 264 +0.051 — 0. 227 +0.192 56.726 9 35 14-278 42. 448 -0. 033 e Leonis . . K. 7 10 48 15. 743 -1-0. 308 + 0. 297 —0. 078 -u. 244 +0. 202 16.228 9 39 33-752 —I 8 42.476 +0. 005 NORiMAL EQUATIONS. s. Assuming a' -= + o. 139 + n'n'' circle W. f o^ + o. 165 + i. 9040(2' + 3.656^'^ „// = + o. 608 + (/(?" " E. J — o. loi +2. 3650'rt"— 3.oi2n'c— I. 291* c ^-0.042 + 0^ " E.l + 3. 350 + 3.656n'ffl'— 3.0i2a'«"+-28. g62(/,+ 1.350^// j l\'^ - — ii|g""42».486 + a'A ( +0. 008— I. 2i7n'i2'— I. 29irf«"+ i. 350r/c-+ 19. 9161// J (2' = + o".36l (circle west) ; a" = -|- o".502 (circle east) ; c = o».203 ( — with circle east) Chronometer No. 1254, at 9= 25™.o chron. time, i'> 8™ 42".48i -|- o. 005 fast, losing o".i46. s. I. 217 dt "I whence da' ^ + o. 222 I da" ^ — o. 161 dc = — o. 1 60 dt =1 + 0.013 76 TELEGRAPHIC DETERMINATION OP LONGITUDES Transits of stars obseiiicd at Salina Cru^, Mexico, by Lieut. Charles Laird, U, S. Navy, with transit No. 1S04, to dctc, A'lXiis No. I2j,f. ine the correction of sidereal chronometer Date. 1889. Mar. 14 Name of Star. ^ Canis Minoris . a' Geniinorum . o Canis Minoris . a Geminorum . 7r Geminorinn . Gr. 1374 . u' Cancri . . X Geminorum . 3 Urs. Majoris, H Urs. Majoris 7; Cancri . a Hydrce . . y Cancri . . . (! Cancri . . . ( Cancri . , . E Hydree . . (7^ Cancri . ^ Hydrce . , a Cancri . W. W. Transit over mean of threads. 8 29 46. 774 8 36 9- 970 8 42 8. 338 8 46 23. 587 8 48 59-934 8 55 34. 200 9 2 51-865 9 5 21.076 9 10 25. 893 9 29 43- 284 9 34 57-091 9 41 36- 745 9 45 31-487 9 47 2. 190 9 48 38.571 9 49 33- 394 9 56 8.137 9 58 11.053 10 I 4. 667 Flexure and in- equality of pivots. -f-o. 284 +0.321 +0. 280 + 0.308 +0. 324 +0. 550 +0. 309 +0.314 +0.475 —0.414 — o. 301 — o. 277 — o. 304 — o. 298 —0.315 -0.281 -0.319 — o. 280 — o. 289 Level. +0. 045 +0. 04s +0. 036 +0. 036 +0. 036 +0. 130 +0. 105 Azimuth, q-o. 120 +0. 198 +0- 211 +0. 147 +0- 129 +0- 131 +0. 127 +0. 132 +0- 017 +0. 123 +0. 105 +0. 104 +-0.038 — o. 091 +0. 052 — o. 045 — O. lOI — o. 870 — o. 05 1 -0. 038 o. 611 -o. 923 -o. 05s +0.073 o. 068 o. 028 o. 163 o. 103 o. 189 +0' 108 +0. 044 Aberra- tion and coUi- mation. +0. 004 + 0.005 +0. 004 +0. 004 +0. 005 -|-o. 014 +0. 004 +0. 004 +0. on — o. 091 — o. 047 — 0.044 — o. 047 — o. 646 — o. 050 — o. 044 —0.051 — o. 044 — o. 045 Kate. — o. 130 — o. 114 — o. 099 — o. 088 — o. 081 — o. 064 — o. 047 — o. 040 — o. 027 -(-0.019 +0. 034 +0.051 +0.061 -(-o. 065 -I- 0.068 +0.071 +0. 087 +0. 092 ■4-0. 100 Seconds of corr. transit. 47-015 10. 136 8.611 23. 802 o. 217 33- 960 52. 185 21.436 25-939 42. 086 56.869 36. 677 31. 260 2. 010 38- 243 33- 260 7-788 11.034 4-581 R. A. h. m. s. 7 21 8. 106 7 27 31-279 7 33 29.732 7 37 44- 995 7 40 21.257 7 46 55- 045 7 54 13.222 7 56 42.369 8 I 46-913 8 21 3. 219 8 26 17. 870 8 32 57-931 8 36 52.239 8 38 23.093 8 39 59- 333 8 40 54. 399 8 47 28. 886 8 49 32. 116 8 52 25.516 Chronometer correction. h. m. s. -i 8 38. 38. 38- 38. 38- [38- 38- 39- -1 8[39. -I 8[38. 38. 38- 39- 38- 38- 38- 38- 38- -i 8 39. 909 857 879 807 960 915] 963 067 026] 867] 999 746 021 917 910 861 902 918 065 s. 0.015 — o. 067 — o. 04s — o. 117 — o. 036 +0. 039 +0. 143 +0. 065 0.178 +0.097 — o. 007 o. 014 o. 063 0.022 o. 006 +-0. 141 Assuming NORMAL EQUATIONS. = -Ho.2i3-|-i.858rf«' — 0.282 -\-i.o<)o da" — 2.212 — 2. i<)2 da' -\- I. tifii) da" /\T =— ill 8"" 38s.936+-a'A [ —0.019 — i. 882 «'«' -j-o. 377 ofe" a' = -|- o".279 (circle east) ; a" = -\- o».632 (circle west) ; c = Chronometer No. 1254, at gii 2i™.4 chron. time, i" %<" 38».924 -|- o" s, = +0 ' = -Ho c = — o 222 -)- da' circle E. 497 -I- da" " W. 068 -|- dc " E. — l.392(/c — 1.8820'/ l whence o'a' =-|-o.0S7 +- I.4i9a'^-|- 0.3770'/ I da" = -\-o.\iS -j- 24. 024 dc — 1 . 449 de \ dc = -j- o. 092 — I. 449 (/c-(- 16. 749 fl'/ J dt = -f-o. 012 o''.024 (-|- with circle east). 015 fast, losing 0M5I per hour. Mar. 1 5 25 Camelop. . . . E. 8 16 14. 186 +0. 879 -1-0. 080 — I. 221 +0. 202 — 0. 724 13.402 7 7 43- 284 -I 8[30. 118] . . . /I Geminorum 8 20 13.764 +0. 295 -f-o. 004 — 0. 001 +0, 027 0. 711 14-378 7 n 42.898 30. 480 +0. 012 S Geminorum 8 22 0. 494 +0. 304 0. 000 — u. 019 +0. 028 —0. 706 0. lOI 7 13 29.699 30. 402 — 0. 066 p Leonis . . II 35 29.065 +0. 285 0. 000 -|-o. 019 +0. 026 -0. 174 29. 221 10 26 58. 822 30- 399 — 0. 069 41 Leonis Minori s . II 45 54-011 +0. 306 -|-u. 002 — 0. 025 +0. 028 — 0. 146 54- 176 10 37 23.669 30. 507 +0- 039 46 Leonis Minori s . II 55 37-461 +0. 327 +0. 007 — 0. 067 +0. 032 — 0. 119 37-641 10 47 7-176 30- 465 — 0. 003 a Urs. Majoris 12 5 24. 961 +0.422 -j-o. 010 — 0. 265 +0. 056 — 0. 092 25. 092 10 56 54-319 [30- 773] X Leonis . . . 12 7 48. 547 +0. 283 +0. 007 +0. 025 +0. 026 — 0. 085 48. 803 10 59 18.300 30- 503 +0. 035 f^ Leonis . . . 12 9 45,511 +0- 27s +0. 007 +-0. 040 +0. 026 — 0. 072 45-787 1 15-371 30.416 — 0. 052 e Leonis . . . E. 12 17 55-996 +0. 294 +0. 009 0.000 +0. 027 -0. 057 56.269 8 25. 769 —I 8 30. 500 +0. 032 t Leonis . . . W, 12 26 40.000 — 0, 287 — 0. 121 +0.016 — 0. 067 -0. 037 39- 504 18 9.097 —I 8 30.407 — 0. 061 r Leonis . . . 12 30 45.336 — 0. 289 — 0. 122 +0. 040 —0. 066 — 0. 022 44.877 22 14. fllO 30. 267 — 0. 201 \ Draconis. . 12 33 22. 657 -0. 487 — 0. 207 — 0. 429 — 0. 192 —0.015 21.327 24 SI- 185 [30. 142] . . . f Hydrse . . . 12 36 4.354 — 0. 224 -0. 095 +0.157 -0. 077 —0.007 4. 108 27 33. 734 30. 374 — 0. 094 rj Virginis . . 13 22 45.137 -0. 283 — 0. 154 +0.051 — 0. 066 +0. 120 44. 80s 12 14 14-519 30. 286 — 0. 182 6 Canum Venat. 13 29 55-034 -0- 337 — 0. 105 — 0. 094 — 0. 086 +0. 140 S4.SS2 12 20 24. 043 30. 509 +0. 041 20 ComEe . . . 13 32 40- 583 — 0. 303 — 0. 063 —0.018 — 0. 07 1 +0. 148 40. 276 12 24 9. 648 30. 628 +0. 160 24 ComEe (seq.) 13 38 5-507 — 0. 299 — 0. 009 — 0. 010 — 0. 070 +0. 162 5.281 12 29 34.638 30. 643 +0. 17s 76 Urs. Majoris 13 45 16. 486 — 0. 428 +0. lOI — 0. 297 — 0. 147 1-0. 182 15-897 12 36 44- 983 [30- 914] . . . 31 Coma; Berenecis W. 13 54 49-298 — 0. 314 +0. 176 — 0. 043 -0.075 +0. 208 49- 250 12 46 18.555 — I 8 30. 695 +0. 227 NORMAL EQUATIONS Assuming a' = + 0. 257 + o'a' circle E. ro = + o. 108+ I. 8iS.- . . f Leonis . . . y' Leonis 35 n. Urs. Majoris / Leonis a Urs. Majoris . T^ Leonis . . . U w. E. Transit over mean of threads. h. til. s. 10 9 6. 771 10 17 3.328 10 21 15. 251 10 31 16. 086 10 35 53.610 10 43 41.594 10 48 I. 170 10 54 55-151 11 2 48. 008 II 9 44- 143 n ID 54.813 II 13 37-747 II 18 58.343 II 22 18.537 11 43 36-564 II SI 52.574 12 5 21.364 12 7 44.697 Flexure and in- et|iiality of pivots. Level. Azimuth. AliL-rra- tion and colli- mation. Rate. Seconds of corr. transit. J. —0. 463 s. — 0. 149 —0. 409 s. —0. 2S1 s. — 0. 122 s. 5-327 —0. 276 —0. 046 +0. 046 — 0. 107 — 0. 100 2.845 -0. 297 —0. 047 — 0. 008 — 0. 112 -|-u. ogo 14. 696 -0. 430 ^0.076 -0. 328 — 0. 240 —0. 066 14. 946 -0-331 — 0. 067 — 0. 088 — u- 134 —0. 048 52.942 —0. 286 -0. 077 -\-o. 020 —0. 109 - 0. 030 41. 112 —0. 308 —0. 099 — 0. 031 — 0. 117 —0.018 0-597 —0.31 1 — 0. 120 — u. 040 — u. 119 —0. 001 54- 560 +0. 281 +0. 045 +0. 038 +u. 068 +0. 020 48. 460 +0. 296 +0. 043 —0. 006 +0. 070 +0. 039 44- 585 -|-o. 289 +0. 041 +0. 019 +0. 068 -|-o. 042 54.272 f 0. 255 +0. 034 +0. 138 4.U. 068 +u. 049 38. 291 -|-o, 264 +0.031 —0. C43 +0-073 +0. 063 58.731 +0. 301 +0.031 — 0. 023 +0.071 +0.072 18.989 -1-0. 594 — 0. 124 — 0. 666 +0- 193 +u. 129 36. 690 +0. 287 -0. 138 -(-0. 026 -|-o. 068 +O-I51 52. 968 -f-o. 422 —0. 244 — u. 447 +0. 144 +0. 187 21. 426 +0. 283 — 0. 178 +0. 041 -|-o. 067 +0. 193 45- 103 R. A. //. III. s. 9 o 38- 725 9 8 35.972 9 '2 47-769 9 22 47. 769 9 27 26.145 9 35 14.246 9 39 33- 724 9 46 27. 762 9 54 21.580 10 I 17.682 10 2 28. 376 10 5 11.443 10 10 31. 272 10 13 51-953 1035 9-377 10 43 26. 225 10 56 54.315 10 59 18.301 Chronometer correction. h. m. -I 8[26. 602] 26. 873 26. 928 [27- 177] 26. 797 26. 866 26.873 8 26.798 8 26.880 26. 903 26. 896 26. 848 26. 959 27. 039 [26.313] 26. 743 [27. Ill] 8 26. 802 — o. 002 +0. 057 -o. 074 — o. 005 — o. 002 —0-073 -(-o. 009 +0. 032 -|-o. 025 — o. 023 +0. 088 ■\-o. 168 — o. 128 -0. 069 NORMAL EQUATIONS. Assuming a' ^ + o.l55+fl'a' circle W. ("0 = — o. 021 + 2. 303<^^a' + i.2i,'^dc — l . 485 (/^ "| whence ^/rt' =-(-0.044 3" = -|- o. 348 + (&" " E. j +0.205 -\-2.y1\da"— l.g^6dc — 0.3851*1 da" = — 0.060 c =-|-o. 106 + d'<: " E. ] +0. 150 + 3. 245 rfrt' — \.<)^(>da" -\-22.b2\dc-\- \.-j2gdt'i dc =—0.019 /\T = — I ii 8"! 26».88o + r//. (^ — o. 015 + 1.485 (&'-|-o. 385 £&"+ I. 729«^i--|- 15. i57(& J dt = + 0.005 rt' = + o''.l99 (circle west); a" = + 0^.288 (circle east); f = o".o87 (-|-with circle east). Chronometer No. 1254, at 10 55"'.ochron. time, i^Sm 26«.87I +0^.0 12 slow, losing o'. 160 per hour. Mar. 18 25 Camelop. . L Geminorum . ,3 Canis Minoris. a^ Geminorum a Canis Majoris. K Geminorum

Urs. Majoris Assuming a' .-=: + a" = Ar c = + AT = s. . s. . E. 7 7 7 7 7 7 7 7 E. 7 W. 7 7 7 7 7 7 7 7 W. 7 8 16 6.547 8 27 12. 920 8 29 30. 854 8 35 54- 104 8 41 52.549 8 46 7- 784 855 5-367 9 o 37. 308 9 2 35-993 9 10 10. 664 9 14 14-451 9 28 30.818 9 34 41-546 9 45 16.026 9 46 46. 784 9 48 23. 168 9 49 17-931 10 o 57.978 +0.879 +0. 848 -3- 193 +0- 833 -0. 133 5.691 +0.314 +0. 188 — 0. 104 +0. 121 — 0. 104 13-335 -|-o. 284 +0. 151 +0. 062 +0. 108 —0. 098 31-361 +0.321 +0. 103 -0. 145 +0. 126 — 0. 081 54.428 -\-o. 280 +0. 143 +0. 083 +0. 107 — 0. 066 53-096 +0. 308 +0. 183 — 0- 073 +0. 118 -0. 054 8.266 +0.312 +0. 258 — 0. 095 +u. 120 —0.031 5-931 + LI. 412 +0.397 — 0. 638 +0. 2l8 — 0. 016 37.681 +0. 309 +0.318 — 0. 082 +0.119 —0. 009 36. 648 -0. 475 +0. 764 — 0. 562 —0. 406 +0. 009 9-994 -0. 297 +0.477 — 0. 008 -0. 154 +0. 019 14.488 —0. 267 -0. 086 +0. 087 -0. 147 +0. 059 30- 464 —0. 302 — 0. 062 — 0. 022 -0.157 +0.073 41.076 —0. 304 — 0. 01 1 — 0. 027 -0. 158 +0. lOI 15.627 —0. 298 +0. 005 - 0. on -0- 155 +0. 105 46. 430 -0-315 +0.015 — 0. 066 — 0. 168 +0. 109 22. 743 -0. 281 -1-0. 018 +0. 042 — 0. 148 +0. Ill 17-673 —0. 467 +0. 095 -0. 567 -0- 393 + u. 142 56. 78S 7 7 42- 7 18 50. 7 21 8. 7 27 31- 7 33 29- 7 37 44- 7 46 42- 7 52 13- 7 54 13- 8 I 46. 8 5 51- 8 20 7. 8 26 17. 8 36 52. 8 38 23. 8 39 59- 8 40 54- 8 52 33- 928 010 050 207 672 927 464 982 154 749 050 237 718 187 044 287 354 234 -I 8[22.763] 23- 325 — 0. 047 23-3" — 0. 061 23. 221 — 0. 151 23-424 -f 0.052 23- 339 -0. 033 23-467 +0. 095 [23- 699] -I 8 23.494 +0. 122 -I 8[23.248] 23-438 +0. 066 23.227 — 0- 145 23-358 +0. 014 23- 440 +0. 068 23- 386 +0.014 23-456 +0. 084 23-319 -0. 053 -I 8[23. 554] NORMAL EQUATIONS. o^ — o. 002 + 2. 819 (/a' — 3. 946 f/c — o. 116 -\- 2. o\o da" -\- 2.93412',:- — 0.914 — 3.9461/17' +2. 9341/11" + 23. 4621/1- + 0. 163 — I. 579 1/«' — \.oi%da" — 0.005 dc -\- 14. ?>i)gdt J a' = + o«.447 (circle east); rt" = + o''.257 (circle west); - =o".i27 (+ with circle east). Chronometer No. 1254, at 9'' 6". 9 chron. time, l" 8'" 23«.372 -)- o».oi5 fast, losing o«. 158 per hour o. 373 + da' circle E. o.2S,i-{- da" " W 073 + 1/. " E. ih 801238.375-1-1//. I. 5791// "1 whence da' 1.0781// I da" O. 005 di I dc dt = + o. 074 =: O. 024 = + o. 054 = — o. 001 78 TELEGRAPHIC DETERMINATION OF LONGITUDES Transits of stars obscnjed at Salina Cruz, .1/ xii o, by Lieut. Charles Lainl, U. S. Navy, with transit .Vo. 1504, to determine the correction of iidcrcal chronometer Nci^ns No. 12^4. Date. Name of Star. W. 6 "A Transit over mean ol tlireads. Flexure and in- equality of pivots. Level. -(-o. 106 Azimuth. Aberra- tion and colli- mation. Rate. Seconds of corr. transit. R.A. Chronometer correction. V. 1S89. Mar. 30 10 Leonis Miiiori.s . 10 m. s, 35 15-748 s. -0.331 J. -1-0. 482 s. — 0. 156 s, —0. 115 J. 15. 834 h. III. s. 9 27 25. 980 //. m. a. — I 7 49. 854 s. — 0. 044 Leonis 10 43 4.616 — 0. 2S6 -|-o. 091 — 0. 1 1 1 -0.127 — 0. no 4.073 9 35 14. 120 49. 953 +0. 05s £ Leonis . . 10 47 23.867 -0. 307 +0. 099 \o. 169 -0. 137 —0. 080 23.611 9 39 hi- 600 50. on +0. 113 fi Leonis . . 10 54 17.753 —0.313 +0. ioi +0.219 — 0. 140 —0. 064 17.556 9 46 27. 640 49.916 +0.018 ir Leonis . . 2 11.774 — 0. 283 +0. 091 — 0. 145 — 0. 126 — 0. 043 11.268 9 54 21.480 49. 788 — 0. 1 10 T] Leonis . . 9 7- 790 — 0. 296 +0. 095 +0. 023 -0. 131 — 0. 025 7.456 10 I 17.586 49. 870 — 0. 028 a Leonis ... 10 18. 57S — 0. 289 +0. 093 — 0. 072 -0.128 —0. 020 18. 162 10 2 28. 280 49. 882 — 0. 016 32 Urs. Majoris w. 17 48.386 —0. 446 +0. 143 + 2. 010 -0. 303 — 0. 002 49- 738 10 9 59.710 -1 7[5o.o78] yi Leonis .... E. 21 41.454 +0. 300 — 0. 036 + 0. 098 +0. 092 +0. 008 41.916 10 13 51. 870 — I 7 50.046 + 0, 148 30 IL Urs. Majoris . 24 56. 500 +0. 449 — 0. 071 + 2. 342 +0. 212 +0.017 59-459 10 16 8. 978 [50.481] p Leonis ... 34 48. 426 +0. 285 —0. 082 -0. 137 +0. 087 +0. 043 48. 622 10 26 58. 760 49. 862 — 0. 036 41 Leonis Minoris . 45 13.047 +0. 306 -0. 133 + 0. 178 +0. 094 +0. 070 13.562 10 37 23. 610 49.952 4 0. 054 / Leonis . . . 51 15.876 -fo. 287 — 0. 149 — 0. 1 1 I J-0.087 +0.087 16.077 10 43 26. 170 49.907 +0.009 a Urs. Majoris 12 4 41.957 +0.422 -0. 338 + 1.927 +0. 185 +0. 122 44- 275 10 56 54. 190 [5o.o85]|-o.oii X Leonis . . . 12 7 8.076 +0. 300 — 0. 254 — 0. 178 +0. 087 +0. 129 8.160 10 59 18.273 49.887 p^ Leonis E. 12 9 5.141 -f 0. 275 — 0. 267 - 0. 291 +0. 086 +0. 153 5.097 II I 15.340 — 1 7 49.757 -0. 141 Assuming a' — I. 158 + da' circle W a" = ~v.\(i\-\-da" " E. c = + o. 074 + dc " E. AT =— ih7."49s.9i4 + '.24I (circle east) ; c = o».Io6 (+ with circle east). Chronometer No. 1254, at ii'' 18™. 6 chror. time, i'' l'"" 491.898 +o''.oi9 fast, losing o'. 160 per hour. ^ + o. 070 = — o. 077 = + o. 032 = + o. 016 Mar. 31 / Leonis . . . E. II 51 11.694 +0. 287 +0. 043 + 0. 237 +0. 205 — 0. 115 12.351 10 43 26. 164 -I 746.187 +0.015 46 Leonis Minoris . II 54 53.710 +0. 327 + 0.052 — I. 029 +0. 245 — 0. 106 53.199 10 47 7-112 46. 087 — 0. 085 a Urs. Majoris 12 4 43. 600 +0. 422 +0.054 -4. 103 +0. 433 — 0. 083 40. 323 10 56 54- 175 [46. 148] X Leonis . , . 12 7 3- 686 +0. 283 +0. 032 + 0. 380 +0. 203 — 0. 076 4.508 10 59 18. 269 46. 239 +0.057 pz Leonis . . . 12 9 0.381 +0. 275 + 0. 02g -|-o. 620 + u. 201 — L,.o73 1-433 I 15.338 46. 095 —0.077 » Leonis . 12 16 11.286 +0. 294 +0. 019 +0. 005 + 0. 209 —0.055 11-758 8 25. 749 46. 009 — 0. 163 f Urs. Majoris (med' 12 20 3.153 +0.321 +0. 009 -u. 858 f "• 237 — u. 045 2. 617 12 16. 594 46. 123 — 0. 044 a Leonis . . 12 23 10.953 +0.281 0. 000 + 0.438 + 0. 203 — 0. 039 n.836 15 25.639 46. 197 +0. 025 I Leonis . . . 12 25 54-563 +0. 287 —0.012 + ^- 234 +u. 205 —0,031 55- 246 18 9.094 46. 152 — 0. 020 T Leonis . . 12 29 59-908 +0.276 — 0. 031 + 0. 580 +0. 201 — 0. 022 0. 912 22 14. 608^ 46. 304 +0. 132 A Draconis . E. 12 32 42- 536 +0. 486 — U.077 —6. 205 +0. 586 — 0.016 37-310 24 51.074 —I 7 [46. 236] 3 Draconis . . . W. 12 44 II. 136 — 0. 461 +0.014 -5. 100 — 0. 626 +0. on 4-974 36 19.177 -1 7[45-797] /^ Leonis . . 12 51 11-447 -0. 293 + 0. 004 +0. 045 — 0. 250 +0.028 10. 991 43 24.789 46. 202 +0. 030 yi Virginis . 12 52 41.617 -0. 275 +0. 044 +0. 600 — u. 241 +0.031 40. 776 44 57.710 46. 066 — u. io5 7T" Virginis . . . 13 2 58.251 -0. 282 +0. 069 +0.393 -0. 243 +0. 056 28. 244 55 12.021 46. 223 +0.051 1 Virginis . 13 22 0. 360 — 0. 272 +u. 096 +0. 703 — 0. 241 +0. IOI 0-747 12 14 14. 602 46. 145 —0. 027 a' Crucis 13 28 9. 290 — 0. 121 + 0. 466 +5. 343 — 0. 521 +0.115 14-572 12 20 28. 401 46. 171 — 0. 001 20 Com^ . 13 31 56.540 -0. 303 +0.119 — 0. 252 — 0. 258 +0. 125 35.971 12 24 9.751 46. 220 +0. 048 76 Urs. Majoris 13 44 36.214 — 0. 428 +0.312 -4. 107 -0. 536 +0.155 31.611 12 36 45.121 [46. 390] 31 Comte Berenecis . 13 54 5.726 —0.314 +0. 146 -0. 592 — 0. 272 +0. 181 4.875 12 46 18. 677 46. 198 +0. 026 d Virginis . 13 57 47.446 — 0. 277 TO. 133 +0. 532 — 0. 241 +0. 186 47- 779 12 50 1.662 46.117 — 0. 055 c Virginis . W. 7 14 4 26.371 —0.288 + 0. 102 -f 0. 207 — 0. 246 +0. 202 26. 348 12 56 40.087 —I 7 46. 261 +0. 089 s, NORMAL EQUATIONS. Assuming Urs. Majoris 10 12.4JI +0.467 4-0. 016 -1-2. 251 +0. 596 — 0. 061 15. 690 8 5^ 32 697 [42 993] 0- Urs. Majoris . K. 10 8 18. 064 i-)-o. 463 0.000 +2- 097 +0. 585 — 0. 042 21, 167 9 38 176 — I 7[42 991] ^3 Cancri \V. 10 20 31. 196 —0. 297 +0. 143 -fo. 048 -0. 277 — 0. 014 30. 799 9 12 47 592 — I 7 43 107 +0 071 : // Urs. jNIajoris 10 30 29. 0S6 ' -0. 430 ~(-o. 200 -\-2. 062 -0. 590 -)-o. 009 30.337 9 42 47 359 [42 978] . Leonis 10 42 47. 624 —0. 2S6 +0. 128 — 0. 127 — 0. 267 +0.038 57.110 9 35 14 097 43 013 -0 023 t Leonis .... 10 47 16.854 -0.307 +0. 137 + 0. 194 -0. 2S8 -f-o. 048 16.638 9 39 33 575 43 063 i-o 027 i h Leonis . . 10 54 10,853 -0.311 +0- 143 +0.251 - 0. 294 +0. 065 10. 701 9 46 27 61s 43 086 i-o 050 ' — Leonis .... u 2 4.957 —0.283 +0. 134 — u. 166 — 0. 266 +0. 083 4-459 9 54 21 460 42 999 — 037 J? Leonis .... II 9 0. 918 —0. 296 +0. 144 —0. 026 -0. 275 -l-o. 099 0,564 10 I 17 567 42 997 -0 039 a Leonis . . . II 10 n. 574 1—0. 289 +0. I4S —0. 082 —0. 269 -|-o. 102 II. 1 84 10 2 28 259 42 925 ■ III 36 L'rs. Majoris . . W. 7 II 31 14-543 1 - 0.391 +0. 203 + 1.462 -0. 477 +0- 152 14- 493 10 23 32 458 -I 7[43 035] s. K( )RMAL lioUATK JNS. i. Assuming a' = — I. 013 -f da' circle E. «" = — 1.236 -I- ,/,;'' " W — ■},. o-]o dc — 1. 222 dt' -|- O. 064 -|- I. 648 r/(i" -f- 2. 364 (it — 1.20C) dt o. 26^ -\-dc " E. ] -j- o. 502 — 3. 070 (/<;' -j- 2. 364 r/ij-'' -j- 22, 442 (/(■ — 0.179 (A /\T = — ii> 7'" 43'.035 -|- dt. I -j- o. 036 — I. 222 '.243 (-|- with circle east). Chronometer No. 1254, at 10'' 20^.3, chron, time, i'' 7'" 43'.036 -[-o».oi2 fast, losing 0M40 per liour. whence da' = — o, 005 da" ^^ — o. on dc = — o, 022 dt = — o, 006 April 2 rr Hydra; . W. 7 y Cancri .... 7 i Cancri . . 7 a'' Cancri (med.) 7 f Hydra; .... 7 p Urs. Majoris . . 7 K Cancri .... 7 U Hydrae .... 7 /z Urs. Majoris . . 7 10 Leonis Winoris . 7 Leonis 7 // Leonis .... W. 7 "• Leonis . . . li. : 7 // Leonis .... 7 a Leonis . . . 7 f Leonis .... 7 y' Leonis .... 7 30 H. Urs, .Majoris , 7 /) Leonis 7 35 Urs. Majoris . . 7 41 Leonis !■:, 7 9 40 38. 420 9 44 32. 356 9 47 39- 244 9 55 8. 730 9 57 12.570 10 on. 236 lo 9 24, 908 10 16 16, 231 10 30 26. 071 10 35 5- 844 10 42 54. 546 10 54 7-556 11 2 0.866 II 8 56.663 II 10 7.483 II iS 10.588 II 21 30.776 II 23 45.485 II 34 37.800 II 42 44.514 1 1 45 2. 488 -0.277 — o. 304 — o. 298 -0.319 — o. 280 -o. 467 — o. 287 — o. 276 — o. 430 -o. 330 — o. 286 — u. 311 —0.079 — o. 030 -1-0. 019 — o. on — o. 015 — o. 038 — o, 046 -0.038 —0.0 17 -0.031 — o. 022 - o. 015 -f-u. 283 i — O. 270 -)-o. 296 — o. 282 +0.289 +0. 307 +0. 301 +0. 449 +0, 285 +0. 594 0,300 -o, 276 -o. 178 -o. 156 -0.213 -0.088 -o. 067 -o. 029 245 +0 122 +0 294 +0 341 — 195 + 2 5'5 — 104 — 263 + 1. 883 t-o 505 -0 116 + 229 — 157 + 0. 025 L>. 078 +0. 176 +0. 093 + 2. 229 — 0. 131 +2. 729 +0. 170 - o. 343 —0.370 o. 393 — o, 400 — o. 346 — o. 918 -o. 349 -o. 343 — o. 770 — o. 428 0.349 -o- 383 f o. 306 +0.317 +0.310 +0-331 +0.323 +0.748 +0. 307 -1-0.872 +0.331 -o, 139 — o, 129 — o. 118 — u. 104 — o, 100 -o, 093 — u. 071 -o. 055 — O. 022 — o. on -(-u. 006 +0.032 +0.053 -(-o, 067 -|~o, 070 -1-0,088 +0, 097 -|-0. lOI 4-0. 127 -|-o. 146 +0.151 37. 337 31 645 38 748 8 237 1 1 636 12 235 24.051 15 256 26 968 5 539 53 779 7 loS I 081 57 086 7.798 II 312 31 434 48 799 38 309 8 32 57-665 8 36 51.972 8 39 59-062 8 47 28, 614 8 49 31-179 8 52 32, 644 9 I 44, 488 9 8 35, 758 9 22 47, 327 9 27 25,933 9 35 14.085 9 46 27. 602 9 54 21. 449 10 I 17.556 10 2 28. 248 10 lo 31, 650 10 13 5 1 , 842 10 16 8, 899 10 20 58, 734 10 35 9,029 3.411 j 10 37 23. 5S9 48,478 -1 7 39.672 39- 673 39. 686 39- 623 39. 757 [39.591] 39. 563 39. 498 [39.641] 39, 606 39- 694 -I 7 39, 506 -I 7 39-632 39-530 39- 550 39- 662 39- 592 [39 900] 39- 565 [39-449] -I 7 39 8j2- o. +0. +0. — o. +0. — o. — o, — o, +0. — o. +0. — o. — o. fo. +0. 047 04S 061 002 132 062 127 019 069 119 007 095 075 037 033 -o. 060 H-0. 197 ^T =— 1"7 NORMAL EQUATIONS. s. = — 0.022 + 2. 160 (/«' + 3, 420(/f— I. 587(i'i' 1 whence(/«' = + 0,088 + 0.056 -|- 2. 25s (/(?■" — 2, 878,/c— i.iiydt'. da't—^o.ogi + 0, 777 + 3, 420 (/«' — 2, 878 (/«'' + 26, 403 i^dc — o.o^iodt c = + o.i69 + (/£- " E. I — o. 299 + 1 . 942 (/(z' — I. 484 (/(?'■'+ 26. 067 (/it — 1.026a'/ ^T = + o*" 5™ 428.341 + a'/ [ — 0.396 — 0.146 (/a' — 0.080 (/a" — i.o26(/c + 18. 023^/ «' = — 08.195 (circle west) ; a" ^ — o».o8l (circle east); (r^os.183 (+ with circle east). Chronometer No. 1 254, at 2" 7>n.2 chron. time, oi" 5n' 42=.357 + o^.oi 2 slow, losing OM 19 per hour. whence da' =r — o. 007 da" ^ + o. 023 dc = + o. 014 dt ^ + o. 023 31194— No. 97- 82 TELEGRAPHIC DETERMINATION OF LONGITUDES Transits of stars obitrvcd at .Sitit/i2, —0. 045 0.847 I 54 49. 091 48.244 — 0. 067 a Arietis . I 55 10.654 — 0. 307 —0.014 —0. 002 — 0. 366 — u. 032 9-933 2 57. 990 48. 057 + C. 120 f Ceti . . W. 2 I 22.399 —0. 280 -0.009 +0. 007 — 0. 341 — 0. 020 21.756 2 7 9.838 +0 5 48.082 +0.095 L Cassiop. . E. 2 14 II. 740 +0. 493 — 0. 158 — 0. 119 +0. 757 +0. 007 12. 720 2 20 0. 895 +0 5[48.i75] e Ceti . . . 2 16 29. 686 +0.279 —0. 099 +0.014 + 0. 300 + 0.012 30. 192 2 22 18. 345 48. 153 +0. 024 36 H. Cassiop. . 2 21 47.060 +0. 570 —0. 242 — 0. 167 +0. 979 +0. 023 48. 223 2 27 36.490 [48. 267] . . . V Arietis . . 2 26 45. 296 +0. 304 — 0. 147 — 0. 002 +°-3i9 +0- 033 45. 803 2 32 33. 925 48. 122 +0.055 Br. 366 . 2 29 33. 880 +0. 498 -0. 257 — 0. 122 +0.771 +0. 039 34- 809 2 35 22.883 [48. 074] a Arietis 2 39 36. 254 +0.291 —0. 169 +0. 006 +o- 307 +0. 059 36- 748 2 45 24.919 48.171 +0.006 7^ Eridani 2 45 14. 387 +0. 250 — 0. 152 +0. 032 +0. 301 +0.071 14. 889 2 51 3. 102 48- 213 — 0. 036 f Arietis 2 47 6. 256 +0. 303 -0. 186 — 0. 001 +0.318 +f?. 075 6.775 2 52 55- 105 48- 330 -0. 153. 6 Arietis . 2 59 31.529 +0. 300 — 0. 191 +0.001 +0. 31S +0. 101 32-055 3 5 20. 121 48. 066 +0. 1 1 1 f Arietis E. 3 2 45. 779 +0. 302 — 0. 194 — 0. 001 +0.317 +0. 107 46. 310 3 8 35. 523 +0 5 48. 213 — 0. 036 Assuming NORMAL EQUATIONS. : + 0.038 + 1/3' circle W. fo^- + o. 049+ 3. 495 (/«' :+o. loo + ^a" " E. I +0.083 +3.3I5«'«"— 4.240a' 26>n s8».58i + 58».572 + o».oio slow, losing o. 503 dt I o. 745 dt [ 13. 189 dt J circle east). ; 0^.087 per hour. da" = dc = dt = s. — o. 015 + U.031 — o. 009 + u. 001 Dec. 19 (J Piscium E. 7 23 26 33. 246 +0. 277 +0. 035 — 0. 232 38 Piscium . . . 7 23 32 35-916 +0. 255 +0. 040 — 0. 435 a Andromedae . 7 23 35 34- 994 +0. 318 +0. 054 +0. 168 Br. 6 ... . 7 23 42 47- 540 +0. 660 +0. 133 +3-470 a Androraedje • 7 23 45 27- 633 +0. 336 +0.071 +0. 343 K Cassiop. . . . 7 23 59 36. 190 +0.449 +0. 116 + 1.429 TT Andromedse . 7 3 53- 234 +0. 329 +0. 089 +u. 269 e Andromedse 7 5 37-434 +0.318 +0. 088 +0. 173 21 Cassiop. . . 7 II 12. 290 +0. 610 +0. 172 +2.974 f Andromedae . E. 7 14 23. 540 +0. 308 +0. 089 +0.072 t Piscium . . W. 7 30 9- 579 — 0. 278 -0.03s —0. 226 r Piscium 7 38 31-231 — 0. 321 — 0. 076 +0. 200 / Piscium 7 45 3. 040 — 0. 27 1 — 0. 079 — 0. 299 V Piscium 7 46 20. 527 —0.314 —0. 092 +0. 139 1/1 Cassiop. 7 051 4.971 — 0. 498 — 0. 151 +2. 004 38 Cassiop. 6 55 58- 248 -0. 525 — 0. 154 + 2.278 }) Piscium 7 58 31.229 — 0. 291 —0. 082 — 0. 094 T Piscium . 7 I 4 11.473 — 0. 286 —0. 065 — 0. 151

.oi3 slow, losing o'.o86 per hour. Assuming a' = — 0.963 + 27"" 7M66 + fl5? NORMAL EQUATIONS (o=— 0.328 + 3. 942 (/a' — 2.ggTdc— 0.053 a'/" — 0.027 +3-0450^"+ 2. 8i7a'.2 chron. time, oi> 27™ 35=.529 ± os.014 slow, losing o».o7o per hour. Assuming a' = — o. 293 + da' circle W. a'' = — o. 162 + ^a" " E- c = + 0. 452 + i/ 29™.! chron. time, o'' 27™ 37". 173 -[- o».oo8slow, losing os.073 per hour. Jan. 4 f Piscium W. 29 34- 913 — 0. 278 — 0. 009 — 0. 050 — 0. 464 — 0. 048 34- 06 \ 57 13. 069 +0 27 39.005 + 0. 052 44 H. Cephei . . 35 9- 280 — 0. 764 — 0. 170 + 1.030 —2. 429 — 0. 040 6.907 I 2 46. 261 [39- 354] . . . r Piscium 37 57-117 — 0. 321 — 0. 093 +u. 044 —0-529 —0. 036 56. 182 I 5 35-211 39. 029 + 0.028 / Piscium . . . 44 28.456 — 0. 271 — 0. 104 — 0. 066 — 0. 460 —0. 026 27. 529 I 12 6. 590 39- 061 — 0. 004 V Piscium 45 46. 166 -0.314 — 0. 121 +0. 030 -u. 515 — u. 024 45. 22:! I 13 24. 324 39-.I02 — 0.045 fli Ceti. . . 50 52. 496 -0.251 — 0. 097 — 0. no -0. 466 — 0. 017 51- 555 I 18 30. 670 39- 115 — 0. 058 38 Cassiop. 55 24.829 -0.525 — 0. 186 +0. 500 -■•325 — L). on 23. 282 I 23 2. 169 [38. 887] , V Piscium . . W. 57 56.849 — 0. 291 —0. 094 — 0. 021 — 0. 476 — 0. 007 55- 960 I 25 35. on +0 27 39.051 + 0. 006 I' Piscium . . E. 8 1. 866 +0. 274 0. 000 — 0. 062 +0. 422 +0. 007 2.507 I 35 41. 676 +0 27 39. 169 — 0. n2 Piscium II 54-517 +0. 281 0. 000 — 0. 047 + 0. 425 +0.013 55- 189 I 39 34- 366 39- 177 — 0. 120 F Cassiop. . 18 47. 640 +0. 455 0. 000 +0. 363 +0. 929 +0. 023 49.410 I 46 28. 508 [39- 098] y Arietis . . . 19 49- 103 +0. 299 0. 000 — 0. 005 +0. 443 +0. 024 49. 864 I 47 28. 689 38. 825 + 0. 232 li Arietis 20 53. 240 +0. 302 0. 000 +0. 002 +0. 448 +0. 026 54. 018 I 48 33- 102 39. 084 — 0. 027 50 Cassiop. . . 26 20. 840 +0. 559 0. 000 +0. 606 + i-35> +0. 034 23- 390 I 54 2. 5n [39- 121] . . . a Arietis . . E. 33 17- 896 +0. 307 0. 000 +0. 014 +0. 456 +0. 044 18.717 2 57. 722 +0 27 39.005 + 0. 052 + 2.32ia'c— 0.0360'/') whence a'a' = -\- 2.022da" — 2. 170 at — 0.554^'/ NORMAL EQUATIONS o^ — 0.042 + 2. guda' + o. 066 — 0.078 + 2. 321 fl'a'' — 2. I'jo da" -\- i<).:^6:^dc — 0.771a'/ f — u. 126 — o.oTfi da' — o. ^ii\da" — o.yyi dc -\- 11. 801 dt ) = — o".227 (circle west) ; u" = — o''.239 (circle east) ; c = o=.440 (+ with circle east). Chronometer No. 1254, at 1^ 2"".8 chron. time,o'' 27™ 39".o57 -(- o'.020 slow, losing 0^086 per hour Assuming a' = — o. 242 + da' circle W. a" = — o. 208 + da" " E. c =: + o. 44l+(/c " E. /\T = + o"! 27"" 39».048 + (*■. > da" = dc =: dt = + 0.015 — 0.031 — O.OOI + 0.009 IN MEXICO, CENTRAL AMEUIOA, TUE WEST INDIES, ETC. 91 Transitsof stars observed at Port Plata, San Domingo, by Lieut. Charles Laird, U. S. Navy, with transit No. 1304, to determine the crorection of sidereal cnronometer A'egiis No. 12^4- Date. Name of Star. Ceti. . . . I 39 27. 666 +0. 280 - 0. 096 — 0. 027 +0. 388 +0. 007 28.218 2 7 9. 602 41 384 - 0. 147 y Trianguli . . I 43 3-881 +0. 329 — 0. 114 +0.037 +0. 460 +0.013 4. 606 2 10 45-937 41 331 — 0. 094 ft Arietis . I 44 17-634 +0. 300 —0. 104 — 0. 001 +0. 407 +0.015 18.251 2 II 59.827 41 576 - 0. 339 t Cassiop. E. I 52 17. 090 + 0.491 -0. 174 +0. 246 +0. 979 + 0. 027 18.659 2 19 59-931 +0 27[4i 272] 6 Ceti . . W. 2 6 9.681 — 0. 266 -f-o. 004 — 0. 035 -0. 424 +0. 047 9.007 2 33 50-261 +0 27 41 254 — 0.017 Br. 366 2 7 42. no — 0. 496 0.000 +0. 195 — I. lOI -f 0.049 40. 757 2 35 22.025 [41 268] 35 Arietis ' 2 9 18.846 -0.31S —0. 004 +0.015 -0. 477 + 0.052 18. 117 2 36 59- 346 41 229 + 0.008 p, Ceti . 2 II 18. 704 — 0. 283 — 0. 006 — 0. 018 — 0. 430 +0. 055 18.023 2 38 59- 257 41 234 + 0.003 41 Arietis 2 15 49-633 -0-315 — 0. 014 -|-o. 014 -0. 475 +0.062 48. 905 2 43 30. 107 41 202 + 0.03s y Persei . . 2 29 9. 380 — 0. 394 — 0. 025 +0- 093 -0. 706 +0. 082 8.430 2 56 49. 656 [41 226] f Arietis w. 2 40 53. 801 — 0. 302 -f 0. 004 -|-0. 002 —0.453 +0. 099 53-151 3 8 34- 427 +0 27 41 276 - 0. 039 Assuming a' a" c AT NORMAL EQUATIONS, -o. 160 + i:. iSoo'a'' — i.i<^odc — I. 015 (// ~1 whence i/a' = + 0.073 -0.027 + r. 580 «'«'•'+ \.<)OT,dc — 0.755* '. r/rt" ^ + o. 023 : + 0.407 + (/ 27"'43''.38i -J- o'.oi i slow, losing 0^.089 per hour Assuming a' = — 0.115 + *?' circle W. a"^ — o. 200 + *2" " E. e = + o. 390 + *■ /:^T = + o* 27>" 43°-38o + dt. a' E. whence"*?' = + 0.012 da" = — o. 065 * =^ + o. 008 * =: + o. 002 92 TELEGRAPHIC DETERMINATION OF LONGITUDES Transits of stars observed at Curacao, Hist Indies, by Lieut. Charles Laird, U. S. A\niy, nith transit No. 1504, to dcftriiiine the correction of sidereal chronomtter Negus No. J2j4. Date. Name of Star. V Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate. Seconds of corr. transit. R.A. Chronometer correction. V. 1S90. Jan. 20 17 Tauri . W. 7 h. m. s. 3 2 53.323 s. —0- 303 s. +0. 090 s. — 0. 05 1 J. — 0. 498 -0. 183 .f. 52- 378 h. m. s. 3 38 20. 297 h. +0 m. s. 35 27.919 s. — 0.040 V Tauri .... 7 3 5 29.476 -0. 303 +0- 099 —0.050 — 0. 498 — 0. 177 28. 547 3 40 56.428 27.881 — 0.002 1 Tauri . . . 7 3 19 7-891 —0. 289 +0. 123 0.000 — 0. 466 —0. 150 7. IC9 3 54 34- 948 27-839 + 0.040 V Tauri . . . 7 3 21 50-971 — 0. 283 -(-0. 122 -\-o. 026 -0.458 — 0. 144 5°- 234 3 57 18.128 27. 894 — 0.015 oi Eridani . . • 7 3 31 2.514 — 0. 269 -|-o. 116 +0. 076 — 0. 460 — 0. 127 1.850 4 6 29.711 27.861 + 0.018 y Tauri . . . 7 3 38 4- 827 -u. 293 -|-o. 122 -0. 014 -o- 473 — 0. Ill 4.058 4 13 31.900 27. 842 + 0.037 d Tauri 7 3 41 8. 320 -0. 295 -fo. 119 — 0. 022 — 0. 477 —0, 105 7.540 4 16 35- 345 27.805 + 0-074 Gr. 848 7 3 58 38- 970 — 0. 510 +0. 144 -0-833 —I. 851 —0. 069 35-851 4 34 3-810 [27- 959] f- Eridani . 7 4 4 32. 891 -0. 273 +0. 065 +0. 062 -0. 457 — 0. 057 32.231 4 40 0. 186 27- 955 — 0. 076 u. Camelop. . W. 7 4 7 41. 600 — 0. 411 +0.08 — 0. 458 —1.128 — 0. 050 39- 640 4 43 7- 484 +0 35[27.S44] 22 Camelop. H. E. 7 5 31 16.430 +0- 434 — 0. 213 — 0. 849 -f I. 180 +0. 121 17. 103 6 6 44. 826 +0 35[27. 723] . . . n Geminorum 7 5 32 46- 050 +0. 501 — 0. 154 — 0. 070 +0.451 +0. 124 46. 702 6 8 14.638 27- 936 — 0. 057 ;« Geminorum 7 5 40 50. 146 +u. 301 -0. 179 — 0. 070 +0.451 +0. 140 50. 789 6 16 18.731 27.942 — 0.063 8 Monocerotis 7 5 42 28. 193 -f-o. 282 — 0. 170 -fo. 046 +0.417 +0. 143 28.911 6 17 56. 760 27. 849 + 0.030 V Geminorum 7 5 46 57-731 +0. 298 — 0. 186 — 0. 054 +0. 443 +0. 153 58.385 6 22 26. 260 27. 875 + 0. 004 23 H. Camelop. 7 5 52 2.350 +o- 603 -0- 383 -I-S37 +2.323 +0. 163 3-219 6 27 31. 196 [27-977] f^ Canis Majoris . 7 5 54 58-699 +0- 250 — 0. 160 -|-0, 221 +0.451 +0. 169 59- 630 6 30 27. 469 27- 839 + 0. 040 IS Monocerotis 7 5 59 27.030 +0. 287 -0. 182 +0.013 +0. 422 +0. 178 27. 748 6 34 55- 620 27.872 + 0. 007 ■5 Geminorum E. 7 6 3 38-731 -|-o. 290 — 0. 181 — 0. 006 +0. 427 +0. 187 39- 448 6 39 7-330 +0 35 27.882 — 0.003 Assuming a' = AT NORMAL EQUATIONS, fo^ — o. 092 -j- 2. 953 (Aj' -f- ^. 01-] dc J +0.040 -f 3. 440fl'fl''' — ^.o-]o dc 1 -|-o. 018 + 3. 017 at\ y +0.122 — 0.864^3' — 0.6230'^'' — I. i30fl?^+ 15. 680 a"; J a' r=-\- o=.229 (circle west) ; a" ^ -\- o».356 (circle eastj ; c -=o».436 (+ with circle east). Chronometer No. 1254, at 4'" 32™ .3 chron. time, o'' 35™ zy'.Syg + o=.oo7 slow, losing os.123 per -{- o. I()t -\- da' circle W. + 0.377 + ^0:" " E. + o.445-ffl'^ " E. + oi' 35™ 278.885 + dt O. 864 dt '] o. 623 dt I whence da' = - da" = - dc =- dt =- hour. s. - o. 038 -0.021 - o. 009 - o. 007 Jan. 21 P Ceti . . . 36 H. Cassiop V Arietis . d Ceti . . Br. 3:6 y Ceti . . /i Ceti . . a Arietis. 47 Cephei, H S Arietis . . f Arietis . Tauri . . f Tauri . . / Tauri . . Gr. 716 . y Camelop. H 27 Tauri . . W. I 46 I 52 I 57 I 58 1 59 2 2 2 3 2 9 2 16 i: 29 2 33 2 43 2 45 2 49 2 57 3 3 3 7 48. 229 — 0. 284 -0. 025 +0.018 -0. 433 — 0. 064 47-441 6. no —0. 463 — 0. 023 — 0. 686 —1.414 -0. 055 3-469 4.046 —0. 300 — 0. 01 1 — 0.042 — 0. 461 — 0. 046 3.186 20. 274 — 0. 276 — 0. 009 +0.051 -0. 429 -0. 043 19. 568 53-214 —0.419 — 0. 013 — 0. 5 1 1 — I. 114 — 0. 040 51. n7 5-654 — 0. 282 — 0. 010 +0. 039 — 0. 429 —0. 036 4-936 29. 460 — 0. 287 — 0. 010 +0. 01 1 -0. 435 —0. 034 28. 707 54- 979 —0. 292 — 0. 021 — 0. on — 0. 443 — 0. 022 54- 190 2.180 — 0. 582 — 0. 082 -1-154 —2. 246 — 0. on 58. 105 48. 646 +0. 297 ■ +0. 062 — 0. 025 +0.412 +0.014 49. 406 2. 980 +0. 299 +0. 069 — 0. 029 +0.416 +0. 020 3-755 22. 026 +0. 286 +0. 077 +0.011 +0- 393 +0. 039 22. 832 40. 803 +0. 286 +0.077 +0. 009 +0. 394 +0. 043 41. 612 16. 389 . +0. 290 -|-o. 078 — 0. 001 +0.398 +0. 049 17. 203 5.070 +0- 392 +0. 097 —0.314 +0. 853 +0. 063 6. 161 13-520 +0.449 +0. 095 — 0. 486 + I-195 +0. 07 s 14. 848 5.729 +0- 303 +0. 053 — 0. 041 +0. 425 +0. 082 6.551 2 22 17. 2 27 34. 2 32 33- 2 33 50- 2 35 21. 2 37 35- 2 38 59- 2 45 24- 2 51 28. 3 5 «9- 3 8 34. 3 18 53- 3 21 12. 3 24 47- 3 32 36- 3 38 45- 3 42 36- 945 285 522 082 348 435 073 572 478 834 243 236 097 602 630 242 994 +0 +0 +0 +0 35 30- [30. 30- 30- [30- 30- 30- 30. 35[30- 35 30. 30. 30. 30- 30- [30. [30. 35 30- 504 816] 336 514 231] 499 366 382 373] 428 488 404 485 399 469] 3941 443 — o. 067 + + + O. lOI o. 077 o. 060 0.071 0.05s o. 009 o. 051 0.033 0.048 0.038 o. 006 NORMAL EQUATIONS. Assuming a' = + o. 248 -\- da' circle W. f = + o. 055 +4. 3l9(/a' + 4. 558i/ 35m 38. 247 -|- (//. [ —0.075 — I. 158 «'«' — 0.810 rfo"— I. 152 l3«.85o + aC/. whence da' da" — o. 029 + o. 201 dc = — o. 025 dt = + o. 001 96 TELEGEAPHIC DETERMINATION OP LONGITUDES Transits of stars obsen'ed at La Guayra, Vcnc-Aiela, by Lieut. Charles Laird, U. S. Navy, with transit No. 1304, to determine the , nometer Negus No. 12^4. rection of sidereal chro- Date. Name of Stai. u E. ui -a rt .a 6 "A Transit over mean of threads. Flexure and in- equality of pivots. Level. Azimuth. Aberra- tion and colli- mation. Rate. Seconds of corr. transit. R.A. Chronometer correction. V. 1890. Feb. 9. 19 H. Camelop. . h. m. s. 4 20 13.240 J. +0. 549 s. ' -0.033 J. -J- 954 s. +0. 804 J. — 0. 056 s. 12.550 h. m. s. 5 4 27.231 h. m. s +0 44[H 681] s. 7 Orionis . . . 4 34 41- 183 +0.276 — 0. 037 +0. 090 +0. 152 — 0, 042 41. 622 5 18 56.766 15 144 + 0. 122 Gr. 966 .. . 4 40 47- 350 +0. 472 — 0. 023 -1.380 +0. 586 — 0. 037 46. 968 5 25 2.589 [■5 621] a Leporis . . 4 43 37- 090 +0. 261 — 0. 007 +0. 199 +0. 160 — 0. 034 37- 669 5 27 52.916 15 247 + 0.019 a Orionis . . . 4 48 57- 794 +0. 276 0. 000 +0.091 +0. 152 — 0. 029 58. 284 5 33 i3-5'3 15 229 + 0.037 a Orionis. s s 57.380 +0. 285 — 0. 017 +0.023 +0. 153 —0.013 57.811 5 49 13-129 «5 318 — 0. 052 66 Orionis . . . S 14 54. 100 + 0.282 — 0. 033 +0. 045 +0. 152 — 0. 004 54- 542 5 59 9- 856 15 314 — 0.048 V Orionis . . . E. 5 17 I- 957 +0. 292 — u. 039 — 0. 030 +0.157 — 0. 003 2-334 6 I 17.729 +0 44 15 395 — 0. 129 iU Geminorum W. 5 32 3-959 — 0. 300 +0. 020 — 0. 140 — 0. 208 +0. on 3- 342 6 16 18.621 +0.44 15 279 — 0.013 8 Monocerotis 5 33 41-726 — 0. 282 +0. 026 +0. 065 — 0. 193 +0. 012 41-354 6 17 56.658 15 304 — 0,038 V Geminorum 5 38 11.466 — 0. 297 +0. 045 — 0. 112 — 0. 205 +0.017 10. 914 6 22 26. 170 15 256 + 0. 010 8 Lyncis . . 5 43 25.471 — 0. 374 +0. 079 — I. 020 — 0. 403 +0. 021 23- 774 6 27 39.036 ['5 262] P Canis Majoris. 5 46 11.959 — 0. 256 +0. 060 +0- 375 — 0. 208 +0. 024 "-954 6 30 27. 318 15 364 — 0. 098 y Geminorum 5 47 7-007 — 0. 293 +0. 070 — 0. 067 — 0. 200 +0.025 6.542 6 31 21.752 15 210 + 0.056 15 Monocerotis . 5 50 40. 777 — 0. 287 +0.076 +0. 007 — 0. 195 +0. 028 40. 406 6 34 55- 538 15 132 + 0. 134 43 Camelop. . . W. 5 57 38- 864 —0.414 +0. 126 -1.487 -0. 536 +o- 635 36. 587 6 41 51. 964 +o.44[i5 377] • • • NORMAL EQUATIONS. Assuming a' ^ + 0. 418 + (&' circle E. f = + 0. 030 + 3. 598a'rt' — 2.4363^-+ o.2'jldt] whence y Lieut. J. A. Morris — Conlinucd. 101 Corrections, Date. Number and catalogue. Apparent dcclinalion. Half sum of declina- tions. Latitude. Micrometer, Level. Ref. 1889. / // / 1/ / // // // / // // Jan. 16 B.A.C. 1558 1579 +41 5 2.25 — 4 48 27. 73 + 18 8 17. 26 -|- 26. 66 + 1-53 +0.01 + 18 8 45-46 0-73 1558 1593 +41 5 2-25 — 4 36 14. 82 + 18 14 23.72 - 5 39- 77 + 1-53 — 0. II + 18 8 45-37 0.82 1663 1682 +37 16 51.81 — I 4.39 + 18 8 23-71 + 20.74 + 0.08 +0. 01 + 18 8 44-54 1.65 1692 1734 + 17 51 53-75 + 18 27 33.00 + .8 9 43-38 — 59. 18 + 0.92 — 0,02 + 18 8 45. 10 1.09 1780 1830 — 2 39 57-22 +39 8 32.38 + 18 14 17-58 - 5 30-33 + 0-53 —0. 11 + 18 8 47.67 1.48 1780 1845 — 2 39 57-22 +39 6 53,37 + 18 13 28.08 — 4 41-49 + 0.69 —0.09 -fi8 8 47.19 1. 00 1956 2009 + 19 48 47.16 -(-16 10 30.59 + 17 59 38.88 + 9 4-02 + 3-36 +0. 18 + 18 8 46. 44 0. 25 2057 2110 + 3 49 5-74 +32 31 59- °> + 18 10 32.38 — I 46. 23 + 1-53 — 0. 04 + 18 8 47.64 1-45 2144 B.A.C. 2170 Mean (31 de + 7 39 23.85 +28 21 32. 76 terminations) .... + 18 28.30 + 8 16.3s + 1-07 +0.17 + 18 8 45-89 0. 30 + 18 8 46. 19 +0. 12 Latitude of observing station, Salina Cruz, from zenith telescope observations by Lieut, J. A. A^orris. Corrections. Number and catalogue. Apparent declination. Half sum of declina- tions. Latitude. Date. Micrometer. Level. Ref. 1889. Feb. 18. B.A.C. 2022 2047 + 9 +22 / // 58 49- 19 34 8. 37 + .6 / 16 // 28.78 / — 6 // 21. 24 // — 0.08 // —0. 12 + 16 / 10 // 7-34 // 0. 60 2088 2110 — +32 12 43-75 32 I. 61 + 16 9 38-93 + 29.48 — 0.84 +0.01 + 16 10 7.58 0.84 2211 2238 + 8 +23 42 8. 52 43 58. 20 + 16 13 3-36 — 2 51. 60 - 2.52 —0.06 + 16 10 g. 18 2-44 2304 2313 + 9 +22 17 51.68 48 7. 25 + 16 2 59-46 + 7 3-67 + 4.58 +0.14 + 16 10 7-85 I. II 2330 2362 + '6 + 16 6 21. 17 20 42. 68 + 16 '3 31.92 — 3 23-85 - 2.37 —0. 07 + 16 10 5-63 I. II 2423 2444 -)-20 + 11 39 5 -.03 53 6.70 + 16 16 5-86 — 6 2.36 -|- 2. 06 —0, 12 + 16 10 5-44 1.30 Feb. 19. 1665 1681 + 3 +28 26 5. OS 30 45.26 + 'S 58 25. 16 + 11 38.55 + 5-49 +0.23 + 16 10 9-43 2. 69 1828 1852 + 17 + '4 41 8.17 16 16. 66 + •5 58 42.42 + 11 25.78 — 0.31 +0-23 + 16 10 8.12 1-38 1880 B.A.C. 1907 + 19 + 12 43 34- 04 47 42-59 + 16 15 38-32 - 5 34-46 + 0.23 —0. II + 16 10 3-98 2.76 102 TELEGRAPHIC DETEEMINATION OF LONGITUDES Latitude of observing station, Salina Cruz, from zenith telescope observations by Lieut. J. A. iV(7r;7J-— Continued. Date. Feb. 19 Number and catalogue. Feb. 20 B.A.C. 1934 2012 1986 2012 2622 2047 2304 2313 2330 2362 2423 2444 2493 2522 1689 1 701 1725 1772 1792 1810 1880 1907 1934 2012 Apparent declination. 2022 2047 2304 2313 2330 2362 2423 2444 2493 2522 2493 B.A.C. 2526 o / // +19 41 + 12 35 + 19 48 +12 35 + 9 58 +22 34 + 9 17 +22 48 + 16 6 + 16 20 +20 39 + 11 53 +27 8 + 5 30 + 16 35 + 15 46 + 3 12 +29 9 + 16 28 +16 2 + 19 43 + 12 47 + 19 41 + 12 35 Half sum of declina- tions. 1986 +19 2012 +12 35 + 9 58 +22 34 + 9 17 +22 48 + 16 6 + 16 20 +20 39 + 11 53 +27 8 + 5 30 +27 8 + 5 29 Mean (28 determinations) 25.91 0.63 50-99 0.63 49-15 8.40 51.64 7.27 21.09 42.67 5-04 6.68 27-37 24.49 56.98 40.76 16. 41 3-59 27.36 8.40 34-01 42-54 25-88 0.59 47.61 0-59 49.10 8.42 51-59 7.27 21.07 42.65 5-04 6.64 27-39 24. 42 27-39 3-05 O / If + 16 8 13.27 + 16 II 55-81 + 16 16 28.78 + 16 2 59.46 + 16 13 31-88 Corrections. Micrometer. / // + I 51-05 — I 51-40 — 6 17.31 + 7 10.43 — 3 27.43 + 16 16 5.86 - 5 55.75 + 16 19 25.93 + 16 II 18.87 -|-i6 10 40.00 + 16 IS 17.! + 16 15 38.28 + 16 8 13.24 + 16 II 54.10 + 16 16 28.76 + 16 2 59.43 + 16 13 31.86 + 16 16 5.84 + 16 19 25.90 -f-i6 18 45.22 — 9 20. 01 — I 9.65 o 31.76 5 IS- IS — 5 32-46 -f- I 52.02 I 48.09 + o. 15 Level. + 0.15 + I- 07 -3.66 + 0.76 — o. 92 0.61 — 0.84 I. 15 + 2.59 + 0.38 — 6 24. 48 + 7 10.36 3 26. 05 5 58- 44 9 20. 14 8 37.38 — 0.15 o. 92 + 0.23 0.31 0.31 Ref. +0. 04 — 0. 03 — 0. 13 +0. 14 — 0. 07 — 0. 12 — 0. 19 — 0. 02 — 01 -0. II — II +0 04 — 0. 04 — 13 +0 14 - 07 — 12 — 19 — 17 Latitude. o / // -)-i6 10 4.51 + 16 10 5.45 + 16 10 7.68 + 16 10 8.81 + 16 10 5. 14 -|-i6 10 9.07 -)-i6 10 5. 12 + 16 10 8.36 + 16 10 7.08 + 16 10 5. 18 -)-i6 10 6.09 + 16 10 5.30 + 16 10 6. 12 -|-i6 10 4.00 -(-16 10 9.01 -)-i6 10 7. 19 + 16 10 7.51 + 16 10 5.26 + 16 10 7.36 // 2.23 I. 29 0-94 2.07 1.60 2.33 I. 62 1. 62 0.34 1.56 0.65 1.44 o. 62 2.74 2. 27 0.45 0.77 1.48 o. 62 -|-i6 10 6.74 j-o. 22 IN MEXICO, OEJSTliAL AMEKIOA, THE WEST INDIES, ETC. Latihide ofoherring staiion, San Juan del Surjrom zenith telescope obsei-vations by Lieut. J. A. Non-is. 103 Date. Number and catalogue. Apparent declination. Half sum of declina- tion,s. Corrections. . Micrometer. Level. Ref. 1889. Mar. 31 IS. A. C. 3769 3838 / // + 6 41 45. 64 + 16 2 6.20 / // + 11 21 55.92 — 6 56. 30 / + 5-49 / — 0. 14 3838 3862 + 16 2 6.20 + 6 38 9.30 + 11 20 7.75 — 5 6-35 + 5-49 — 0. 09. Apr. I 3398 3406 + 9 27 25. 85 + 12 58 21.58 + 11 12 53.72 + 2 11.37 -0-53 +0.04 3663 3671 — I 9 37-0O +23 46 7-38 + 11 18 15.19 - 3 9-86 — 0.84 — 0.06 3684 3691 + 3 4 II- 18 + 19 28 29.31 + 11 16 20.24 - I 13-78 — 2. 21 — 0.03 3711 3735 — 3 26 20.35 +26 4 52. 15 + 11 19 15.90 — 4 8. 42 + 0.08 —0.08 37" 3751 — 3 26 20. 35 +26 5 31.86 + 11 19 35.76 — 4 z8. 95 + 0.08 —0.09 3769 3838 + 6 41 45.69 + i6 2 6.29 + 11 21 55.99 — 6 52.03 + 2.52 — 0. 14 3838 3862 + 16 2 6.29 + 6 38 9-34 + 11 20 7.82 — 5 3- 32 + 0.08 ' — 0. 10 Apr. 2 3398 3406 + 9 27 25.41 + 12 58 21.63 + 11 12 53.52 + 2 10. 75 + 0.53 +0.04 3415 3475 + 8 34 29.68 +13 54 6.08 + 11 14 17.88 + 46. 63 + I. 22 +0. 02 3534 3544 + 15 32 1.64 + 7 6 14.94 + 11 19 8.29 — 4 3-66 + "-53 —0.08 3663 3671 — I 9 37- 00 +23 46 7-49 + 11 18 15.24 — 3 17-04 + 7-71 — 0. 07 3684 3691 + 3 4 II. 20 + 19 28 29.41 -|-li 16 20.30 — I 14. 19 - 1-83 — 0. 03 3711 3735 — 3 26 20.37 +26 4 52.28 + 11 19 15.96 — 4 II. 04 + 0-23 —0.08 37" 3751 — 3 26 20. 37 +26 5 31.99 + 11 19 35.81 — 4 30- 12 + 0-23 — 0. 09 3769 3838 + 6 41 45. 72 + 16 2 6.38 + 11 21 56.05 — 7 13-18 +25.71 — 0. 14 3838 3862 + 16 2 6.38 + 6 38 9. 38 + U 20 7.88 — 5 29. 09 + 28. 38 — 0. II 3956 3965 —12 35 36.47 +34 49 41-92 + 11 7 2.72 + 8 1.27 0. 00 +0, 16 3982 B. A. C. 399S Mean (20 < + 7 8 59. 55 +15 II 28.52 eterminations) . . . . +11 10 14.. 04 + 4 51-96 — 0.08 +0. 10 Latitude. o / // + 11 15 4-97 + 11 15 6.80 + 11 15 4.60 + 11 IS 4-43 + 11 15 4.22 + 11 15 7-48 + 11 IS 6.80 + 11 15 6.34 + 11 15 4-48 + 11 15 4.84 + 11 15 5-75 + 11 15 5.08 + 11 IS 5-84 +11 15 4-25 +11 15 5.07 + 11 15 5-83 + 11 15 8.44 + 11 15 7-o6 + 11 15 4-15 -)-ii 15 6.02 + 11 15 5-63 104 TELEGRAPHIC DETERMINATION OP LONGITUDES Laiihide of olncrvim; station, St. Nicolas Mole, from zenith telescope observations by Lieut. J. A. Norris. Date. Number and catalogue. Apparent declination. Half sum of declina- tions. Corrections. Micrometer. Level. Ref. 1889. / // / // // // // Dec. 10 B.A.C. 8237 8328 +43 — 4 43 10 37-51 5-95 + 19 46 45-78 + 2 28. II — 0.08 +0.05 8350 8370 +26 + 12 30 47 2.04 0. 61 + 19 38 31-33 + 10 40.40 + 1-75 +0. 16 100 145 +43 — 4 47 12 15-77 2.94 + 19 47 36.42 + I 37-55 + 0.15 +0.03 469 556 + 17 +21 53 43 53-08 44.84 + 19 48 48.96 + 25.14 + 0-92 +0.01 625 649 + 2 +37 13 20 50.09 17.09 + 19 47 3-59 + 2 11.37 + 0.76 +0.04 Dec. II 8203 8227 + 21 + 17 53 47 31.02 27.50 + 19 50 29. 26 • — I 14. 06 + 0.31 —0. 02 8237 8328 +43 — 4 43 10 37-51 6. 02 + 19 46 45-75 + 2 28. 04 + 2.06 +0.04 8350 8370 +26 + 12 30 47 2.02 0.56 + 19 38 31.29 + 10 44.74 - 1-75 +0. i6 170 214 +20 + i8 50 58 5.68 38-31 i-i9 54 22. 00 - 5 6. 56 + 0.08 -0.08 223 250 + 16 +23 20 I 46.51 57.18 + 19 41 21.85 + 7 51-69 — 0.08 +0. 12 307 336 +20 + '9 53 4 2-54 16.91 + 19 58 39-73 — 9 26. 96 + 2.67 — 0. 14 384 425 - 3 +42 4 53 52-53 18.59 + 19 54 13-03 — 4 54- 50 - ..76 — 0. 09 469 556 + 17 +21 53 43 53-09 44.86 + 19 4S 48.98 + 26.80 — 0. 76 0. 00 580 615 +36 + 2 42 34 46.55 8.81 + •9 38 27.68 + 10 48.05 + 1.60 +0.19 625 649 + 2 +37 13 20 50.04 17. 20 + 19 47 3. 62 + 2 14.89 — 2. 21 +0.04 67s 745 +29 + 10 47 6 16. 20 38.62 + >9 56 57-41 — 7 44-32 + 0.92 —0. 12 675 755 +29 + 10 47 4 16. 20 8.21 + 19 55 42. 20 — 6 29. 23 + 0.99 —0.09 Dec. 12 62s 649 + 2 +37 13 20 49-98 17.29 + 19 47 3-64 + 2 13-09 - 1-37 +C.04 Dec. 13 307 336 +20 + 19 53 4 2.49 16.85 + 19 58 39-67 — 9 26. 28 + 2. 06 — 0. 14 384 425 - 3 +42 4, S3 52.70 18.75 + 19 54 13-03 ■ — 4 57 95 + 1-98 — 0.09 469 556 + 17 +21 53 43 53-03 44.86 + 19 48 48.95 + 25.56 — 0. 99 +0.01 5S0 B.A.C. 615 +36 + 2 42 34 46.67 8.66 + 19 38 27.67 + 10 4c oS -r 3-97 +c. 18 Latitude. o / // + 19 49 13.86 + 19 49 13.64 + 19 49 14. 15 + 19 49 15.03 + 19 49 15.76 + 19 49 15.49 + 19 49 15.89 + 19 49 14-44 + '.9 49 16.68 + 19 49 15.02 + 19 49 17.52 + 19 49 16.34 + 19 49 13- ' + 19 49 13.87 + ig 49 15.40 + 19 49 15.31 + 19 49 16.97 + 19 49 13-53 1.32 0.07 0.80 0-53 0-93 o. 52 + 19 49 15.44 I 0.48 + 19 49 13. 58 1.38 + 19 49 15.30 0.34 I. 72 o. 06 2.56 1.38 1.07 1.09 0.44 0.35 1-43 + 19 49 12.50 2.46 IN MEXICO, OBNTKAL AMERICA, THE WEST INDIES, ETC. Lafitiitii- of observing station, St. Nicolas Mole, from zenith telescope observations by Lieut. J. A. jVorra— Continued. 105 Date. Number and Catalogue. Apparent declination. Half sum of declina- tions. Corrections. Latitude. Micrometer. Level. Ref. v. 1889. / // / // / // // 1/ / // // Dec. 13 B. A. C. 675 745 +29 + 10 47 6 16. 29 38.5s + 19 56 57.42 - 7 41. J5 — I. 22 — 0. 12 + 19 49 14-93 0.03 675 755 +29 + 10 47 4 16. 29 8.13 +19 55 42. 21 — 6 25.10 — 1.22 —0. 10 + 19 49 15-79 0.83 808 867 +21 + 17 29 49 6.84 29.04 + 19 39 17.94 + 9 54.31 + 0.76 +0. IS + 19 49 13.16 1.80 Dec. 14 170 214 +20 + 18 50 58 5-54 38. 16 + 19 54 21.85 -5 8.76 + 1.37 —0.08 + 19 49 14-38 0.58 223 250 + 16 +23 20 I 46.34 57.08 + 19 41 21. 71 + 7 50. 38 + 1.22 +0. 12 + 19 49 13-43 1-53 307 336 +20 + 19 53 4 2.44 16.80 + 19 58 39.62 — 9 25. 24 + I. 14 —0. 14 + 19 49 15-38 0.42 580 615 +36 + 2 42 34 46.72 8.57 + 19 38 27.65 -|-io 46.60 — 0.08 +0.18 + 19 49 14.35 0. 61 625 649 + 2 +37 13 20 49. 80 17.40 + 19 47 3-60 + 2 8.76 + 0.30 +0.04 + 19 49 12-70 2.26 67s 745 +29 + 10 47 6 16. 31 38-49 + 19. 56 57.40 — 7 45. 14 + 1.98 —0. 12 + 19 49 14.12 0.84 675 755 +29 + 10 47 4 16. 31 8.07 + 19 55 42.19 — 6 29. 30 ■y 1.98 —0. 10 + 19 49 14-77 0. 19 808 867 +21 + 17 29 49 6.83 29. 02 + 19 39 17.93 + 10 0.38 — 2.75 +0.15 + 19 49 15.71 0.75 904 929 +31 + 8 29 28 29. 18 4.57 + 19 58 46-88 — 9 32. 54 + 0,76 -0. IS + 19 48 14.95 0. 01 986 999 + 19 +20 18 38 35.41 9.74 +19 58 22.58 - 9 7-54 — 0.23 —0.14 + 19 49 14.67 0. 29 Dec. 15 307 336 +20 + 19 53 4 2.37 16.75 +19 58 39.56 — 9 26. 62 + 1.60 — 0. 14 + 19 49 14.40 0. 56 469 556 + 17 +21 53 43 52-94 44.80 +19 48 48.87 -|- 29. 28 — 2. 29 -|-o. 01 + 19 49 15.87 0.91 Dec. 16 904 929 +31 + 8 29 28 29.24 4.41 + 19 S8 46.83 -- 9 32- 13 + 0.38 -0. IS + 19 49 14.93 0.03 986 999 + 19 -)-20 18 38 35.36 9.70 +19 58 22.53 — 9 5- 54 — 0. 61 -0.13 + 19 49 16.25 I. 29 1040 1087 +27 + 12 12 33 46. 61 30.76 +19 53 8.69 - 3 52-09 0. 00 — 0.05 + 19 49 16.55 1-59 1 132 1202 +33 + 6 36 12 43.33 ID. 61 + 19 54 26.97 -5 11.38 + 1.45 —0.08 + 19 49 16.96 2.00 1285 1322 + 5 +34 14 18 6. 10 1-85 + 19 46 3.98 + 3 10.89 — 0.76 +0.05 + 19 49 14. 16 0.80 1346 1367 + 17 -)-22 17 33 0.57 47.60 + 19 55 24.09 — 6 7.18 - 3-05 — 0. 09 + 19 49 13-77 1. 19 1356 B.A.C. 1367 + '7 +22 II 33 17.02 47.60 + 19 52 32 3" -3 15.65 - 3- OS —0.05 + 19 49 13-56 I. 40 106 TELEGKAPHIO DETERMINATION OF LONGITUDES Latiliidi- of niiseyviiii; station, St. Nico/as Mole, from zenith tekscoffe observations by Lieut. J. A. Norris — Continued. Corrections. Number and catalogue. Apparent declination. Half .sum of declina- tions. Latitude. V. Micrometer. Level. Kef. 1889. / 1/ / ff 1 /r // It / // // Dec. 16 B. A.C. 1429 1445 — 3 34 +43 9 44-03 18.63 + 19 47 17-30 + I 59-94 — 0.92 +0.04 + 19 49 '6. 36 1.40 1476 1508 +37 17 + 2 19 38.43 31-27 + 19 48 34-85 + 41.68 - 0.15 +0.01 + 19 49 16.39 1-43 1476 1514 +37 17 + 2 15 38-43 33-04 + 19 46 35-74 + 2 39. 82 - 0. IS +0-05 + 19 49 15-46 0. 50 Dec. 17 675 745 +29 47 + 10 6 16-33 38-26 + 19 56 57-30 — 7 44-46 + 2.29 — 0. 12 + 19 49 15.01 0.05 675 755 +29 47 + 10 4 16-33 7.82 + 19 55 42.08 — 6 29.09 + 2.21 —0. 10 + 19 49 IS- 10 0. 14 808 867 + 21 29 + 17 49 6.76 28.91 + 19 39 17.84 + 9 54- 86 + 1-07 +0.15 + 19 49 13-92 1.04 904 929 +31 29 + 8 28 29.27 4-33 + 19 58 46.80 — 9 30.41 0. 00 -o.is + 19 49 16.24 1.28 986 B. A. C. 999 Mean (52 d + 19 18 +20 38 35-33 9.67 + 19 s8 22. 50 — 9 6.44 — 0. 69 — 0. 14 + 19 49 15-23 0. 27 + 19 49 14- 96 J-O. II Latitude of observing station. Port Plata, from zenith telescope observations by Lieut. Charles Laird. Corrections. Date. Number and catalogue. Apparent declination. Half sum of declina- tions. Latitude. Micrometer. Level. Ref. 1889. / // / // / // // // / // // Dec. 26 B. A. C. 1285 1322 + 5 +34 '4 18 5-43 2.80 + 19 46 4.12 + 2 42.23 0.00 +0.04 -fig 48 46.39 0. 24 1356 1367 + 17 +22 II 33 16.99 47- 87 + 19 52 32-43 — 3 53-81 + 4-73 — 0.06 + 19 48 43.29 2.86 1429 1445 — 3 +43 34 9 45-24 20.09 + 19 47 17.42 + I 23.30 + 6.08 +0. 02 + 19 48 46.82 0. 67 1476 1508 +37 + 2 17 19 39-55 30-32 + 19 48 34-94 + 9-36 + 1.22 0. 00 + 19 48 45-52 0.63 1476 1514 +37 + 2 17 15 39-55 32.08 + 19 46 35-82 + 2 9.08 + I. 22 +0.04 •f 19 48 46. 16 0. 01 1631 1657 +40 — 31 1.27 38.80 + 19 44 II. 24 + 4 24.05 + 11. IS +0.08 + 19 48 46-52 0-37 1631 1660 +40 — 29 1.27 33-96 + 19 45 13.66 + 3 21. 56 + 11. 15 -fo. 06 + 19 48 46.43 0.28 1 701 1742 + 15 +23 46 57 47-95 55-23 + 19 52 21.59 — 3 1.03 —32. 09 — 0.04 + 19 48 48.43 2.28 1766 1768 + 9 +30 13 25 47.24 34-74 + 19 49 40.99 — 46.68 - 6.76 — 0. 01 + 19 48 47.54 1-39 1880 B. A. C. 1939 + 19 +20 43 8 37-85 23-99 + ■9 56 0.92 — 7 10. 17 — 4.05 —0. 10 + 19 48 46.60 0-4S IN MEXICO, OEJSTEAL AMERICA, THE WEST INDIES, ETC. Latihide of observing station. Port Plata, from zenith telescope observations by Lieut. Charles /;»?'«/— Continued. 107 Date. Number and catalogue. Apparent declination. Half sum of declina- tions. Corrections, Latitude Micrometer. Level. Ref 1889. Dec. 27 B.A. C. 469 556 / + 17 53 +21 43 // 52.71 44.78 + 19 48 48.74 / — 12.83 + 10.47 // 0.00 + 19 / 48 46.38 1/ 0.23 580 61S +36 42 + 2 34 47-38 7-73 + 19 38 27.56 + IO 9-74 + 9-12 +0.17 + 19 48 46.59 0.44 625 649 + 2 13 +37 20 48.97 18.18 + 19 47 3-58 + I 48.06 — 7-09 fo.03 + 19 48 44.58 1-57 986 999 + 19 18 + 20 38 35-46 9.88 + 19 58 22. 67 — 9 22. 51 —15-54 — 0. 14 + 19 48 44.48 1.67 1040 1087 +27 12 + 12 33 47- >S 30-51 + 19 53 8.83 — 4 8.72 -12.83 — 0.06 + 19 48 47.22 1.07 1 132 1202 +33 36 + 6 12 44.28 9-99 + 19 54 27.14 — 5 35-70 — 6.08 — 0.09 + 19 48 45-27 0.88 1223 1272 +22 SI + 17 2 19. 12 41.36 + 19 57 u. 24 — 7 59-76 —13-51 —0. 12 + 19 48 46.8s 0. 70 1285 1322 + 5 14 +34 18 5-37 2. 90 + 19 46 4.14 + 2 47-71 — 8. II +0.0S + 19 48 43-79 2.36 1429 1445 — 3 34 +43 9 45-35 20. 24 + 19 47 17.44 + I 23-86 + 5-40 + 0.02 + 19 48 46.72 0-S7 1476 1508 +37 17 + 2 19 39-67 30.24 + 19 48 34-96 + 2.08 + 10.13 0.00 + 19 48 47.17 1.02 1476 B. A. C. 1514 Mean (21 de +37 17 + 2 IS terminations) . , 39- 67 32.00 + 19 46 35-84 + 2 0.34 + 10.13 +0.04 + 19 48 46-35 0. 20 + 19 48 46.15 -1-0. 19 Latitude of observing station, Santo Domingo City, from zenith telescope observations by Lieut. J. A. Norris. Corrections. Date. Number and catalogue. Apparent declination. Half sum of declina- tions. Latitude. Micrometer. Level. Ref. V. 1890. / // / ff / // // // / // // Jan. 7 B.A.C. 1332 1362 + 14 +22 49 49-66 2 28. go + 18 26 9.28 + I 58.42 0.99 +0.03 + 18 28 6-74 I. 64 1449 1500 +22 + 14 44 42. 10 3 57-69 +l8 24 19.90 + 3 39-90 + 4.20 +0.05 + .8 28 4-05 I. OS 155 1 1557 +21 +25 25 54-88 '4 58-77 + i8 20 26.83 + 7 34-67 + 2. 14 +0. II + 18 28 3-75 1-35 1571 1591 +21 +15 33 29.71 27 20. 30 + 18 30 25.00 — 2 21.84 + 1-30 — 0. 04 + 18 28 4.42 0.68 1611 1636 + 2 +33 43 42.49 SO 32.93 + 18 17 7.71 + 11 1.07 — 3-43 +0.17 + 18 28 5-52 0.42 1656 1681 + 8 +28 19 4. 78 30 49.84 + 18 24 57-31 + 3 12.06 - 3-05 +0.05 + 18 28 6.37 1.27 1 701 B.A.C. 1767 + IS +21 4# 47-60 4 27.98 + 18 25 37-79 + 2 29. 22 - 1-45 +0.04 + 18 28 5. 60 0.50 108 TELEGRAPBIC DETEEMINATION OF LONGITUDES Latitude of observing station, Santo Domingo City, from zenith telescope oinervations by Lieut. J. A. Norris —Continued. Date. Number and catalogue. Apirarent declination. Half sum of declina- tions. Corrections. Latitude. Micrometer. Level. Ref. v. 1890. / 1/ / // / ff // // / // // Jan. 7 B.A. C. 1767 iSio +21 + 16 4 2 27.98 13-71 + 18 23 20.85 - 5 13-17 - 1.83 —0.08 + 18 28 5-77 0.67 1767 1821 + 21 + 15 4 46 27.98 41. 10 + 18 25 34-54 + 2 32.04 - 1-83 +0.04 + 18 28 4-79 0.31 1837 1846 +24 + 12 31 36 47.10 55-86 + 18 34 21.48 — 6 20. 20 + 4-20 —0.09 + 18 28 S.38 0.28 1863 1928 + 27 + 9 35 38 7-77 46.03 + 18 36 56.90 — 8 52. II + 0.76 — 0. 14 + 18 28 S-4I 0.31 Jan. 8 1087 109s + 12 +24 33 5 30.03 41.19 + 18 19 35-61 + 8 29.58 — 0. 30 +0-13 + 18 28 5.02 0.08 "34 1 139 — 5 +42 34 13 6.64 53-97 + 18 19 53-67 + 8 IS- 18 — 2.06 +0. 14 + 18 28 6-93 1.83 1 162 1207 + 5 +31 42 33 12.78 24.40 + 18 37 48-59 — 9 39-50 — 2.75 —0.15 + 18 28 6. 19 1.09 1257 1302 +21 + 15 46 7 49-34 27.09 + 18 27 8.22 + 56.83 + 0.68 +0. 02 + 18 28 5-75 0.65 1257 1328 +21 +15 46 21 49-34 38- 98 + 18 34 14. 16 — 6 9. II + 1-37 —0.09 + 18 28 6.33 1.23 1260 1302 +21 +15 42 7 41-25 27.09 + 18 25 4.17 + 3 0.28 + 0.69 +0.04 + 18 28 5.18 0.08 1260 1328 +21 + 15 42 21 41-25 38-98 + 18 32 10. 12 — 4 5-66 + 1-37 —0.06 + 18 28 5-77 0. 67 1332 1362 + '4 +22 49 2 49. 66 28.94 + 18 26 9-30 + I 54-50 + 0.76 +0.03 + 18 28 4-59 0.51 1449 1500 +22 + 14 44 3 42- 15 57-69 + 18 24 19.92 + 3 44- 10 + 0. 15 +0. 06 + 18 28 4-23 0.87 1551 1557 +21 + 15 25 14 54-93 58-79 + 18 20 26.86 + 7 41-15 - 3-59 +0. II + 18 28 4-53 0-S7 1571 1591 +21 + 15 33 27 29.76 20.31 + 18 30 25-04 — 2 19.09 — 0.84 -0. 03 +18 28 5.08 0.02 1611 1636 + 2 +33 43 so 42.44 33-05 + 18 17 7-75 + 10 56-25 — 0.84 +0. 18 + 18 28 3-34 1.76 1656 1681 + 8 +28 19 30 4-75 49-93 + 18 24 57-34 + 3 6.42 + 0.38 +0.05 + 18 28 4.19 0.91 1701 1767 + 15 + 21 46 4 47.62 28.02 + 18 25 37-82 + 2 29. 22 - 1.76 +0.04 + 18 28 5-32 0.22 1767 1810 +21 + 16 4 2 28.02 13-73 + 18 33 20.88 - 5 17.58 + 0.46 —0.08 + 18 28 3.68 1.42 1767 1821 +21 + '5 4 46 28.02 41. 12 + 18 25 34.57 + 2 29.28 + 0-46 +0.04 + 18 28 4-35 0-7S 1837 1846 +24 + 12 31 36 47- 17 55-85 + 18 34 21.51 — 6 22.00 + 7-55 —0. 10 + 18 28 6.96 1.86 1863 B.A.C. 1928 +27 + 9 35 38 7-85 46. 00 + 18 36 56.93 - 8 49-63 — 0. 69 — 0. 14 + 18 28 6.47 1-37 IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. Latitude of observing station, Santo Domingo City, from zenith telescope observations by Lieut. J. .1. Mirris — Continued. 109 Date. Number and catalogue. Apparent declination. Half sum of declina- tions. Corrections. Latitude. ^- Micrometer. Level. Ref. n / // 1890. / // . / 1/ / n // // Jan. 9 B. A. C. 966 986 + 17 27 16. J3 + 19 18 35-27 + 18 22 55-80 + 5 10.00 — 0. 69 +0. oS fi8 28 5. 19 0. 09 994 looS — > 36 37- 41 +38 52 48.06 + 18 38 5-33 — 9 59-48 — 0.30 -0.17 + 18 28 5-38 0.28 1017 1041 +35 49 9- 35 + 3 16 37-88 + 18 32 53-62 — 4 50-37 0. 00 —0.08 + iS 28 3-17 1-93 1052 1087 + 24 20 2.04 + 12 ii 30.00 + 18 26 46.02 + I 18.88 + 0.08 +0. 02 + 18 28 5.00 0. 10 • 1087 1095 + 12 33 30.00 +24 5 4I.*20 + 18 19 35.60 + 8 27.72 + 0.46 +0. 13 + 18 28 3-9' I. 19 "34 "39 - 5 34 6.72 +42 13 54.07 + IS 19 53-68 + 8 10.57 + 0.84 +0.15 + 18 28 5-24 0. 14 1 162 1207 + 5 42 12.73 +31 33 24.46 + 18 37 48.60 — 9 44-32 + 1.60 -0.15 + 18 28 5.73 0.63 I2S7 1302 +21 46 49.36 + 15 7 27.09 + i8 27 8.23 + 58-76 - 1.83 +0. 01 + 18 28 5-17 0.07 1257 1328 +21 46 49.36 + 15 21 38.98 + 18 34 14.17 — 6 5.88 - 1.68 —0.09 + 18 28 6.52 1.42 1260 1302 + 21 42 41.27 + 15 7 27.09 + 18 25 4. 18 + 3 2.76 - 1.83 +0.05 + 18 28 5-16 0. 06 1260 1328 +21 42 41.27 + 15 21 38-98 + 18 32 10.13 — 4 1.87 — 1.68 —0. 06 + 18 28 6.52 1.42 1449 ISCX3 +22 44 42. 18 + 14 3 57-69 + 18 24 19.94 + 3 43-48 + 0.30 +0. 06 + 18 28 3-78 1.32 iSSi IS57 +21 25 54.96 + '5 14 58 79 + 18 20 26.87 + 7 29.44 + 8.24 +0. II + 18 28 4.66 0.44 1571 1591 + 21 33 29. So + 15 27 20.32 + 18 30 25.06 — 2 20.40 + 0.08 — 0.03 + 18 28 4.71 0.39 1611 1636 + 2 43 42. 38 +33 50 33.15 + 18 17 7-77 + 10 53.35 + 1.98 +0. 18 + 18 28 3-28 1.82 1656 B.A.C. 1681 Mean (45 de + 8 19 4.72 +28 30 50. 01 terminations) ...... + 18 24 57.37 + 3 6.55 + 0.23 +0.05 + 18 28 4. 20 0. 90 + 18 28 5.10 -j-o. 10 no TELEGRAPHIC DETERMINATION OF LONGITUDES Latitude of obscrviiv^ station, Curacao, from zenith telescope observations by Lieut. Charles Laird. Date. iSgo. Jan. 26 Jan. 27 Jan. 2S Number and caLalugue. B. A. C. 1304 1366 1485 1491 1722 1734 1759 1772 1304 1366 1434 1442 1500 1516 1551 1611 1571 lOII 1986 2059 2126 2163 1500 1516 1908 1925 1908 B. A. C. 1970 Mean (14 determinations) ^^parent declination. Half sum of declina- tions. / // / 1/ + 8 + 15 36 41 54.42 18. II + «2 9 •6.26 + 15 + 8 42 42 40. 27 34.58 + 12 12 37-42 + 5 + 18 51 27 45-76 38.92 + 12 9 42-34 — 4 +29 54 9 46.81 11.48 + 12 7 12.34 + 8 +>5 36 41 54.34 18.05 + 12 9 6. 20 + 12 + 11 17 58 19.34 49.16 + 12 8 4.25 +14 + 9 3 58 57.19 26. II + 12 I H.65 +21 + 2 25 43 55.07 40. 98 + 12 4 48.02 +21 + 2 43 29.93 40. 98 + 12 8 35-46 + ■9 + 4 48 38 49.86 48. 88 + 12 ■3 49-37 + 7 + 16 24 29 43.72 31-19 + " 57 7-46 + 14 + 9 3 58 57.13 26.04 + 12 I 11.59 + I +22 49 23 26. 23 48-35 + 12 6 37-29 + I + 22 49 12 26.23 29.79 + 12 58-01 Corrections. Micrometer. Level. f // // — 2 49. 66 + 2.92 - 6 3-31 —12.65 —3 20. 66 0. 00 — 38.70 -12.37 — 2 58.95 + 15.00 — I 28.02 -'2-37 + 5 8.72 0.00 + I 40.85 - 6. 13 — 2 6.37 -6.13 - 7 21. 12 -7-38 + 9 16.54 — 0. 40 + 5 5.12 + 2.29 — 19.07 + 4-81 + 5 21.41 + 4-81 Ref. -o. 04 -o. 09 — 0.05 -o. 04 +0.08 +0.03 -0.03 +0. 14 +0.07 Latitude. o / // + 12 6 19. + 12 6 21.37 + 12 6 21.03 + 12 6 21.26 + 12 6 22.21 + 12 6 23.84 + 12 6 20.45 + 12 6 22. 77 + 12 6 22.93 + 12 6 20.76 + 12 6 23.74 + 12 6 19.07 + 12 6 23.02 + 12 6 24.31 2-44 0-55 o. 29 0.66 o. 29 .92 1.47 0.65 1. 16 1.82 2.85 2.39 + 12 6 21.92 +0.29 m MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. Latiiude of observing station La Guayra,from wiiilh telescope obsei-vations by Lieut. Cliarles Laird. Ill Corrections. Date Number and catalogue. Apparent declination. Half sum of declina- tions. Latitude. Micrometer. Level. Ref. 1890. Feb. 8 B.A. C. 1908 1934 / + I 49 + 19 41 // 25.60 29. II + 10 / 45 1/ 27.36 / — 8 34-65 II + 0-29 II —0.13 ■ +10 / // 36 52-87 II 0.82 2123 2140 + 4 55 + 16 17 57-49 25.04 + 10 36 41.27 ■\ 8.05 + 3-95 0.00 + 10 26 53.27 0.42 2123 2163 + 4 55 + 16 29 57-49 31-22 + 10 42 44-36 — 5 55- «9 + 3-95 -0.08 + 10 36 53- 04 0.65 2123 2184 + 4 55 -)-i6 29 57-49 56.24 + 10 42 56.86 — 6 6. 91 ■A- 3- 95 — 0.09 + 10 36 53-81 0. 12 2123 2228 + 4 55 + 16 19 57-49 37-64 + 10 37 47-56 — 57.29 + 3- 95 -0. 01 + 10 36 54.21 0. 52 Feb. 1 1 1944 1989 + 5 25 + 16 9 26.25 14.99 + 10 47 20.62 — 10 29.23 — 0.57 —0. 16 + 10 36 50. 66 3-03 1944 2005 + 5 25 + 16 4 26. 25 0.75 + 10 44 43-50 - 7 S'-79 — 0.57 — 0. 12 + 10 36 51.02 2. 67 1944 2009 + 5 25 -|-i6 10 26. 25 32.68 + 10 47 59.46 — II 4.68 — 0.57 —0. 17 + 10 36 54- 04 0-35 Feb. 12 '370 i486 + 14 27 + 6 46 48.94 0. 62 + 10 36 54-78 + 2- IS — 2. 29 0.00 + 10 36 54- 64 0.95 1409 i486 + 14 36 + 6 46 40.83 0. 62 + 10 41 20. 72 - 4 23.64 — 2.29 — 0. 06 + 10 36 54-73 I. 04 1493 1514 + 18 39 + 2 IS 5.18 28.53 + 10 27 16.86 + 9 38.88 - 3-95 +0.15 + 10 36 51-94 1-75 1647 1685 + 19 27 + I 44 52.23 33-84 + 10 36 13.04 + 42-38 — 1. 14 +0.01 + 10 36 54. 29 0.60 1651 1685 + 19 42 + I 44 8-31 33- 84 + 10 43 21.08 — 6 23.08 — I. 14 — 0. 10 + 10 36 56-76 3-07 1834 B. A. C. 1883 Mean (14 d« + •3 51 + 7 23 29.88 4.56 + 10 37 17. 22 — 19.84 — 0.97 — 0. 01 + 10 36 56- 40 2.71 10 36 53-69 +0.32 I I RESULTS. 21124— No, 97 8 114 TELEGRAPHIC DETBKMmATiON OF LONGITUDES RESULTS. The results of the foregoing observations are given as follows : The first two tables show the final clock corrections deduced from the observations made by Lieut. J. A. Norris and Lieut. Charles Laird. The third table shows the difference of the chronometer faces on each night as deduced from the exchange of time signals. The fourth table gives the difi'erences of longitude between the various stations on each night on which time signals were exchanged and observations made. The data for this table are taken from the preceding tables of clock corrections and chronometer comparisons. The last column in this table shows the wave and armature time, a? — J (A' — A"). In the measurements between Vera Cruz and Coatzacoalcos, and Coatzacoalcos and Salina Cruz, which were made automatically, this quantity may be regarded as the true wave and armature time. In the other measurements the comparisons were made by the use of the mirror galvanometer, and the personal equation of the observers in noting the mirror signals is involved in the quantity co. Finally the resulting latitudes and longitudes of the various stations, reduced to the adopted land- marks at each station, are given. Final chronometer corrections from observations by Lieut. J. A. Norris, U. S. Navy. Place. Date. Chro- nometer. Epoch of reduction. AT at epoch of reduction. Hourly rate. Epoch of comparison. /\T at epoch of comparison. Coatzacoalcos 1888. Dec. 29 129s h. m. 3 44-0 h. m. s. — 48 36. 089 J. +0.071 k. m. 7 25.8 k. m. s. —0 48 3S. 826 Dec. 30 1295 5 "-3 —0 48 34. 283 +0. 069 5 25.1 —0 48 34.267 1889. Jan. 7 1295 4 27.8 — 48 21.892 -f-o. 062 Jan. 12 1295 3 3-8 — 48 14. 650 -)-o. 061 8 27.8 — 48 14.321 Jan. 14 129s 3 21.2 — 48 II. 422 +0. 080 Jan. IS 129s 3 22.5 — 48 9.316 +0. 094 7 52.3 —0 48 8. 893 Jan. 16 1295 3 7-9 —0 48 7. 058 -|-o. 091 7 55.7 —0 48 6.621 Jan. 17 129s 3 i8-5 — 48 5.087 +0. 072 8 24.6 —0 48 4. 720 Salina Cruz Feb. 9 129s 9 48.8 —0 53 58.103 +0. 188 Feb. 10 129s 6 58.8 -0 53 54.265 +0. 178 5 45-8 —0 S3 54.482 Feb. II 129s 6 42.7 — 53 50. 122 +0. 169 Feb. 12 1295 6 30. 6 —0 53 46. 241 +0. 159 II 31.8 —0 53 45-443 •Feb. 13 1295 6 28.4 —0 S3 42.494 +0. 157 9 24.^ —0 53 42.034 Feb. 14 1295 6 30-5 —0 53 38.596 +0. i6g 9 39-3 -0 53 38.064 Feb. 15 1295 6 53-3 —0 53 34.368 +0. 173 9 39-8 —0 53 33-830 Feb. 16 1295 6 42.9 -0 53 30.316 +0. 165 9 46.2 ■-0 S3 29.811 IN MEXICO, OENTKAL AMERICA, THE WEST INDIES, ETC. 115 Final chronometer corrections from observations by Lieut. J. A. Norris, U. S. Navy — Continued. Place. Date. Chro- nometer. Epoch of reduction. AT at epoch of reduction. [lourly rate. Epoch of comparison. AT at epoch of comparison. Lq. I_.ili)£rta.(l 1889. Mar. 9 Mar. 12 129s 1295 h. 8 m. 43-1 h. — m. 28 s. 35- 489 21. 426 s. +0. 210 -fo. 189 h. m . h. m. J. J-JkL Jk.dAI^X^X LKft\.A «■••■• 7 —0 28 12 23.3 - -0 28 20. 456 Mar. 13 1295 8 22.0 —0 28 16. 626 -|-o. 201 II 36. 8 — 28 15-973 Mar. 14 129s 7 24. — 28 11.859 +0. 205 II 36.4 -0 28 10. 996 Mar. 16 1295 7 22. 2 — 28 3.006 +0. 174 12 34-3 — 28 2. lOI Mar. 17 1295 7 17.9 — 27 58. 907 +0. 168 8 25.2 — 27 58.719 Mar. 18 1295 7 16.3 — 27 54- 976 -fo. 160 12 50.9 —0 27 54. 083 San Juan del Sur .... Mar. 30 1295 14 25-9 —0 13 16.336 +0. 165 12 39.6 — 13 16.628 Mar. 31 1295 9 17.7 — >3 13-153 -fo. 170 10 29.4 — 13 12.949 Apr. I 1295 8 56.9 — 13 9-094 +0. 174 12 21.7 — 13 8. 327 Apr. 2 1295 8 35-8 — 13 4.976 +0. 180 13 43-8 — 13 4-053 St. Nicolas Mole .... Nov. 27 1295 22 34-2 +0 14 S3- 84s +0. 043 . . . Nov. 28 «295 I 43-2 +0 14 55- 365 +0. 067 31.8 +0 14 55-285 Nov. 29 129s 22 44.1 +0 14 56. 868 -f 0. 070 22. 6 +0 14 56.983 Nov. 30 •295 22 53-6 +0 14 58. 420 -f 0. 060 20. I +0 14 58.507 Dec. I 129s 22 Si-9 +0 14 59.770 +0. 052 43-6 +° 14 59.867 Dec. 2 1295 23 II. I +0 15 0-9S3 -f 0. 047 2 39.7 +0 15 I. 116 Dec. 3 129s 23 26.8 +0 IS 2. 100 +0. 046 52.7 +0 15 2. 166 Dec. 4 129s 23 19.7 +- IS 3-172 -f 0.044 . . . • . . . Dec. 13 1295 23 27.6 +0 15 II. 522 +0. 074 . . . . . . Dec. 14 129s 23 26. 5 +0 IS 13- 30s +0. 074 I 13.2 +0 15 13-437 Dec. 15 1295 23 51-3 +0 IS 15-032 -f 0. 062 I 56.2 +5 15 15. 161 Dec. 16 1295 49.0 +0 IS i6. 505 +0. 075 I 23.9 +0 15 16. 549 Dec. 17 1295 17.8 +0 15 18. 611 +0. 086 . . . Dec. 18 129s 23 57.2 +0 IS 20. 314 +0. 067 . Dec. 19 1295 20.8 +0 IS 21.887 +0. 066 2 5.0 +0 15 22. 002 Dec. 20 129s I 15.0 +0 15 23.588 +0. 072 2 22. 2 +0 15 23-669 Santo Domingo . . 1890. Jan. I 129s 3 21.6 +0 29 40. 577 +0. 032 . . . , . • * Jan. 2 1295 4 12.6 +0 29 41.604 +u. 049 3 2. +0 29 41-S46 Jan. 3 1295 3 38.5 +0 29 42. 829 +0. 046 3 8.8 +0 29 42. 806 Jan. 4 1295 3 39-4 +° 29 43. 806 -f 0. 050 3 i-o +0 29 43-774 Jan. 5 1295 I 52. 2 +0 29 45-^256 -f 0. 064 2 57.8 +0 29 45-326 Jan. 6 1295 4 37-8 +0 29 46. 845 +0. 065 3 23.9 +0 29 46.765 Jan. 7 1295 3 2.7 +0 29 48. 601 -f 0. 089 . . . . Jan. 18 1295 4 18.7 +0 30 4-333 +0. 061 . . . Jan. 20 129s 5 43-4 +0 30 7.418 -f 0. 064 4 49-6 +0 30 7. 361 Jan. 21 1295 4 36.0 +0 30 8.884 +0. 064 4 40.2 +0 30 8. 888 Jan. 22 1295 4 34-6 +0 30 10. 398 -f 0. 060 5 4-4 +0 30 lo. 428 Jan. 23 1295 4 46.8 +0 30 11.798 -f 0. 058 5 10.9 +0 30 11. 821 Jan. 24 •295 4 44-3 +0 30 13- 239 -f 0. 060 5 28.8 +0 30 13.284 Jan. 25 1295 4 IS- 3 +0 30 14. 640 +0. 059 5 28.7 +0 30 14.712 Feb. 5 1295 s 15-2 +0 30 26. 474 +0. 042 . . . . . . Feb. 7 129s 5 40.9 +0 30 28. 858 +0. 057 6 30.4 +0 30 28. 905 Feb. 8 1295 5 32.9 +0 30 30. 327 ■f 0. 050 6 35- +0 30 30-379 Feb. 9 1295 S 17.8 +0 30 31.277 -f 0. 050 . . . . . . Feb. 10 129s 6 47-4 +0 30 32- 743 +0. 055 6 40.2 +0 30 32.736 Feb. II 1 29s 9 36.3 +0 30 34- 033 +0. 047 6 38.5 +0 30 33-894 Feb. 13 1295 7 9.0 +0 30 36.517 +0. 059 ■ • - 116 TELEGRAPHIC DETERMINATION OF LONGITUDES Final chronometer corrections from observations by Lieut. Charles Laird, U. S. Navy. Place. Date. iSSS. Dec. 26 Chro- nometer. Epoch of reduction. /\T at epoch of reduction. Hourly rate. Epoch of comparison. /\T at epoch of comparison. Vera Cruz ... 1254 h. 4 VI. 24-3 -t m. '3 s. 23. 270 s. •+-0. 043 h. m. h. »/. s. Dec. 27 1254 4 44.6 — I 13 22.155 +0. 041 7 10. — I 13 22.053 Dec. 29 1254 4 7-4 — I 13 20. 279 +0. 047 7 38.0 —I 13 20. 115 Dec. 30 1254 3 38.1 — I 13 19. 118 +0- 053 5 31.0 -I 13 19.018 1889. Jan. 1 2 1254 4 46.9 I 13 5-952 +0.051 8 43-0 — I 13 5-752 Jan. 15 1254 3 38.4 — I 13 2. 296 -|- 0. 046 8 9.0 — I 13 2.088 Jan. 16 1254 4 0.6 — I >3 1. 189 +0. 049 8 8.0 -I 13 0.987 Jan. 17 I 254 4 4-9 — I 12 59-877 +0.057 8 37-0 — I 12 59.618 Coatzaooalcos Feb. 10 •254 8 2,9 — 1 5 32. 281 +0. 074 5 50.0 —I 5 32. 445 Feb. 12 1254 8 18.6 — I 5 30-315 -fo. 021 II 40. — i 5 30- 246 Feb. 13 1254 6 37-2 —I 5 29-773 +u. 069 9 39.1 —1 5 29.524 Feb. 14 1254 6 4-9 — I 5 28. 040 +0. 067 9 50.0 -I 5 27. 789 Feb. 15 1254 6 20. 9 5 26. 761 +0.052 9 47.0 -I 5 26.583 Feb. 16 1254 5 52.6 — 1 5 25. 370 4-0. 062 9 57.0 — I 5 25.118 Salina Cruz Mar. 12 1254 10 IS- 3 —I 8 45- 783 +0. 141 12 40. 2 — I 8 45. 443 Mar. 13 1254 9 25.0 —I 8 42.481 -|-o. 146 II 52.8 — I 8 42. 121 Mar. 14 1254 9 21.4 -I 8 38- 924 +0. 151 II 53-4 — I 8 38- 542 Mar. 16 1254 12 38-9 —I 8 30. 468 +0. 168 12 51.8 —I 8 30- 432 Mar. 17 1254 10 55.0 —I 8 26.871 -|-o 160 8 42.2 — I 8 27. 224 Mar. 18 1254 9 6.9 ■-I 8 23-372 +0- 158 13 7.9 -I 8 22.737 Mar. 30 1254 II 18.6 —I 7 49. 898 -)-o. 160 12 56.9 — I 7 49. 636 Mar. 31 1254 12 39-5 — I 7 46. 172 +0. 143 10 47.1 — I 7 46- 439 Apr. I 1254 10 26. 3 —I 7 43- 036 +0. 140 12 39.0 —I 7 42.727 Apr. 2 1254 10 40. I — I 7 39 625 -}-o. 140 14 I. I -1 7 2,9- 'S6 Santiago de Cuba . . ISov. 28 1254 3 15.1 +0 5 39- 583 -|-o. 120 31.2 +0 5 39- 255 Nov. 29 1254 2 7.2 +0 5 42.357 4-0.119 21.9 +0 5 42, 148 Nov. 30 1254 2 I. I +0 5 45-163 +0. 121 19.5 +0 5 44- 959 Dec. I 1254 2 10. 9 +0 5 48.177 +0. 124 43.0 +0 5 47- 995 Dec. z 1254 2 27.8 +0 5 51.145 +0. 118 2 39-0 +0 5 51.167 Dec. 3 1254 I 23-3 +0 5 53. 692 -|-o. no 52.0 +0 5 53- 635 Port Plata Dec. 14 1254 3 38.8 +0 26 54- 623 +0. 094 I 12.3 +0 26 54- 394 Dec. 15 1254 23 58.9 +0 26 56.516 +0. 089 I 55-3 +0 26 56. 689 Dec. 16 1254 3-4 +0 26 58. 572 +0. 087 I 23. +0 26 58. 687 Dec. 19 1254 22. 6 +0 27 4-935 +0. 086 2 4.0 + 27 5.080 Dec. 20 1254 2 37-9 +0 27 7-144 +0. 085 2 21.3 +0 27 7. 120 Dec. 28 1254 1254 2 2-5 33-2 +0 +0 27 27 24- 927 35-529 +0. 088 -]-o. 070 1890. Jan. 2 3 0.9 +° 27 35-631 Jan. 3 1254 29.1 +0 27 37-173 +0. 073 3 7.6 +0 27 37- 293 Jan. 4 1254 2.8 +0 27 39- 057 +0. 086 2 59.8 +0 27 39- 225 Jan. 5 1254 34-4 +0 27 41-237 -fo. 089 2 56.6 +0 27 41-359 Jan. 6 1254 46.6 +0 27 43- 381 +0. 089 3 22. 2 +0 27 43-523 Crua(;ao Jan. 20 1254 4 32-3 +0 35 27. 879 +0- 123 4 48.0 +0 35 27.911 Jan. 21 1254 2 22. I +0 35 30- 437 +0. 109 4 38.6 +0 35 30. 685 Jan. 22 1254 6 13- I +0 35 33- 263 -j-O. 102 5 2-7 +0 55 33- 143 Jan. 23 1254 3 26. 3 +0 35 35- 505 +0. no 5 9-3 +0 35 35- 694 Jan. 24 1254 3 19.4 +0 35 38. 250 -|-o. 116 5 27. 2 +0 35 38. 497 Jan. 25 1254 3 23-7 +° 35 41.023 +0. 114 5 27. +0 35 41-257 La Guayra Feb. 7 1254 4 10. 9 +0 44 12.576 +0.053 6 28.4 +0 44 12.697 Feb. 8 1254 4 14.5 +0 44 13. 842 +0- 055 +0 44 13-971 Feb. 9 1254 S 19- 3 +0 44 15. 266 +0. 055 • • Feb. 10 1254 4 24.5 +- 44 16.553 -f-o. 061 6 38 3 +0 44 16. 689 Feb. II 1254 4 30.1 +0 44 18. 149 +0. 068 6 36-5 +0 44 18. 292 IN MEXICO, CENTRAL AMERICA, THE WEST INDIES, ETC. 117 Differences of chronometer faces from mean of time signals. Dale. Signa s sent. Mean difference and probable error. Eastern — Western chronometers. From — To— i888. Dec. 29 Coatzacoalcos . . . Vera Cruz 22 h. —0 m. 17 s. 49-555 s. -|-o. 000 Vera Cruz Coatzacoalcos 25 —0 17 49. 478 J-o. 002 Dec. 30 Coatzacoalcos Vera Cruz 25 —0 17 50. 092 -J-o. 000 1889. Jan. 12 Vera Cruz Coatzacoalcos Coatzacoalcos Vera Cruz 8 25 —0 17 17 50. 001 5^- 744 -I-O. 002 -I-O. OOI Vera Cruz Coatzacoalcos 25 — 17 56. 620 J-O. OOI Jan. IS Coatzacoalcos Vera Cruz 25 — 17 58. 720 -l-O. OOI Vera Cruz Coatzacoalcos 25 — 17 58. 607 -I-O. OOI Jan. 16 Coatzacoalcos Vera Cruz 25 — 17 59.670 -|-0. OOI Vera Cruz Coatzacoalcos 25 — 17 59-55° -I-O. 000 Jan. 17 Coatzacoalcos Vera Cruz 25 —0 18 0.438 -I-O. OOI Vera Cruz Coatzacoalcos 25 — 18 0.313 -J-O. OOI Feb. 10 Salina Cruz Coatzacoalcos . . IS +0 14 43- 227 -}-0. OOI Coatzacoalcos Salina Cruz 25 +0 14 43- 136 -J-O. OOI Feb. 12 Salina Cruz Coatzacoalcos IS +0 14 49.817 J-O. 002 Coatzacoalcos Salina Cruz 25 +0 14 49- 770 -I-O. OOI Feb. 13 Salina Cruz Coatzacoalcos 25 +0 14 52. 500 J-O. OOI Coatzacoalcos Salina Cruz 25 +0 14 52-427 J-O. OOI Feb. 14 Salina Cruz Coatzacoalcos 25 +0 14 55. 296 -J-O. OOI Coatzacoalcos Salina Cruz 25 +0 14 55- 247 -J-O. OOI Feb. IS Salina Cruz Coatzacoalcos 25 +0 14 57-933 -J-O. OOI Coatzacoalcos . . Salina Cruz • 25 +0 14 57. 899 J-O. 000 Feb. 16 Salina Cruz Coatzacoalcos 25 +0 15 0-515 J-O. OOI Coatzacoalcos Salina Cruz 25 +0 15 0,452 J-O. OOI Mar. 12 La Libertad Salina Cruz 70 —0 16 57-967 J-O. 003 Salina Cruz La Libertad 68 — i6 57-316 J-O. 004 Mar. 13 La Libertad Salina Cruz 67 -0 16 59-155 J-O. 003 Salina Cruz La Libertad 67 — 16 58.561 J-O. 004 Mar. 14 La Libertad Salina Cruz 74 — 17 0.485 JrO. 003 Salina Cruz La Libertad 62 — 16 59.891 ±0- 003 Mar. 16 La Libertad Salina Cruz 64 — 17 1-325 J-O. 003 Salina Cruz . ... La Libertad 67 — 17 0.756 J;0. 002 118 TELEGKAfaiG l)EtEUMliJAWON OF LONGITUDES Differences of chroHotiuter faces from mean of time signals — Continued. Date. Mar. 17 Mar. 18 Mar. 30 Mar. 31 Apr. I Apr. 2 Signals sent. From- La Libertad Salina Cruz La Libertad Salina Cruz San Juan del Sur Salina Cruz . . San Juan del Sur . Salina Cruz . . San Juan del Sur . Salina Cruz . . . San Juan del Sur Salina Cruz . . Nov. 28 Nov. 29 Nov. 30 Dec. I Dec. 2 Dec. 3 Dec. 14 Dec. IS Dec. 16 Dec. 19 St. Nicolas Mole Santiago de Cuba . St. Nicolas Mole . Santiago de Cuba . St. Nicolas Mole . Santiago de Cuba . St. Nicolas Mole . Santiago de Cuba , St. Nicolas Mole . Santiago de Cuba . St. Nicolas Mole . Santiago de Cuba . St. Nicolas Mole . Port Plata .... St. Nicolas Mole Port Plata . . . St. Nicolas Mole Port Plata . . . St. Nicolas Mole . Port Plata To— Salina Cruz . . La Libertad . . Salina Cruz . . La Libertad . . Salina Cruz . . San Juan del Sur Salina Cruz . . San Juan del Sur Salina Cruz . San Juan del Sur Salina Cruz . . San Juan del Sur Santiago de Cuba St. Nicolas Mole Santiago de Cuba St. Nicolas Mole Santiago de Cuba St. Nicolas Mole Santiago de Cuba St. Nicolas Mole Santiago de Cuba St. Nicolas Mole Santiago de Cuba St. Nicolas Mole Port Plata . . . St. Nicolas Mole Port Plata . . . St. Nicolas Mole Port Plata . . . St. Nicolas Mole Port Plata . . . St. Nicolas Mole 71 66 64 73 73 73 72 73 69 73 64 68 71 72 69 71 66 72 62 66 72 72 70 72 73 72 72 66 74 73 71 68 Mean difference and probable error. Eastern — Western chronometers. h. — o — o — o — o — o — o — o — o — o — o — o +0 4-0 +0 +0 +0 +0 +0 +0 +0 +-^ 4-0 — o — o — o — o — o — o — o — o m. 17 17 17 17 17 17 17 17 17 17 17 17 o o o o o o o o o o o o o o o o o o o o I- 552 0. go6 1. 6og 1.003 19- 593 18.875 19.946 19-237 20. 567 19.865 21. 630 20. 905 34- 050 34-510 35- 202 35-666 36. 545 37.021 38. 160 38. 660 40- 055 40. 529 41-475 41.961 54.672 55- "5 55-122 55.612 55-833 56. 323 56. 650 57. 125 -J_o. 004 j-o. 003 j-o. 004 -j-o. 002 ±0. 003 -1-0. 003 -1-0. 003 j-o. 003 -1-0. 003 _j-o. 003 -1-0. 003 ±0- 003 -(-o. 004 -J-O. 002 -j-o. 003 ±0. 003 -|-o. 004 -j-o. 002 -|-o. 002 J;0. 002 -J-o. 003 -J-O. 002 -J-O. 002 -j-o. 003 J-o. 004 -J-o. 003 -J-o. 003 -J-o. 004 -J-O. 002 ±0. 003 -l-o. 002 J;0. 002 IN MEXICO, CBJSTEAL AMERICA, THE WEST INDIEiS, ETC. 119 Differences of chronometer faces from mean of time signals — Continued. Date. Dec. 20 1890. Jan. 2 Jan. 3 Jan. 4 Jan. 5 Jan. 6 Jan. 20 Jan. 21 Jan. 22 Jan. 23 Jan. 24 Jan. 25 Feb. 7 Feb. 8 Feb. 10 Feb. II Signals sent. From — St. Nicolas Mole Port Plata . . . Santo Domingo . Port Plata . Santo Domingo . Port Plata . . . Santo Domingo . Port Plata . . . Santo Domingo . Port Plata . . . Santo Domingo . Port Plata . . Santo Domingo . Curasao . . . . Santo Domingo . Curasao . . . . Santo Domingo . Curasao . . Santo Domingo . Curasao . . . . Santo Domingo . Curasao . . . . Santo Domingo . Curasao .... Santo Domingo . La Guayra . . . Santo Domingo . La Guayra . . . Santo Domingo . La Guayra . . . Santo Domingo . La Guayra . . . To- Port Plata . . St. Nicolas Mole Port Plata . . . Santo Domingo . Port Plata . . . Santo Domingo . Port Plata . . . Santo Domingo . Port Plata . . . Santo Domingo . Port Plata . . . Santo Domingo . Curasao . . . . Santo Domingo . Curasao . . . . Santo Domingo . Curagao .... Santo Domingo . Curasao .... Santo Domingo . Curagao . . . . Santo Domingo . Curagoa .... Santo Domingo . La Guayra . . . Santo Domingo . La Guayra . . . Santo Domingo . La Guayra . . . Santo Domingo . La Guayra . . . Santo Domingo . 12; 70 68 67 70 67 73 70 73 67 68 72 69 71 71 70 69 69 72 69 73 72 67 69 73 66 67 69 64 73 73 67 69 Mean difference and probable error. Eastern — Western chronometers. h. — o +° +0 +0 +0 +0 +0 +0 +0 +0 +0 — o — o — o — o — o — o — o — o — o — o — o — o — o — o — o — o — o — o — o — o m. o s. 57. 068 57-541 8. 189 8.654 8.617 9. 106 9.421 9.823 10. 354 10. 750 10. 846 11. 320 34- 150 34- 781 35- 335 35. 906 36. 291 36. 866 37- 420 37-991 38. 740 39- 344 40. 099 40. 664 55.782 56. 448 55-754 56-425 56. 042 56. 694 56. 403 57.079 s. ±0-003 J-o. 003 ±0.003 ±0.003 ±0. 003 ±0. 003 -|-o. 002 ±0.003 ±0. 003 ±0.004 ±0. 003 ±0.003 J^o. 002 ±0. 003 ±0.003 ±0. 004 ±0. 003 J;0. 004 ±0.003 ±0.003 ±0. 003 ±0. 004 ±0. 003 J;0. 002 ±0.003 ±0. 003 ±0. 002 ±0. 003 -J-o. 002 ±o. 003 ±0. 003 ±0. 003 120 TELEGRAPHIC DBTEEMINATION OF LONGITUDES Differences of longitude deduced from exchange of time signals. Eastern and Western Stations. I.a Libertad . Salina Cruz . La Libertad . Salina Cruz . La Libertad . Salina Cruz . La Libertad . Salina Cruz r,a Libertad . Salina Cruz . Date. Coatzacoalcos Vera Cruz . . Coatzacoalcos Vera Cruz . . Coatzacoalcos Vera Cruz . . Coatzacoalcos Vera Cruz . . Coatzacoalcos Vera Cruz . . Coatzacoalcos Vera Cruz . . Coatzacoalcos Salina Cruz . Coatzacoalcos Salina Cruz . Coatzacoalcos Salina Cruz . Coatzacoalcos Salina Cruz . Coatzacoalcos Salina Cruz . Coatzacoalcos Salina Cruz . La Libertad . Salina Cruz Dec. 29 \ 30 1 Dec. 188 Jan. Jan. Jan. Jan. IS i6< 17- Feb. 10- Feb. 12- Feb. 13 1 Feb. 14/ Feb. 15 I Feb. 16/ Mar. 1 2-! Mar. 13 1 Mar. 14 ■[ Mar. 1 6-! Mar. I7< Mar. 18 N. L. N. L, N. L. N. L. N. L. N. L. L. N. L. N. L. N. L. E. N. W. L. E. N. W. E. W. E. W. E. W. E. W. E. W. E. W. o w ^T^ and l\Tw h. VI. -o 48 -« 13 -o 48 -I 13 -o 48 -I 13 -o 48 -I 13 ~o 48 -I '3 35.826 20. 115 34.267 19. 018 14.321 S-7S2 8.893 2.088 6. 621 0.987 4.720 59.618 -I 5 32-445 -o 53 54.482 ATc— ATro -I s 30. 246 -0 S3 45- 443 -I S 29. 524 — S3 42. 034 -I S 27. 789 -0 S3 38. 064 -I S 26. 583 -0 53 33-830 -I 5 25. u8 — S3 29.811 — 28 20. 456 —I 8 45- 443 — 28 15-973 —I 8 42. 121 — 28 10. 996 — I 8 38. 542 — 28 2. lOI —I 8 30- 432 — 27 58-719 —I 8 27. 224 — 27 54- 083 -I 8 22.737 in. s. +24 44. 289 +24 44-751 +24 51-431 +24 S3- 195 +24 54-366 +24 54. 898 —II 37-963 —II 44-803 — II 47-490 —II 49-725 — II 52-753 —II 55-307 +40 24. 987 -I-40 26. 148 +40 27. 546 +40 28.331 +40 28. 505 +40 28.554 O w ■2 '- 3 4J 22 25 25 8 25 25 25 25 25 25 25 25 IS 25 IS 25 25 25 25 25 25 25 25 25 70 68 67 67 74 62 64 67 71 66 64 73 T' and 1" 7 49-555 7 49- 478 7 50. 092 7 50. 001 7 56.744 7 55. 620 7 58-720 7 58. 607 7 59-670 7 59- 550 8 0.438 8 0.313 4 43- 227 4 43- 136 4 49-817 4 49- 770 4 52-500 4 52.427 4 55-296 4 55- 247 4 57-933 4 57- 899 0.515 0.452 6 57. 967 6 57.316 6 59. 155 6 58. 561 7 0.485 6 59-891 1-325 0-756 I- 552 0. 906 1. 609 1.003 V and V A- 6 54 + 6 54 + 6 54. + 6 54 + 6 54 + 6 54. + 6 54 + 6 54 + 6 54. + 654. + 6 54 + 6 54. + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 + 3 734 811 659 750 687 811 475 588 696 816 460 58s 264 173 014 967 010 937 571 522 180 146 208 145 -(-23 27. 020 +23 27.671 +23 26. 993 +23 27. 587 +23 27.061 +23 27.655 +23 27.006 +23 27. 575 +23 26. 953 +23 27. 599 +23*27.045 +23 27.651 \{V-V') m. s. + 6 54. 772 + 6 54. 704 + 6 54. 749 + 6 54. 532 + 6 54. 756 + 6 54.522 + 6 54-672 + 3 5.218 + 3 4-990 + 3 4-974 + 3 5- 546 + 3 5- 163 + 3 5-176 + 3 5- 178 +23 27.346 +23 27.290 +23 27. 358 +23 27.290 +23 27.276 +23 27. 348 +23 27.318 0.038 0.046 0.062 0.056 0.060 0.062 0.046 0.024 0.036 0.024 o. 017 0.032 o. 326 o. 297 o. 297 o. 284 0.323 0.303 IN MEXICO, CENTK-IL AMEEICA, THE WEST INDIES, ETC, VJl Differences of longitude deduced from exchange of time signals — Continued. Eastern and Western Stations. Date. t OJ ^1 ATf and /^Tiv ATf — at™ is 11 I-. T' and T" // and 7" \{V-l") 1 S 3 S 1889. h. m. s. m. s. m. s. m. s. vt. s. s. San Juan del Sur . . Salina Cruz .... JMar. 3o{ N. L. E. W. 12 13 — 13 16.628 7 49- 636 +54 33-008 73 73 -17 19-593 -17 18.875 +37 13-415 + 37 14-133 +37 13-774 0-359 San Juan del Sur . Salina Cruz .... JMar. 3.{ N. L. E. W. 13 18 -0 13 12.949 7 46- 439 +54 33- 490 72 73 — 17 19-946 — 17 19-237 +37 13-544 +37 14-253 +37 13-898 0-354 San Juan del Sur . . Salina Cruz JApr. ■{ N. L. E. W. 12 14 -0 13 8.327 7 42. 727 +54 34- 400 69 73 —17 20.567 — 17 19. 865 +37 13-S33 + 37 I4-S3S +37 14- 184 0-351 San Juan del Sur . . Salina Cruz .... }Apr. JNov. N. L. N. L. E. W. E. W. 12 17 12 16 — +0 +0 13 4-053 7 39- 156 14 55- 285 S 39- 255 +54 35- 103 +9 16.030 64 68 71 72 — 17 21. 630 — 17 20. 905 +0 34-050 +0 34-51° +37 13-473 +37 14- 198 + 9 50. 080 + 9 50- 540 +37 13-836 0. 362 +37 13-923 St. Nicolas Mole .... Santiago de Cuba + 9 50.310 0.230 St. Nicolas Mole . . . Santiago de Cuba . . . 1 Nov. =H N. L. E. W. 12 17 +0 +0 14 56- 983 5 42. 148 +9 14-835 69 71 +0 35. 202 +0 35.666 + 9 50-037 + 9 50- 501 + 9 50- 269 0. 232 St. Nicolas Mole . . Santiago de Cuba . . JNov. 3o{ N. L. E. W. 13 IS +0 +0 14 58. 507 5 44- 959 +9 13-548 66 72 +0 36- 545 +0 37-021 + 9 50-093 + 9 50- 569 + 9 50- 331 0.238 St. Nicolas Mole . . . Santiago de Cuba . . JDec. ■{ N. L. E. W. 12 14 +0 +0 14 59. 867 5 47-995 +9 11.872 62 66 -(-0 38. 160 +0 38. 660 + 9 50-032 + 9 50. 532 + 9 50. 282 0. 250 St. Nicolas Mole . . Santiago de Cuba . . JDec. K N. L. E. W. 12 14 +0 +0 IS 1. 116 5 51-167 +9 9-949 72 72 +0 40- 055 +0 40- 529 + 9 50.004 + 9 50.478 + 9 50- 241 0.237 St. Nicolas Mole . . . Santiago de Cuba . . . JDec. JDec. .4 N. L. L. N. E. W. E. W. 12 14 12 12 +0 +0 +0 +0 15 2. 166 5 S3- 63s 26 54- 394 IS 13-437 +9 8.531 + 11 40.957 70 72 73 72 +0 41-475 +0 41.961 —0 54.672 -0 55-115 -f 9 50. 006 + 9 50.492 + 10 46.285 + 10 45-842 + 9 50- 249 0-243 + 9 50. 280 Port Plata . . . St. Nicolas Mole . + 10 46.064 0. 222 Port Plata . . . St. Nicolas Mole . JDec. < L. N. E. W. 7 12 +0 +0 26 56. 689 IS IS- 161 + 11 41-528 72 66 —0 55. 122 — 55. 612 + 10 46. 406 + JO 45-916 + 10 46. 161 0.24s Port Plata . . . St. Nicolas Mole . JDec. ,.{ L. N. E. W. 12 12 +0 +0 26 58. 687 15 16.549 + 11 42. 138 74 73 -0 55-833 -0 56.323 + 10 46-305 + 10 45-815 + 10 46.060 0.245 Port Plata . . . St. Nicolas Mole . JDec. ■'{ L. N. E. W. 15 14 +0 +0 27 5. 080 15 22. 002 + 11 43-078 71 68 —0 56.650 —0 57.126 + 10 46. 428 + 10 45-952 + 10 46. 190 0.238 Port Plata . . . St. Nicolas Mole . . JDec. -{ L. N. E. W. 13 12 +0 +0 27 7. 120 15 23. 669 + 1! 43-451 70 68 -0 57.068 -0 57- 541 + 10 46.383 + 10 45.910 + 10 46. 146 0. 236 + 10 46. 124 122 TELEGRAPHIC DETEEMINATION OF LONGITUDES Differences of longitude deduced from exchange of time signals — Continued. Eastern and Western sta- tions. Santo Domingo Port Plata . . Santo Domingo Port Plata . . Santo Domingo Port Plata Santo Domingo Port Plata . . Santo Domingo Port Plata Curasao. . . . Santo Domingo. Curasao. . . . Santo Domingo. Curacao .... Santo Domingo. Curasao. . . . Santo Domingo. Cara^ao . . Santo Domingo. Curasao .... Santo Domingo. La Guayra . . Santo Domingo La Guayra . Santo Domingo La Guayra Santo Domingo La Guayra Santo Domingo Date. 1890. I Jan. 2 }jan. 3 I Jan. 4 }>n. 5 I Jan. 6 }jan. I Jan. }jan. }jan. 23 an. 24 25 Feb. . Feb. 8 Feb. 10 > I Feb. II I N. L. N. L. N. L. N. L. N. L. )-4 t 1 c i2 E. 12 W. 10 E. 13 W. 10 E. 13 W. II E. II W. 12 E. 12 W. II E. 15 W. 12 E. 12 W. 12 E. 14 W. 12 E. 13 W. 12 E. IS W. 12 E. IS W. 12 E. 14 W. 12 E. 13 W. 12 E. 13 W. 12 E. 13 W. 13 [\^e and l^Tw +0 29 +0 27 +0 29 +0 27 +0 29 +0 27 +0 29 +0 27 +0 29 +0 27 J. 41. 546 3S-63I 42. 806 37. 293 43- 774 39- 225 45- 326 41-359 46. 765 43- 523 +0 35 +0 30 +0 35 +0 30 +2 35 +0 3° +0 35 +0 30 +0 35 +0 30 +0 35 +0 30 +0 44 +0 30 +0 44 +0 30 +0 44 -f o 30 +0 44 +0 30 27.911 7-361 30. 68s 33- 143 10. 428 35-694 II. 821 38. 497 13.284 41-257 14.712 697 905 97! 379 689 736 292 894 ^T(f — /\T'w m. s. + -i 5- 915 + 2 5.513 + 2 4.549 + 2 3.967 + 2 3.242 + 5 20.550 + 5 21.797 + 5 22.715 + 5 23.873 + 5 25-213 + 5 26.545 +13 43-792 + 13 43-592 + 13 43-953 + 13 44-398 o E 67 70 67 73 70 73 67 68 72 69 71 71 70 69 69 72 69 73 72 67 69 73 66 67 69 64 73 73 67 69 T' and T" + 1 8.189 + 1 8.654 + 1 8.617 + 1 9. 106 + i 9.421 + 1 9.823 + 1 10.354 + 1 10. 750 + 1 10.846 -fi 11.320 34- 150 34-781 35-335 35.906 36. 291 36. 866 37.420 37-99' 38. 740 39- 344 40. 099 40. 664 782 448 754 425 042 694 403 079 V and 1" m. s. + 3 14 + 3 14. + 3 14 + 3 14 + 3 i3' + 3 14 + 3 14 + 3 14 + 3 14 + 3 14. 104 569 130 619 970 372 321 717 088 562 + 3 46.400 + 3 45- 769 + 3 46-462 + 3 45- 891 + 3 46-424 4- 3 45-849 + 3 46- 453 + 3 45. 882 + 3 46-473 + 3 45- 869 + 3 46-446 + 3 45. 881 +11 48 + 11 47 + 11 47 + 11 47 + 11 47 + 11 47 + 11 47 + 11 47 010 344 838 167 911 259 995 319 % (^'+^'0 m. s. + 3 14- 336 + 3 14-374 + 3 14-171 + 3 14-519 + 3 14-325 + 3 14-345 + 3 46.084 + 3 46. 176 + 3 46- 136 + 3 46. 168 + 3 46- 171 + 3 46- 164 + 3 46- 150 + 11 47.677 +11 47.502 + " 47.585 + 11 47.657 + 11 47.605 s. 0.232 0.244 o. 198 0.237 0.316 0.286 0.288 0.286 o. 302 o. 282 0-333 0.336 0.326 0-338 IN MEXICO, CENTRAL AMEiiiCA, THE WEST INDIES, ETC. 123 RESULTING LATITUDES AND LONGITUDES. COATZACOALCOS. The latitude of the Coatzacoalcos transit pier, as determined by thirty-one observations of pairs of stars, is North i8° 8' 46". 19. The telegraphic difference of longitude between the transit piers at Vera Cruz and Coatza- h. m. s. coalcos, the mean of six independent measurements, is - o 6 54.672 The longitude of the pier at Vera Cruz, as determined in 1883 by Commander C. H. Davis, U. S. Navy, is - - - ^ 24 33.974 Longitude of Coatzacoalcos pier 6 17 39.302 To reduce the position of the transit pier to the position of the liglit-house, a correction of +10". 11 must be applied to the latitude and — o^ 193 to the longitude. (See description of stations.) Applying these corrections gives — r Lat. N. 18° 8' 56".3o Light-house < Long. W. 6'' 1 7"^ 39'. 1 09 ( Or in arc 94° 24' 46". 635 SALTNA CRUZ. The latitude of the Salina Cruz transit pier, as determined by twenty-eight observations of pairs of stars, is North 16° 10' 6". 74. The telegraphic difference of longitude between the transit piers at Coatzacoalcos and h. m. s. Salina Cruz, the mean of six independent measurements, is o 3 5.1 78 The longitude of the pier at Coatzacoalcos is 6 17 39.302 Longitude of Salina Cruz pier 6 20 44.480 To reduce the position of the transit pier to the position of the observation spot on the summit of the Morro de Salinas, a correction of — 30". 83 must be applied to the latitude and -f 4^.586 to the longitude. (See description of stations.) Applying these corrections gives — C Lat. N. 16° 9' 35".9i Observation spot on summit of Morro de Salinas < Long. W. 6" 20"" 49^.066 I Or in arc 95° 12' 15" 990 124 TELEGRAPHIC DETERMINATION OF LONGITUDES LA LIBERTAD. The lutitude of the transit pier at La Libertad was not determined. The telegraphic difference of longitude between the transit piers at Salina Cruz and Lg, h. m. s. Libertad, the mean of six independent measurements, is o .23 27.318 The longitude of the pier at Salina Cruz is - . ^ . . . . 6 20 44 480 Longitude of La Libertad pier 5 57 1 7. 162 To reduce to the position of Lieutenant Laird's pier used in 1884 there must be applied. .+ 0,030 Longitude of Lieutenant Laird's pier, depending on Salina Cruz 5 571 7.192 Longitude of Lieutenant Laird's pier, depending on Panama 5 57 1 7-375 The difference between the two telegraphically determined longitudes of Lieutenant Laird's pier is o. 1 83 To reduce the longitude of Lieutenant Laird's pier to that of the inshore end of the iron wharf there must be applied a correction of +0.^098. (See Telegraphic Longitude Report of 1883-84.) Applying this correction gives — C Long. W. 5'' 57" i7'.290 ■ ^ Or in arc 89° 19' 19". 350 Lishore end of iron wharf \ /^ •__ _ _ o o SAN JUAN DEL SUR. The latitude of the San Juan del Sur transit pier, as determined by twenty observations of pairs of stars, is North 11° 15' 5". 63. The telegraphic difference of longitude between the transit piers at Salina Cruz and San h. m. Juan del Sur, the mean of four independent determinations, is. - - .. 037 13.923 The longitude of the pier at Salina Cruz is 6 20 44.480 Longitude of transit pier at San Juan del Sur .. -. 5 43 30.557 To reduce the position of the transit pier to the position of the signal station, a correction of — 21". 04 must be applied to the latitude and +I^4I3 to the longitude. (See description of stations.) Applying these corrections gives — ( Lat. N. 11° 14' 44". 59 Signal station .- < Long. W. 5'' 43"" 31' 970 • ( Or in arc 85° 52' 59".550 ST. NICOLAS MOLE. The latitude of the transit pier at St. Nicolas Mole, as determined by fifty-two observations of pairs of stars, is North 19° 49' I4".96. The telegraphic difference of longitude between the transit piers at Santiago de Cuba and h. m. s. St. Nicolas Mole, the mean of six independent determinations, is. , o 9 50.280 The longitude of the transit pier at Santiago de Cuba, depending on the position determined by Commander F. M. Green, U. S. Navy, in 1874, is .. . . .* 5 3 21.953 Longitude of transit pier at St. Nicolas Mole _ 4 53 31.673 To reduce the position of the transit pier to that of the flagstaff at Fort St, George, there must be applied to the latitude a correction of +0" 10 and to the longitude +0^.780. Applying these correction's gives — Flagstaff at Fort St. George Lat. N. 19° 49' i5".o6 Long. W. 4*' 53"" 32'.453 Or in arc 73° 23' 6".795 IN MEXICO, CENTRAL AMEEIOA, THE WEST INDIES, ETC. 125 poirr PLATA. The latitude of the transit pier at Port Plata, as determined by twenty-one observations of pairs of stars, is North -19° 48' 46". 15. The telegraphic difference of longitude between the transit piers at St. Nicolas Mole and h. m. s. Port Plata, the mean of five independent determinations, is ._ o 10 46.124 The longitude of the transit pier at St. Nicolas Mole is ... . . . 4 53 3 1-673 Longitude of transit pier at Port Plata _ . . . . . 4 42 45.549 To reduce the position of the transit pier to that of the light-house, a correction of -|-4".68 must be applied to the latitude and +o^2I8 to the longitude. (See description of stations.) Applying these corrections gives — { Lat. N. 19° 48' 5o".83 Light-house < Long. W. 4'' 42"" 43^-7^7 (Or in arc 70° 41' 26". 505 SANTO DOMINGO. The latitude of the transit pier at Santo Domingo, as determined by forty-five observations of pairs of stars, is North 18° 28' 5". 10. The telegi'aphic difference of longitude between the transit piers at Port Plata and Santo h. m. s. Domingo, the mean of five independent determinations, is . . o 3 14.345 The longitude of the transit pier at Port Plata is ... .... 4 42 45.549 Longitude of transit pier at Santo Domingo 4 39 31.204 To reduce the position of the transit pier to that of the light-house, a correction of — 1 1".46 must be applied to the latitude and +o''-74^ to the longitude. (See description of stations.) Applying these corrections gives — r Lat. N. 18° 27' 53".64 Light-house < Long. W. 4'' 39™ 3 1^952 ( Or in arc 69° 52' 59". 280 CURAgAO. The latitude of the transit pier at Curasao, as determined by fourteen observations of pairs of stars, is North 12° 6' 2i".92. The telegraphic difference of longitude between the transit piers at Santo Domingo and h. m. s. Cura9ao, the mean of six independent measurements, is : o 3 46.150 The longitude of the transit pier at Santo Domingo is 4 39 31.204 Longitude of transit pier at Curasao , 4 35 45.054 To reduce the position, of the transit pier to that of Rif Fort light-house, a correction of — 1".83 must be applied to the latitude and +o^763 to the longitude. Applying these corrections gives — Lat. N. 12° 6' 2o".09 Rif Fort light-house- ^ Long. W. 4" 35" 45'-8i7 Or in arc 68° 56' 27". 255 126 TELEGiiAPHIG UETKRMINATION OF LONGITUDES LA GUAYRA. Tlie latitude (^f the transit pier at La Guayra, as determined by fourteen observations of" pairs of stars, is North 10° 36' 53". 69. The telegraphic difference of longitude between the transit piers at Santo Domingo and h. m. s. La Guayra, the mean of four independent determinations, is o 11 47.605 The longitude of the transit pier at Santo Domingo is 4 39 3 1.204 Longitude of transit pier at La Guayra 4 27 43.599 To reduce the position of the transit pier to that of the light-house near the breakwater, a correction of +3". 66 must be applied to the latitude and -f o^772 to the longitude. (See description of stations.) Applying these corrections gives — rLat. N. 10° 36' 57"-35 Light-house near breakwater .. .. < Long. W. 4^ 27™ 44^37I ■ ( Or in arc 66^ 56' 5".565 VERA CRUZ ; r-^v ! \ 1 • *r 22 M yi M-n. ,1) b^ ^'^ - J JJ tV,ra' I VcIRf,. IS 21 ^54 k 20 19 ii li'' iV i 16 "t; O.Sh ii' -■1 «i«,,S' .1»"''. ■Pt Colli a , '•* ■'H., '* ' V /r / ,.i S-. M2i *r-^ ."^.CP 9 9" l4 i. VERA CRUZ 'ioi 1 ,' ft X, 6' ^ I't.MoCAJQXl 7<^-ijrn,J{ytlroqrafih.ic Office ChuTrtNo. 9 67 COATZACOALCOS RIVER 4 4l fne.gy.S.Sh Frerrrv ^■ctrogrtgihijC! Office Chart J/b.lCUtB SALINA CRUZ "A'^. f'^ "- » 8i JO ' 8i 8t fli f.-^ Si ^^ 7^ 1 8 9i / II i„'''V^- 8* 7i , '^''2/ 11 JJSr^ 9i Cji TJ^y 8i ,\ „, 5? 6 6 ^ ' J' JO 9 ^M 9i 9 10 9i » 9r J2 11 10 i2^ V. 9r^ 9? si , o 9i 8 9i '■' f>1 ig »i si- ^.- " . si f- 10 10 - _ 9i 30 13 m 12 13 12 16 IS From HydrograjjTdc Of'f%ce Chart No. 876 LA LIBEETAD 3 ^i 3 i ^ ^ . , 6 31 5i 4i SSK 2i 6t 7 6i 5i 2i«>'-' 3i 2i a 5i Iff'.'bh.S 6i S 6i 6^ 8* 9i 8i 84 84. 94 84 64 84 Ik 6 T 8 8 n 1 84 ni 74 gy.hh. S 8 74 8 ^ 84 8 ay M.J 74 84 yy fcfc. A" 8j 84 94 94 95 —.10,^ Ik.S (4 94 94 84 10 94 94 gy.bh,S 94 9i 9i ..J«- io4 10. 94 94 -lb /'' io4 10--.. 10. 10" / 1 \ \ 94 \ I j .• 10 •To From JfyAroffrajahic Office CTuiTt -Xb ■ 939. SAN JUAN DEL SUR Ftotti Ifydrocfraphic Office Chartl^b 93't SANTIAGO DE CUBA 4*4 41*' , I 11.]^ ■otS 'Jp^ , o *• -''If. ..."■■•'»'«(» J;t'' Wj,rf«il" \ 11 JfjJ ,6^ "-^^t SkSTIt'I .it a* i? a H ii 3f u ij « 4i 4? ■?? 3^ i f3|^STR0fHj^l|(te»I.OBS SPOT *! p « 4 ^.^ life., ' » ••l t 'I t From Hydro(jraj)hic OFfice Chart ^n 1003 ST. NICOLAS MOLE ^am J^/vtroqrc^hic Office Chcert N'o. B50 PORT PLATA ■ ^ ,/'■■- ^.v**''' 6i 5i /" <'-^t; 3 \ 3? /^. \ ,., ' ■■■■V^^.. •2i .3 TT'o/n. KyArographic Office Chart Wo. 959 SANTO DOMINGO Basttoit ofLa. ComoerpcW] 5i 54' 5 ..4 5. 5 44 ■I 54 r.4 54 -.44 54 54 6i 64 ^ ' 7i 74 ^ #^om :HxdTocrraphic Office Cha>t 2^o. 9/J^ SANTA ANA, CURAC^AO ■r^^^jy^'^ ■■'^^^iSk PoS^ ^r^ '' a^^* - — ^ ^ ^° 11^^ m 17 3i0 2? ^^2S IS 24 JT' ,i ^, .....34 jyanv Hydrop-c^Mc, Office C?uart2^o.lOi9 LA GUAYRA 20 S.Sh |r^r , ;i^ii#*iii«»*\ ^ " \ 4 '^ -^ *" * s=-- t % ■'-H->^V- • it'' //y^/ F— 7 ,. light :fixe4 while, "visajle. 7 miles .2%« ce>n,tem.plAtAd' Ttarbor impro\'errtArua cere- vnjBi>caub&A Jy hroh&rv Ixaes. FroTTi Hydjro^apMo Office ChcurtJVo, 992 APPENDIX The Constants of Kew Theodolite Magnetometer, No. 54, WITH THE Magnetic Observations and Results of the U. S. Telegraphic Longitude Expeditions OF 1888 and 1889, AND 1889 AND 1890, OBSERVED BY LIEUTENANT C. LAIRD AND Ensigns J. H. L Holcombe and L M. Garrett, U. S. N., under THE COMMAND OF LIEUTENANT J. A. NORRIS, U. S. N. Prepared for publication by G. W. LITTLEHALES, U. S, H YDROGR^^PHIC OFFICE, Under the direction of Lieutenant-Commander RICHARDSON CLOVER, U. S. N., HYDROGRAPHER. 127 GENERAL INTRODUCTION. During the year 1884 the U. S. Hydrographic Office was engaged in charting the area covered by the West Indies and the Caribbean Sea. More data were required for the deduction of the empirical lormuliv, based on general mathematical views, which would serve for the computation of the declination (or variation) at any geographical position within that area, and for extending the series of observed values at the important stations sufficiently to provide for the deduction of equations for predicting values of the declination and assigning rates of secular change. In accordance with a scheme submitted by Mr. G. W. Littlehales, C. E., Assistant in charge of the Division of Chart Construction, the commanders of vessels of tlie North Atlantic Squadron were directed to make observations for the determination of declination at the ports visited by their vessels, and the expedition for the determination of telegraphic longitudes, then fitting out, was supplied with magnetic instruments for the determination of declination, dip, and horizontal force at the astronomical stations to be occupied. During the winter of 1 888-89, magnetic observations were made at Vera Cruz, Coatzacoalcos, and Salina Cruz, Mexico ; similar observations were made at Port Plata, San Domingo, and Cura9ao, West Indies, and at La Gruayra, Venezuela, during the winter of 1889-90. The observations were made during the first season's work by Lieut. Charles Laird and Ensign J. H. L. Holcombe. Ensign Holcombe was reheved by Ensign L. M. Garrett in the fall of 1889. The instruments furnished the expedition were a Kew unifilar magnetometer and a Barrow dip circle. The magnetometer, when in use, was supported by a tripod stand similar to that used by photogra- phers; three radial V-grooves supported the leveling screws which form the feet of the instrument. The dip circle was set up on a solid pier built of brick and cement. At all stations except Vera Cruz the in- struments, after being mounted, were not dismounted until after the completion of the observations at the station. At Vera Cruz and Coatzacoalcos one of the observing tents designed by Lieut. J. A. Norris was used to cover the instruments. At the other stations a wall tent, the pins and mountings of which were made of copper, was used. Independent sets of altitude and time azimuths were taken with a theodolite for the determination of the azimuth of the mark. DESCRIPTION OF THE STATIONS, The site selected at Vera Cruz, Mexico, was in the Plaza Baluarte, near the intersection of the Calle de Ocampo and the Avenida de la Playa, Lat. N. 19= 12' 2" Long.W. 96° 7' 25" At the other stations the magnetic instruments were set up near the spot at which the astronomical observations were made. A description of these astronomical observation spots is given in that portion of the report referring to the telegraphic determination of longitudes. At Coatzacoalcos, Mexico, the magnetic station bore 207 feet due north of the transit pier, Lat. N. 18° 8' 48" Long W. 94° 24' 49" 129 21124—11^0. 97 9 I BO MAGISETIO OBSERVATIONS. At Salina Cruz, I\[exico, tlie site selected was N. 15° W. distant 278 feet from the astronomical observation spot, Lat. N. 16° 10' 8" Long.W. 95° 11' 8" At Port Plata, San Domingo, the magnetic instruments were set up 96 feet N. 'T]^ W. from the center of the transit pier, Lat. N. 19° 48' 46" Long.W. 70° 41' 23" The site selected at Cura9ao, West Indies, was in the open space in front of the governor's mansion ; the instruments bore W. 24° S. distant 68 feet from the observation spot, Lat. N. 12° 6' 21" Long.W. 68° 56' 16" At La Guayra, Venezuela, the magnetic instruments were set up in the vacant lot to the eastward of the market, and bore from the center of the ti'ansit pier W. 35° S. distant 210 feet, Lat. N. 10° 36' 52" Long.W. 66° 55' 56" Calculation of the value of the horizontal component of the eartKs magnetic force from observations of vibration and deflection. T„r= observed time of one vibration of the magnet. Ti ^ time of vibration, corrected for rate of chronometer and arc of vibration. T ^z time of vibration, corrected for rate of chronometer, arc of vibration, temperature, torsion force of the suspending thread, and induction. S zr daily rate of chronometer, -|- when gaining, — when losing. oca' ^semiarc of vibration, at the beginning and end of the observation, expressed in parts of radius. — — ratio of the force of torsion of the suspending thread to the magnetic directive force. [This is obtained F h V ^ from the formula — rr where v zz the angle through which the magnet is deflected by F 90°— z; a twist of 90° in the thread.] g-zr the correction for the decrease of the magnetic moment of the magnet pi-oduced by an increase of temperature of 1° Cent. [This correction is not constant at all temperatures, and the correc- tion is more exactly expressed by aformula of the form — correction to t^ — qit^ — + 2'(^o~0^ t„ being the observed temperature and t an adopted standard temperature.] K z= Moment of inertia of the magnet, including its suspending stirrup and other appendages. [This is constant for the same magnet and suspension, but varies slightly with temperature, owing to the expansion of the materials.] 3- = ratio of the circumference to the diameter of the circle = 3. 141 5927. jj. = the increase in the magnetic moment of the magnet produced by the inducing action of a magnetic force equal to unity of the metric system of absolute measurement. /„ — apparent distance between the centers of the deflecting and suspended magnets in the observation of deflection. rizz distance corrected for error of graduation and temperature [r— r<,{ i +0.0000 18 (^„—o° Cent.)} + cor- rection for scale error.] u =. observed angle of deflection. P =: a constant, depending upon the distribution of magnetism in the deflecting and suspended magnets. [This is to be determined from several series of observations of deflection at two or more dis- tances. The most convenient distances to be employed are .3 and .4 of a metre. The correction is very small and may remain unapplied until the conclusion of the series.] MAGNETJO OBSERVATIONS. 131 mrzmaonetic moment of the deflecting or vibrating magnet. II = horizontal component of the earth's magnetic force. =: approxmiate value oi Ho II -,"= value of ^ before the application of the correction ( i — ) \ 86400 16/ V F ''*« / Wiiizz ih ir HA ^r/^^^" ^/ H Ii\ nV Let A = value of -- from deflection at the distance r H' and A' z= value of from deflection at the distance r' then P = H' A -A' A_A/ ^'2 r The quantity K is obtained by observing the time, of vibration of the magnet alternately with its usual mounting and with its moment of inertia increased by the addition of a gun metal ring or cylinder of known weight and dimensions. / P cP\ f- When a cylinder is employed the value of K is obtained from the'formula K— Wl 1- — 1 where W is the weight of the cylinder in grammes, / and d its length and diameter expressed in metres, t' and t being the times of vibration (corrected for torsion, temperature, etc.) of the magnet with and with- out the additional weight. Constants, coefficients, and corrections for the unifilar magnetometer No. 54, by Elliot Bros., London. Graduation of deflection bar : Apparent distance from center of instrument. True distance at temperature 0° Cent. 0.25 0.24993 0.30 0.29994 0.35 0.34994 0.40 0.39991 0.45 0.44991 Deflection apparatus, angular value of one scale division = 60^.45. Wlien the scale reading is above the middle point of the scale the correction to the circle reading is additive, and»when below it is subtractive. Vibration magnet, angular value of one scale division z= i'.8. The deflecting magnet employed is marked : 54A. The suspension magnet employed is marked : 54C. 132 MAGNETIC OBSERVATIONS. For deflecting magnet : Correction to o° Cent. = 0.000357 (^„ — 0°) + 0.00000 1 1 2 (^ — 0°)" Induction coefficient >u — o 000005 ; log. =14.72226. Log. ;r^K at 0° Cent. =: 9.44474. Dimensions of inertia cylinder: Length zz 0.0951 7 metres. Diameter = 0.00996 metres. Weight ^ 63.43 grammes. TABLES TO FACILITATE THE CALCULATION OF THE OBSERVATIONS. Table I. — / a/i/i.' of for different iniiial and terminal semiarcs of vibration, 16 Semiarc Semiarc at end of vibra'.ion. at com- mencement. 80' 70' 60' 50/ 40' 30/ / 100 0. 00004 0.00004 0.00003 0. 00003 0. 00002 0. 00002 90 0. 00004 0. 00003 0.00003 0. 00002 0. 00002 0. OOOOI 80 0. 00003 0. 00003 0.00003 0. 00002 0. 00002 0. OOOOI 70 0. 00003 0. 00002 0. 00002 0. OOOOI 0. OOOOI 60 0. 00002 0. 00002 0. OOOOI 0. OOOOI 50 0. OOOOI 0. OOOOI 0. OOOOI Table II. — Value of \-\- ^- for different values of the deflection produced in the F magnet by a twist of ijo° of the suspension thread. Effect of 90° of torsion. ■^1 Effect of 90° of torsion. ■ + ^: Effect of 90° of torsion. ■ + ^ / / / I 1. 00019 6 1. 001 1 1 II I . 00204 2 0. 00037 7 0. 00130 12 0. 00223 3 0. 00056 8 0. 00148 13 0. 00241 4 0. 00074 9 0. 00167 14 0. 00260 5 0. 00093 10 0. 00185 15 0. 00278 Table III. — Value of i 86400 chronometer employed. for different rates of the Daily Rate. Chronometer gaining. Chronometer losing. Sec. 5 0. 99994 1 . 00006 10 0. 99988 0. 00012 IS 0. 99983 0.00017 20 0.99977 0. 00023 25 0.99971 0. 00029 30 0. 99965 0. 00035 35 0. 99959 0. 0004 1 40 o- 99954 0. 00046 45 0. 99948 0.00052 50 0. 99942 0. 00058 Table YM .— Values of i-\-V^ for different distances. Distance. •+-: )-„» Metres. 0. 250 1 . 00068 0.300 I . 00039 0-350 1 . 00025 0. 400 1. 00016 0.450 1. 00012 MAGNETIC OBSEEVATIONS. 138 Table V. — Temperature corrections for the magnet 54 A. Temp. ('0). ( 'en:. Coireclion to 0° Cent. Temp. Co). Correction lo 0° Cent. Temp. Cent. Correction to 0° Cent. Cent. -5 —0. 00176 + 10 +0. 0036S 25 +0. 00962 — 4 —0. 00141 II 0. 00407 26 0. 01004 — 3 — 0. 00105 12 0. 00445 27 0. 01046 — 2 — 0. 00070 13 0. 00484 28 0. 01088 — I — 0. 00035 14 0.00522 29 0. 01 130 0. 00000 15 0. 00561 30 0.01172 + ' -|-o. 00036 16 0. 00600 31 0. 01215 2 0. 00072 17 0. 00640 32 0. 01258 3 0. 00109 18 0. 00680 33 0. 01301 4 0. 00145 19 0.00719 34 0.01344 5 0. ooi8i 20 0. 00759 35 0.0138; 6 0.00219 21 0. 00799 36 0. 01431 7 0. 00256 22 0. 00840 37 0.01475 8 0.00293 23 0.00881 38 0.01519 9 0.00331 24 0. 00922 39 0.01563 Table VI. — Value of Log. t^ K, and of Log. J^ r'^ for different temperatures. Temp. Cent. Log. TT^K. Log. yi ^. >-o=:Oi".250. ?-„^o".30o. 7o=ora.350. ro^o"i.400. ro = o'".45o 9.44474 7.89240 8. 13007 8. 33095 8. 50486 8. 65835 5 9.44479 7.89251 8. 13019 8. 33107 8. 50498 8. 65847 10 9- 44485 7. 89263 8. 1 303 1 8.33119 8. 50510 8. 65859 15 9. 44490 7.89275 8. 13042 8.33130 8. 50521 8. 65870 20 9. 44496 7. 89287 8. 13054 8.33142 8. 50533 8.65882 25 9.44501 7. 89298 8. 13065 8-33153 8. 50544 8. 65894 30 9. 44507 7.89310 8. 13077 8.33165 8.50556 8. 65906 35 9.44512 7. 89 22 8. 13089 8.33177 8. 50568 8.65917 40 9.44518 7- 89334 8. 13101 8.33189 8. 50580 8. 65929 Metal scale centigrade thermometer belonging to unifilar No. 54, hy Elliot Bros.., London {verified in a vertical position). Corrections to be applied to the scale readings, determined by comparison with the standard in- struments at the Kew Observatory. At 0° — o°.4 5° -o°.5 10° -o°.5 15° -o^5 20° — o°.5 25° — o°.4 30° -o°.3 Note I. — When the sign of the correction is +, the quantity is to be added to tlie observed reading, and when — , to be subtracted from it. 134 MAGNETIC OBSERVATIONS. Note II. — As mercurial thermometers are liable to read too high through age, this instrument ought to be again tested, at some future date, at the melting point of ice, and if its reading at that point be found different from the one now given, an appropriate correction should be applied to all the above points. Observations for azimuth of mark made at Vera Cruz, Mexico, at 5 p. m. January 7, 1889, by Lieut. Charles Laird, with Fauth instrument. Formula : tan» >i A = sin (s - (p) sin ( .; — h) cos S COS (.f — p) s = y2{

er 24, 1888, by Ensign J. H. L. Holcombe, witli ICew tlieodolite magnetometer No. 54, with long magnet surpended erect. Local time. u. m. h, in. 9 00 10 20 30 45 10 00 IS p. m. 1 53 15 30 45 2 00 15 30 45 50 Scale- readings. Left. Right. d. 40.8 41. o 41. o 41. 2 41. o 30 ! 40- 2 Mean. d. 41. I 41.2 41-4 41-5 41- I 40. 6 Line of detorsion. 40. 40.8 40.0 40.4 39-8 40. 39-4 40.4 39-8 40. 40. 40. 40.0 40. 2 40.4 40. 6 40.4 40. 2 39-9 39-9 39-9 40. o 40. I 40.5 a / // Azimuth circle, A 242 44 40 B 62 45 10 Remarks : Suspended torsion weight. Suspended magnet. Suspended torsion weight. o / // Azimuth circle, A 242 44 40 B 62 45 20 Remarks : Suspended magnet. Determination of scale value of magnet. Determination of axis of jjfiagnet. Scale. Circle read- ings, mean of Value of 10 divi- Scale. Scale read- ings. Mean. Alter- nate Axis. verniers. sions. mean. / // d. 10 243 40 40 E 40. 40. 40.00 15 32 30 I 14. 13.0 13-50 39.80 26. 65 20 23 10 17 30 E 39-2 40. 39.60 13-70 26. 65 25 14 20 18 10 I 15.0 12.8 13.90 39-40 26.65 30 05 30 17 40 E 37-4 41. 39.20 13-70 26.45 35 242 56 00 18 20 I 15.0 12. 2 13. 60 39-50 25-55 40 45 50 i8 40 E 38.4 41.^ 39.80 45 37 20 18 40 50 28 20 18 30 55 19 20 18 00 60 10 00 18 20 65 00 40 18 40 70 241 52 20 17 40 Value of one division of scale = i'.82. Scale reading of ax IS 26.39 40.70 Mean scale reading of east an d west magnetic elongation .... Reduction to axis . ■ • ■ 26. 04 152 44.97 ^ difference = 14-31 Azimuth circle rear s ... / // A 158 10 00 B 338 10 40 tions" . Magnetic meridian reads . At beginning of a. m. observa 153 II. 01 At end of p. m. observations Mean reading of mark , . . A 158 12 00 B 338 12 40 248 n.33 ^ 248 1 1 20 Azimuth of mark ^^ r. ofN. . 102 12. 35 145 58.98 7 T2 C\1 Marrnetic declina tion . . E MAGNETiO OBSEKVATIONS. 13'J Observations for declination made at Vera Cruz, Mexico, December 25, 1888 long magnet Line of detorsion 110°. , by Ensign J. H. L. Ilolcombe, wilh Kew theodolite magnetometer IS'o. 54, with suspended erect. I.oc.\l time. Scale- readings. Mean. / // Azimuth circle, A 242 44 40 I? 62 45 10 Determination of scale value of magnet. Determination of axis of magnet. a. m. Left. ; Right. Scale. Circle read- ings, mean of verniers. Value of 10 divi- sions. Scale. Scale read- ings. : Alter- h. m. 8 SO 9 00 ,/. d. ,/. Remarks : Suspended torsion weight. Suspended magnet. mean. 10 / // 243 39 40 E 39. 40. 2 39.60 d. IS 41.2 41.8 41- S ■S 31 20 I 14.5 12.0 13.20 39.65 26.43 30 41. 8 ; 42. 41.9 20 21 50 17 SO E 39. 2 40. 2 39.70 13.40 26.55 i '' 41.8 ' 42. 41.9 25 12 50 18 30 I 13.0 14.2 13. 60 39. 60 26. 60 10 OO 41. 5 41. 8 41-7 30 03 20 18 30 E , 39. 40. 39-50 13.50 26.50 IS i 41.2 41.4 41-3 Suspended torsion weight. 35 40 242 54 20 45 00 18 30 18 20 I i 13.8 13.0 13- 40 39-70 39.60 26. 50 E i9-o 40.4 p.m. Line of detor sion / // Azimuth circle, A 242 44 40 B 62 45 10 45 50 55 60 65 70 36 00 27 00 iS 00 09 00 241 59 40 50 20 18 20 18 00 18 00 18 00 18 20 18 40 1 00 IS 30 45 2 00 IS 39-8 40. 2 40.0 40.0 40. 2 40.8 40.4 40.4 40.8 41. 40-3 40.3 40. 2 40.4 40. 6 Remarks : Suspended magnet. Value of one division of scale = i'.82 Scale reading of axis . 26.52 Mean scale reading of east a Reduction to axis .... nd west magnetic elongation . 41.05 / 26. 59 = difference = 14.53 Azimuth circle rea ds 152 44.91 tions . f /f A 158 II 00 Magnetic meridian reads . At beginning of a. m. observa 153 11.50 B 338 II 40 At end of p. m, observations Mean reading of mark . A 158 12 20 B 338 13 00 \ 248 12.00 = 248 12 00 Azimuth of mark W. of N 102 12. 35 True meridian reads . . . 145 59-65 7 1 1. 81; E. 140 MAGNETIC OBSERVATIONS. Observations for dip made at Vera Cruz, Mexico, December IJ, 1888, by Lieut. J. A. Norris, and December 16, 1888, by Lieut. Charles Laird, with dip circle No. 84 and needle No. i. [Mean by polarities.] [Mean by polarities.] Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. s. N. / / / / / / / / 44 31 44 18 4405 44 03 44 43 4440 44 16 44 23 33 18 05 0: 42 38 15 22 32 18 05 02 42.5 39 '5-5 22.5 44° 25' 44° 03'. 5 44° 4o'-7 44° 19' 44° 1 4'. 3 44° 29'.8 Mean, 44° 22''.o Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N. / / / / / / / / 44 41 44 39 44 IS 44 23 44 27 44 13 44 00 43 57 44 42 11 iS 27 13 02 44 01 42-S 40.5 13 20.5 27 ■3 01 43 59 44° 4I'.5 44° l6'.7 44° 20' 44° 00' 1 Mean, 44° 19^.5 Resulting dip, 44° 2o'.9. 1 December 15,1888. Circle in Mag. prime vertical. Local time of beginning, 3:38 p. m. / Circle N. Needle N. 82 02 " S. 81 07 Circle S. " N. 82 05 " S. 81 18 Mean, 81 38 Polarity of marked end north. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. / 44 46 43 N. / 4400 00 / 43 S9 58 / 44 28 30 / 44 13 18 / 44 19 15 / 44 16 23 / 44 43 49 00 58.5 29 '5-5 17 195 445 46 43° S9'-2 44"^ 44° 22'.2 44° l8'.3 io'.7 44° Mean, 44° 2i''.2 44° 45/2 3i'-7 Polarity of marked end south. Circle west. Circle east. Face west. Face east. Face west. Face cast. S. N. S. N. S. N. S. N. / 4424 20 / 44 23 28 / 44 36 39 / 44 33 35 / 44 06 06 / 44 03 00 / 44 21 26 / 44 06 II 22 2S-S 37-S 34 06 oi.s 23-5 08.5 44° 23'. 7 44' 44° 3S'-8 29'-7 Mean, t 44° 03'.8 44° 4° I9'.8 44° i6'.o og'.g Resulting dip, 44° 20^.5. 1 December 16, 1888. Local time of beginning. 1 1:25 a. m. Local time of ending, i :oo p. m. Circle in Mag. prime . Circle N. Needle N. " S. Circle S. " N. " S. vertical. t> / 23 OS 23 58 18 14 19 06 Mean, 21 05 MAGJSETIO OBSERVATIONS. 141 Observations for dip made at Vera Cruz, Mexico, December 26, 1888, by Lieut. Charles Laird, with dip circle No. 84 and needle No. I. [Mean by polarities.] Polarity of marked end south. Circle east. Ciicle west. Face east. I'^ace west. Face ea.sl. Face west. S. N. / 44 17 16 S. / 44 04 04 N. S. N. 44 39 40 S. N. / 41 22 26 r 44 32 ' 30 / 44 01 01 / 44 40 41 / 44 13 17 31 16. 5 04 01 40- 5 39-5 15 24 44° 23'.8 44' 1 44° 02'.5 3'. I Mean, 44' 44° 40' 44° I9'-S 44° 29'.8 2 1 '.4 Polarity of marked end north. Circle west. Circle east. Face -west. 1 Face east. Face west. Face east. S. N. S. ' N. S. X. S. / 44 02 03 N. / 44 39 39 / 44 37 36 / 44 15 13 / 44 23 22 / 44 24 22 / 44 07 08 / 43 59 44 01 39 36.5 14 22.5 -3 07-5 02.5 00 44° 37'-8 44° 2 44° lS'.2 S'.o Mean, 44 44° i5'-2 44° c ° iS'.i 44° c 8'-3 i'-3 Resultii ig dip, 44° 1 9'. 8 December 26, Local time of beginning, 1:45 p. m. Local time of ending, 4:00 p. m. Circle in Mag. prime vertical. Circle N. Needle N. 15 46 S. 15 28 Circle S. " N. 15 59 S. 15 04 Mean, 15 34.25 142 MAGNETIC OBSEKVATIONS. Observations lor ileclination made at Coat^acoalcos, Mexico, February witli long Line of detorsion, go°. 4, 1889, by Ensign J. H. L. Holcombe, with Kevv theodolite magnetometer No. 54, magnet suspended erect. Local time. A. m. 8 35 50 9 05 20 35 p. m. 12 15 30 45 1 00 15 30 45 2 00 15 Scale- readings. Left. il. 38.9 39-4 39-2 39-2 39-0 Right. 40. I 39-6 39-8 39-6 39-4 Mean, o / // Azimuth circle, A 238 24 20 B 58 25 00 39.00 39-50 39-50 39-40 39.20 I Line of detorsion, 40 30.9 31-1 30.4 31-4 31-4 31-2 30.9 31.0 30. s 30.9 30-7 30-9 30-9 31.0 31.0 31-0 31.0 31.0 31.00 30.90 31.10 30-95 30.85 30.80 30.95 31.00 31.00 Remarks : Suspended magnet 8:20 a. m. Dismounted magnet. Suspended torsion weight. 0/1/ Azimuth circle, A 238 24 20 B 58 24 40 Remarks : Suspended magnet at 11:55 a. m. Determination of scale value of magnet. Determination of axis of magnet. Scale. Circle read- ings, mean of verniers. Value of 10 divi- sions. Scale. Scale read- ings. Mean. Alter- nate mean. Axis. / // d. u 239 20 30 E 40.0 40. I 40.05 10 02 20 iS 10 I 15.0 16. 9 15-95 39-77 27.86 20 238 43 30 18 50 E 39-0 40. 39.50 15.92 27.71 30 25 40 17 SO I 15.0 16.8 15-90 39-45 27.67 40 07 50 17 SO E 38-8 40.0 39-40 15.50 27.45 50 237 49 50 18 00 I 14. 16. 2 15. 10 39.20 27.13 60 30 50 19 00 E 38.0 40.0 39.00 70 13 00 17 50 80 236 55 00 18 00 70 237 13 00 i8 00 60 31 00 18 20 SO 49 20 18 00 40 238 07 20 18 30 30 25 50 18 00 20 43 50 18 40 10 239 02 30 17 30 20 00 Value of one division of scale = I'.Si. Scale reading of axis 27-57 35- 15 Mean scale reading of east ai id west magnetic elongation . . tions . / 13. 72 148 24.59 = difference = 7-58 Azimuth circle reads . . . . Magnetic meridian reads . At beginning of a. m. observa / // A 230 16 40 148 38.31 B 50 17 00 At end of p. m. observations A 230 14 40 Mean reading of mark . 140 15.91 B 50 IS 20 = 140 15 55 Azimuth of mark E. of N. 178 34.00 True meridian reads . . 141 41.91 M agnetic decline ition . 6 56.4 E. MAGNETIC OliSliKVATlONS. 143 Observations for declination ma.l. at Coatzacoalcos, Mexico, February 5, 1889, by Ensign J. II. L. Ilolcombe, with Kcw theo.lolit. magnetometer No. 54. with long magnet suspended erect. Line of detorsion, 90''. Local Sc ile- " time. read ings. / // Left. Right. Mian. Azinuuli circle, A 2jS 14 00 B 5S 14 40 a. m. h. III. d. d. U. Remarks : 8 35 39- « 41.2 40. 15 Swung magnet at 8:20. 50 39-9 40.8 40-35 9 OS 40. I 41. o_ 40-55 20 40. 2 41.0 40. 60 Torsion weight hung over night. 35 40. 6 41.0 40. 80 50 40. 8 41. 40.90 10 05 40.8 40.9 40.8s 20 40.5 40.9 40.70 40 40. 2 40.4 40.30 01// p. in. Line c f detorsion, 60 Azimuth circle, A 238 14*20 B 58 14 40 12 30 38-0 40.8 39-40 Remarks : Suspended magnet at 12.25. 45 38-4 39-9 39-15 I 00 38.9 39-2 39-05 15 39- 39-4 39.20 30 39- l. Holcombe, long magnet deflecting at right angles to short magnet suspended. Distance r = o'".44o. Circle readings. Circle readings. X, No. A. B. / // Mean. No. A. B. Mean. / // / // / // / // / // E. I 61 57 00 5640 5650 W. 2 56 06 20 6 20 6 20 E. 3 56 40 56 20 5630 W. 4 06 40 6 20 6 30 E. S 62 06 20 700 6 10 Mean, 6l° 59' 5°" 56° 06' 25'' W. 6 56 13 40 1340 '3 40 E. 7 62 03 00 300 300 W. 8 13 40 14 00 13 50 ■r. 1> E. 9 61 59 20 5900 59 10 •:^ W. 10 14 40 14 20 1430 Mean, 62° 01' 05" 56° 14' 00" Computation: — = ^r3sin u {\ — — ) / Magnet east, 2 w = 5 53. 41 Magnet west, 2 « = 5 47. 08 Mean, 5 50. 33 « = 2 55. 12 Sin u P Logarithms. 8. 62822 8- 70743 Time of beginning, 1:15 Time of ending, 2:20 Temp., 24. C. Temp., 25. 5 I — — temp., etc. m 0. 00749 0. 0041 1 Mean, 1:47 /■=24. 7 II 7- 34725 Distance r = o'".465. Circle readings. No. E. W. E. w. : E. I 5 A. B. / // / // 62 32 20 32 20 32 20 32 20 32 20 32 20 Circle readings. Mean. No. A. B. Mean. / // / // / // / // 32 20 2 57 35 20 35 40 35 30 32 20 4 35 20 35 20 35 20 32 20 Mean, 62° 32' 20'' o ,c/ ,c// 57° 35' 25 W. E. W. E. W. 62 29 00 29 20 29 20 29 00 29 10 29 to 6 57 34 00 S I 33 40 10 34 00 3420 3400 3400 34 10 Mean, 62° 29' 10' 57° 34' 00" Computation : H = \ r-' sin « (I ■ o / Magnet east, 2^ = 4 56. 91 Magnet west, 2 » = 4 55.17 Mean, 4 56. 04 « = 2 28. 02 Time of beginning, 8:34 Time of ending, 9:20 Mean, 8:57 Temp., 24. 5 C. Temp., 25. 6 /=25. o i'- :i Sin " P I - r'- temp. etc. m * II Logarithms. 8. 70194 8. 63390 o. 00437 o. 00419 7-3444° 150 MAGNETIC OBSERVATIONS. Observations for horizontal intensity by the method of deflections -with Kew theodolite magnetometer No. 54, at Coatzacoalcos, Mexico, Febi-uary 11 and 12, 1889, by Ensign J. H. L. Holcombe, long magnet deflecting at right angles to short magnet suspended. Distance r^d^.^So. Distance y=.o'".385. ■a c Circle readings. Circle readings. 'A No. A. B. Mean. No. A. B. Mean. t It / // / // 1 /f / // / // E. I 64 35 40 36 00 35 SO W. 2 55 29 40 2940 2940 ^• E. 3 34 40 3500 3450 C4 W. 4 29 00 29 20 29 10 E. 5 34 40 3500 3450 Mean. 64° 35' \o" 55° 29' 25" W. 6 55 26 40 26 40 26 40 E. 7 64 27 20 27 20 27 20 W. 8 26 00 26 20 26 10 (LI E. 9 26 20 26 40 26 30 > W. 10 26 20 26 40 2630 Mean, 64° 26' 55" 55° 26' 27'' m P Computation: — = \r''%\Ti.u{\— — ) / Logarithms, Magnet east, 2 ?!■ = 9 05. 75 Magnet west, 2 k = 9 00. 47 \r^ 8. 43589 Mean, 9 03. II Sin « 8.89712 « = 4 3J-5S P I — — 0. 01037 Time of beginning, 9:45 Temp., 25. C. temp., etc. 0. 00428 Time of ending, 10:45 Temp., 25. 7 m Mean, 10:15 (■=25.4 H 7. 34766 0) C "A Circle readings. Circle readings. No. A. B. Mean. No. A. B. Mean. / // / // / // / // / // / // E. I 64 25 00 25 00 25 00 W. 2 55 42 20 42 20 42 20 E. 3 24 40 2440 2440 W. 4 42 20 4240 4230 E. 5 24 40 2440 2440 Mean, 64° 24' 47" 55° 42' 25'/ W. 6 57 38 40 3900 3850 E. 7 64 19 40 1940 1940 W. 8 38 40 3900 3850 U5 E. 9 19 20 19 20 19 20 W. 10 39 00 3920 39 10 Mean, 64° 19' 30" 55° 38' 57" Computation: — = i7-:'sin u H <-:.--) / Magnet east, 2 » = 8 42. 37 Magnet west, 2 ?< = 8 40. 55 \r^ Logarithms. 8. 45339 Mean, 8 41. 46 « ^ 4 20. 73 Sin u P 8. 87950 Time of beginning, 12:15 Time of ending, 12:55 Temp., 30 Temp., 30 c. .8 temp., etc 0. 00636 0. 005 1 6 Mean, 12:35 ;■ = 30. 4 H 7- 34441 MAGNETIC OBSERVATIONS. 151 Observations of vibration, made at Coatzacoalcos, Mexico, February 8, 1889, by Ensign J. H. L. Holcombe. Civil time, a. m. Temp, of magnet. Hor. force magnetometer. Hor. force thermometer. h. m. At commencement 3 20 73-4 F. At end Means Correcte 3 45 73-2 73.3 d means . Scale moving apparently — Torsion force. To the right To the left. No. of Time of Time of No. of Time of Time of Torsion. Scale divi- -Means and differ- Vib. passmg wire. I So Vib's. Vib. passmg wire. I So Vib's. sions. ences. h. m. s. m. s. h. m. s. VI. s. 9 39 55- 9 9 40 25. 40. 00 180 49 56. 7 10 I. 7 189 50 26. 7 10 1.7 + 90 41-55 18 40 55. 27 41 25. I 40.50 For 90°. 198 50 57.0 10 2. 207 51 27.0 10 I. 9 — 90 39-40 36 41 55-3 45 42 25.4 40.00 216 51 57- I 10 1.8 225 52 27. I lo I. 7 +360 44-50 For 360°. 54 42 55- 5 63 43 25. 5 40. 10 For 90°. 234 52 57- 3 10 1.8 243 53 27.3 10 1.8 -360 36.00 Adopted effect 90°. 72 252 43 55- 7 53 57- 4 10 1.7 81 261 44 25.7 54 27. 5 10 I. 8 40.30 Torsion l.loSc.Div. z'=i'.98 I Sc. Div. = i'.8. 90 44 55-7 99 45 25.9 h 270 54 57- 7 10 2. 279 55 27.7 10 1.8 i + - = i. 00037 90 5 0.7 99 50-9 Vertical scale, 18. 6 9 Time for 1 80th. 49 56.4 Time for 189th. 50 26.8 Mean 10 1.83 Time, 90 Vib. 10. 178 Mean tir ne — I So vib's 60P.80 Time, I Vib. =T„= 3°-343 152 MAGNETIC OBSERVATIONS. Observations of vibration, made at Coatzacoalcos, Mexico, February 9, 1889, by Ensign J. H. L. Holcombe. Chro. error, Daily rate, + 2".234- Civil time. Temj . of magnet. Hor. force magnetometer. Hor. force thermometer. At commencement . h. m. 2 30 27.5 C. At end . . Means Corrected means . 3 05 30-4 28.95 28.7 Scale moving apparently — ] To the right. To the left. No. of Vib. Time of passing wire. Time of 180 Vib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scale divi- sions. Means and differ ences. h. m. s. 9 II 08. tn. s. 9 h. m. s. 9 II 38. 2 m. s. 40. 10 180 21 10. 5 10 2. 5 189 21 40. 7 10 2. 5 + 90 41-30 18 12 08. 2 27 12 38. 3 40. 10 For 90°. 198 22 10. 7 10 2. 5 207 22 40. 9 10 2. 6 — 90 38.95 36 13 08.4 45 13 38. 5 40.05 216 23 II. 10 2. 6 225 23 41.2 10 2. 7 +360 44.90 For 360°. 54 234 14 08. 5 24 II. 2 10 2. 7 63 243 14 39- 24 41. 5 10 2. 5 —360 40.50 37.00 For 90°. Adopted effect 90°. 72 252 90 270 15 09. 25 II. 7 16 09. 3 26 12. I 10 2. 7 10 2.8 81 261 99 279 15 39-2 25 41.9 16 39- 5 26 42. 2 10 2.7 10 2. 7 40. 10 Torsion 1.03 Sc Div. z;=l'. 85 I -|— = I. 00034 F I Sc. Div. =i'.8 90 99 9 Vertical scale, 16 Time for 1 80th. Time for 1 80th. Mean 10 2. 63 Time, 90 Vib. 10 02. 61 Mean time — 180 Vib's 602=. 62 Time, 1 Vib. = To = 3'- 348 MAGNETIO OBSERVATIONS. 153 Observations of vibration, made at Coatzacoalcos, Mexico, February lo, 1889, by Ensign J. H, L. Hokombe. Chro error. Daily rate, +2'.i.j4. - Civil time. Temp, of magnet. 1 loi". force magnetom eter. Hor. force thermometer. At commencement . h. 3 m. 35 26.3 C, At end A) cans Corrected means . 4 12 26. 2 26. 25 25-9 Scale moving apparently — Torsion force. To the right To the left. No. of Vib. Time of passing wire. Tmie of 180 Vib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scale divi- sions. Means and differ- ences. h. m. s. lb 17 36. 2 in. s. 9 A. m. s. 10 18 06. 5 m. s. 40.05 180 27 38- S 10 2. 3 189 28 08. 4 10 I. 9 + 90 41. 00 18 18 36. 4 27 19 06. 7 40. 00 For 90° 19S 28 38. 7 10 2.3 207 29 08. 7 jo 2. - 90 39. 00 36 19 36. 7 45 20 06. 8 39-9° 216 29 39- 10 2.3 225 30 09. I 10 2.3 +360 44-75 For 360° 54 20 36. 8 63 21 07. I 40. 00 For 90° 234 30 39- 3 10 2. 5 243 31 09. 2 10 2. I —360 35-50 Adopted effect go° 72 252 90 21.37- 3' 39- 22 37. 2 5 3 10 2.3 81 261 99 22 07. 2 32 09. 4 23 07. 4 10 2. 2 40. IS Torsion 1.13 Sc.Div. ■Z' = 2'.C h 3 I Sc. Div. = I' 8 270 32 39- 7 10 2. 4 279 IZ 09- 5 10 2. I Vertical I. 00037 99 9 scale, 24. Time for 1 80th. Time for 189th. Mean, 10 2. 35 Time, 90 Vib. 10 2. 10 Mean time — 180 Vib's 6o2».225 Time, I Vib. = T„ = 3'-346 154 MAGNETIC OBSERVATIOKS. Observations for declination made at Salina Cruz, Mexico, March 21, 1889, by Ensign J. H. T>. Tlolcombe, with Kew theodolite magnetometer No. 54, with long magnet suspended erect. Line of detorsion, iSo**. l.occil time. h. m. 8 35 8 50 9 05 9 20 9 35 9 50 10 05 10 20 •o 35 10 so 11 05 II 20 p. m. I 00 I 15 1 30 ' 45 2 00 Scale readings. Left. Right. d. 40. o 40.0 40. I 40. 2 40.8 40,9 40.8 40.8 40.8 40. 6 40.5 40.4 Mean. d. 40. o 40. I 40. 2 40.4 41. o 41. 1 41.0 41.0 40.9 40.8 40.8 40-5 d. 40. 00 40.05 40. 15 40.30 40. 90 41. 00 40. 90 40. 90 40.85 40.70 io-65 40.45 Line of detorsion, 200 38.0 38.4 38.0 38.2 38.0 38.2 38.1 38.2 38.5 38.9 38.20 38.10 38.10 38-15 38.70 Azimuth circle, A 248 37 20 B 68 37 40 Remarks ; Suspended torsion weight at 7:40. Suspended magnet at 8; 20. Suspended torsion weight. Azimuth circle, A 248 37 00 B 68 37 40 Remarks : Suspended magnet at 12:50. Change in overhead scale of II div. In morning read with horizontal wire at 10 d., now at 21. Determination of scale value of magnet. Determination of axis of magnet. Scale. Circle read- ings, mean of verniers. Value of 10 divi- sions. Scale. Scale read- ings. Mean. Alter- nate mean. Axis. / // d. 249 47 40 E 39-9 40. I 40.00 10 29 30 18 10 I 15-9 16. I 16.00 40.25 28.12 20 09 SO 19 40 E 39-8 41.2 40.50 16.45 28.47 30 248 52 50 17 00 I 16.8 17.0 16. 90 40. 20 28.55 40 34 40 18 10 E 39-8 40.0 39-90 16.55 28.28 50 16 20 18 20 I 15.2 17.2 16. 20 40. CO 28. 10 60 247 58 30 17 so E 39-8 40.4 40. 10 70 39 40 18 so 80 21 40 18 00 70 39 50 18 10 60 58 40 18 50 50 248 17 00 18 20 40 35 00 18 00 30 S3 10 18 10 20 249 II 40 18 30 10 30 00 18 20 47 40 17 40 Value of one division of scale = i'.82. Scale reading of axis 28.29 39-55 Mean scale reading of east ai id west magnetic elongation . . . / 20.49 158 37-48 = difference = II. 26 ions . Azimuth circle reads .... Magnetic meridian reads . At beginning of a. m. observat / // A 54 58 20 158 57-97 B 234 58 40 At end of p. m. observations . A 54 59 20 Mean reading of mark . 144 59- 00 B 234 59 40 = 144 59 00 Azimuth of mark, W. of N. 7 00. 12 True meridian reads . . 151 59.12 M ignetic declina tion 6 58. 85 E. Magnetic observations. 155 Observations for declination mnrle Line of detorsion aoo°. at Salina Cruz, Mexico, March 22, 18S9, by Ensign J. H. L. Ilolcombe, with Kew theodolite mapnelonieler, No S4 with long magnet suspended erect. Local time. a.m. h. m. 9 25 40 10 10 25 40 p. m. Scale reading. Left. d. 40. o 40.8 40.9 41. I 41. I 41. I Right. 40. 2 41. o 41. I 41.4 41.2 41. I Mean. d. 40. 10 40. 90 41. 00 41. 25 41. IS 41. 10 Line of detorsion, ig6 o / // Azimuth circle, A 248 33 00 B 68 34 00 Remarks : At 9:10, suspended torsion weight. At 9:20, suspended magnet. Suspended torsion weight. 12 00 40.8 41- 5 41- IS 30 41. I 41.3 41. 20 45 41.2 41. 6 41.40 I 00 415 41.7 41. 60 JS 41.4 41. 6 41.50 30 41-3 41-5 41.40 45 41. 6 41.8 41.70 2 00 41.7 41.9 41. 80 15 41.9 42. 41- 95 30 42. 42. I 42.05 o / // Azimuth circle, A 248 33 00 1! 68 34 00 Remarks : Suspended magnet at 11:50. Determination of scale value of magnet. Scale. IJeterr Scale in nination of axis of magnet. Scale. Circle read- ings, mean of verniers. Value of 10 divi- sions. read- Mean. Alter nate mean Axis. / // d 249 50 10 E 40. 40. 40. 00 10 32 10 18 00 I 15.0 15.8 15.40 40.25 27.83 20 13 40 18 30 E 40. 41. 40. so 15-25 27-37 3° 248 55 40 18 00 I 15.0 15,2 15. 10 40. 40 27-75 40 46 10 18 30 E 40. 40. 6 40.30 15. 00 27.65 50 18 50 17 20 I 14.8 15.0 14.90 40. 00 27-45 60 00 30 18 20 E 39- 2 40. 2 39-70 70 247 42 20 18 10 80 24 20 18 00 70 42 20 18 00 60 248 00 20 18 00 50 iS 50 18 30 40 46 50 18 00 30 55 20 18 30 20 249 13 30 18 10 10 31 50 18 20 50 00 18 10 Value of one division of | scale ^ i'. S15. Seal e reading of axis 27. 61 41.07 Mean scale reading of, east and west Reduction to axis . magnetic elongation . 24. 42 ^= difierence^ 13-46 Azimuth circle reads . . . Magnetic meridian reads . At beginning of 5. m. observations . 158 33- 50 / // A 54 58 20 158 57-92 B 234 58 20 At end of p. m. observations . A 54 57 40 Mean reading of mark 144 58. 17 7 00. 12 B 234 58 20 = 144 58 10 Azimuth of mark W. of N . . . True meridian reads 151 58.29 Ma jnetic dcclina ion 6 59- 63 E. 156 MAGNETIC OBSERVATIONS. Observations for declination made Line of detorsion, 246^. at Salina Cruz, Mexico, March 23, 1889, by Ensign J. H. L. Ilolcombe, witli Kew theodolite magnetometer No. 54, with long magnet .suspended erect. Local time. h. !/!. 9 40 55 10 10 25 40 55 11 10 25 40 p. m. 12 20 35 40 1 OS 20 35 50 2 05 20 35 50 3 05 20 35 50 Scale readings. Left. Right. d. 39-8 40. 2 40. 2 40. 6 40.8 40.9 41. 41.0 40.9 41. 41. 41.0 41. 41. 41. 41.2 41.2 41-5 Mean. 40. 00 40.40 40.85 41. 00 40.95 41. 00 41. 00 41. 10 41-35 Line of detorsion, 246 41.4 41. 6 41. 41. 6 41.8 41. 41.7 41.8 41. 41-5 41. 6 41. 41-5 41.6 41. 41.8 41.9 41. 41.8 41.9 41. 42.0 42. 42 42. 42. 42 42. 42. I 42 42. 2 42.4 42. 42. 6 42.9 42. 42.9 43-0 42 42.9 43- 42 43-0 43-0 43 .50 .70 -75 •55 •55 .85 .85 . 00 .00 .05 .30 •75 •95 •95 .00 Azimuth circle, A 24S 34 20 B 68 35 20 Remarks : Suspended torsion weight at 9:10. Suspended magnet at 9:30. Azimuth circle, A 24S 34 20 B 68 35 20 -Remarks: Observations continuous; magnet not dismounted. Determination of scale value of magnet. Determination of axis of magnet. Scale. Circle read- ings, mean of Value of 10 divi- Scale. Scale read- Mean. Alter- nate Axis. verniers. sions. mean. / // d. 249 52 10 E 40.0 40. I 40.05 10 34 20 17 50 I 15.0 15- I 15.05 39-70 27^38 20 IS 50 18 30 E 38.9 39-8 39-35 15^ SO 27.42 30 248 57 20 18 30 I IS- 9 16.0 IS- 95 39- IS 27-55 40 3,9 30 17 50 E 38-9 39-0 38-95 1595 27^45 SO 21 20 18 10 I 15.9 16. u '5-95 39^42 27.68 60 02 50 18 30 E 39-8 40. 39-90 70 247 44 20 18 30 80 26 20 18 00 70 44 30 i8 10 60 248 02 30 18 00 50 21 00 18 30 40 39 30 18 30 30 57 20 17 50 20 15 3° 18 10 10 34 20 18 50 249 51 20 17 00 i Value of one division of scale ^ i'.82. Scale reading o( ax is 27 so 41 so Mean scale reading of east an Reduction to axis . Azimuth circle reads . . Magnetic meridian reads . At beginning of a. m. cbsen'a d west magnetic elongation .... ions . / 25. 49 158 34-83 = difference = 14 00 / // A 54 57 20 159 00.32 B 234 58 00 At end of p. m. observations A 54 58 20 Mean reading of mark . . . 144 57-95 B 234 58 00 = 144 57 55 Azimuth of mark W. of N. 7 00. 12 True meridian reads . . * 151 58.03 M agnetic declina tion 7 02. 29 E. MAGNETIC OBSERVATIONS. 157 Observaiions for Jeclinatioii made at Salina Cruz, Me-xicu, March 24, 1889, by [.icut. Cliarle-^ Laird, with Kuw theodolite magnetometer No. 54, with long magnet suspended erect. - Line of detorsion, 260°. Local Scale time. read ngs. Right. Mean. a.m. Left. h. til. ,/. ./. d. 9 25 39-5 40. 39-75 40 40.0 40. I 40.05 55 40.1 40.3 40. 20 10 10 40. s 40.7 40. 60 25 40.8 40.9 40.8s 40 41. 41. 41.00 55 41.0 41. 41. 00 11 10 41.0 41. I 41.05 25 41. I 41.2 41. IS 40 41.8 42.0 41.90 55 42.0 42. 42. 00 . m. Line of detorsion 12 10 42.0 42. I 42.05 25 42.1 42-3 42. 20 40 42.2 42.4 42.30 50 42.4 42.5 42.45 I 10 42.5 42.7 42. 60 25 42.5 42. 6 42.55 40 42-5 42.7 42. 60 55 42.5 42.7 42. 60 2 10 42.7 42.9 42.80 25 42.8 42.9 42.85 40 42.9 43- 42.95 55 43- 43- 43.00 3 10 43-1 43-4 43.25 25 43-1 43-2 43-15 40 43- 43-1 43.05 Azimuth circle, A 24S ji 40 1! 68 32 20 Remarks : Suspended torsion weight at 9, mag- net at 9:10. Clear pleasant weather, northerly wind. Azimuth circle, A 248 31 40 13 68 32 20 Remarks: Observations continuous, azimuth circle same, line of detorsion same as in a. m. observations. Determination ofscale value of magnet. Delcnnination of axis of magnet. Circle read- Value of , 1 Alter- Scale. ings.meanof 10 divi- Scale. Mean. nate Axis. verniers. sions. mgs. mean. / // ,/. 249 50 10 E 40. 40. I 40.05 10 32 20 17 50 I 15- 5 16. 15-75 40. 02 27.88 20 14 00 18 20 E 40. 40.0 40. 00 15-95 27 97 30 248 56 00 18 00 I 16. 16,3 16. 15 39-95 28.05 40 37 40 18 20 E 40. 39-8 39-90 16.37 28.03 50 19 20 18 20 I 16. 4 16.8 16. 60 39-97 28.28 60 I 00 18 20 E 40. 40. I 40.05 70 247 42 3° 18 30 80 24 40 17 50 70 42 50 18 10 60 01 10 18 20 50 19 20 18 10 40 37 50 18 30 30 56 10 18 20 20 14 20 18 10 10 32 30 18 10 50 20 ' 17 50 Value uf one division of scale = i'.82. Scale reading uf ax is 28.06 41.40 Mean scale reading of east ai d west magnetic elongation . . Reduction to axis . 24. 28 158 32. 00 ^ difference = 13-34 tiuns . Azimuth circle reads Magnetic meridian reads . At beginning of a. m. observa / // A 54 57 00 158 56.28 . . B 234 57 20 At end of p. m. observations Mean reading of mark . A 54 58 20 1; 234 58 20 144 57-75 = 144 57 45 Azimuth of mark \\'. of N. 7 00. 12 1 True meridian reads . . . 151 58.87 M igiietic declina tion 6 58.41 E. 158 MAGNETIC OBSEIiVATIONS. Observations for dip made at Salina Cruz, Mexico, March 17 and 18, 1889, by Ensign ]. H. L. Ilolcombe, with dip circle No. 84 and needle No. I. IMean by polarities.] [Mean by polarities.] Polarity of marked end north. Circle east. Circle west. Pace east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / / / 39 47 39 46 40 10 39 58 3958 40 04 40 12 40 12 SI 50 08 55 40 00 07 17 17 49 48 09 56.5 39 59 05. s 145 14.5 39° 48'.5 40° 02'. 7 40° 02^.2 40° H'-S 39° 55'.6 40° 08'. 3 Mean, 40° 01'. 45 Polarity of marked end south. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N. / / / / / / / / 40 01 40 10 40 01 40 02 39 43 39 40 40 13 40 00 05 t3 10 13 45 41 13 39 59 03 11.5 05-5 07.S 44 40.5 13 S9-S 40° o^'.2 40° 06'. 5 39° 42'.3 40° 06'. 2 40° o6'.8 39° 54'-2 Mean, 40° o'.S Resulting dip, 40° C/.97. March 17, 1889. Circle in Mag. prime vertical. Local time of beginning, 2: 15. Local time ol ending, 2:40. / Circle N. Needle N. 48 20 " S. 47 SI Circle S. " N. 48 07 S. 48 36 Mean, 48 13-5 Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. f / / / / / / / 4004 3950 39 40 39 38 40 28 4029 3958 40 09 02 48 37 35 28 29 58 09 03 49 38.S 36.5 28 29 58 09 39° S6' 39° 37'-5 40° 28'.5 40° o3'.5 39° 46'.7 1 40° 16' Mean, 40° oi'.3 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. F'ace east. S. N. S. N. S. N. S. N. / / / / / / / / 40 22 40 22 39 45 39 54 40 04 3952 39 39 39 38 20 20 49 58 10 56 41 40 21 21 47 56 07 54 40 39 40° 21' 39° 5i'-5 40° 00'. 5 39° 39'-S 40° 06'. 3 39° 50' Mean, 39° 58'.! Resulting dip, 39° 59'. 7 March 18, 1889. Circle in Mag. prime vertical. Local time of beginning, 1:30 Local time of ending, 2:30 / Circle N. Needle N. 48 23 " S. 47 46 Circle S. " N. 48 00 '■' S. 48 43 Mean, 48 13 MAGNJiTlC OBSEEVATIONS. 159 Observations for horizontal intensity by the method of dedections with Kuvv theodolite magnetometer No. 54, at Salina Cruz, Mexico, March iH and 19, 1889, by Ensign J. H. L. Ilolcomlje, long magnet deflecting al right angles to short magnet suspended. Distance r = o'". 355- Distance r - = 0" 325- ._; Circle readings. Circle readings. c Circle readings. Circle readings. a; 0) bO 1 No. A. B. Mean. No. A. B. Mean. Nu. A. B. Mean. No. A. B. Mean. E. W. I / // 76 30 00 / // 2940 / // 2950 2 / // 65 28 00 / // 2800 / // 28 00 E. W. I / // 78 17 40 / // 1740 r // 1740 2 / // 63 55 20 / // 5540 5530 ^ E. 3 29 40 29 20 2930 ^ E. 3 17 40 1740 17 40 rt W. 4 28 20 2820 28 20 W. 4 55 00 5500 5500 E. 5 30 20 30 20 30 20 E. 5 17 00 17 00 17 00 Mean, 76° 29' 53" 65° 28' 10" Mean, 78° i 7' 2 7" 63° 55' 15" W. 6 65 23 40 23 40 2340 W. 6 63 47 20 4740 47 30 E. 7 76 20 40 20 40 20 40 E. 7 78 04 20 04 40 430 W. 8 23 20 2340 23 30 W. 8 47 00 4700 4700 1) E. 9 20 40 20 20 20 30 E. 9 41 20 41 20 41 20 W. 10 08 00 08 20 08 10 .Me: m, 73° 41' 20" 68° 08' 10" Computation : — ^|?^sin«(i ) H r- / Magnet east, 2 m =i 5 34. 78 Sin u P ^-^ temp., etc. Logarithms. Magnet west, 2 i( = 5 33. 17 Mean, 5 33.97 a = 2 46. 98 Time of beginning, 4:30 p. m. Time of ending, 5:00 Temp., 29. Temp., 27. 5 8. 64367 8.68621 9. 99905 0. 00475 » lean, 4:45 /■=28 2 m H 7- 33367 Distance r — o'".4is. E. W. E. W. E. Circle readings. No, o / // 74 27 00 27 20 27 00 B. / // 27 00 27 00 27 00 Mean. / // 27 10 27 10 27 00 Circle readings. No. o / // 67 34 00 34 00 3400 3400 Mean. 3400 3400 Mean, 74° 27' 03' 67° 34' 00' W. E. W. E. W. 74 22 40 23 00 23 00 23 00 22 50 2300 ^7 31 20 31 40 32 00 31 20 31 40 32 00 31 20 3' 40 32 00 Mean, 74° 22' ss'' 67° 31' 40" Computation : — = ^ ;-' sin « ( I . H r' Magnet east, 2 a ^ 6 53. 05 Magnet west, 2 « ^ 6 5 J . 25 Mean, 6 52. 15 « = 3 26. 07 Time of beginning, 3:05 p. m. Time of ending, 3:37 Mean, 3:21 Temp., 31. 2 Temp., 29. 8 / = 30. 5 Sin u P I — — temp., etc. m H Logarithms. 8.55161 8. 77747 0.00173 0.00516 7- 33597 21124_No. 97 11 162 MAGNETIC OBSERVATIONS. Observations of vibrations, made at Salina Cruz, Mexico, March 19, 1889, by Ensign J. H. L. Holcombe. Chro. error, Daily rate + j,'.iij. Civil time, a. m. Temp, of magnet. Hor. foice magnetometer. Hor . force thermometer. At commencement . h. S m. 48 32.0 C. At end . ... Means Corrected means . 6 •25 31.8 31.9 31.6 Scale moving apparently — To the right. To the left. No.' of Vib. Time of passing wire. Time of l8oVib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scale divi- sions. Means and differ- ences. h. m. s. m, s. h. m. s. m. s. c \\ 29 7.0 9 II 29 37.0 40.00 180 39 7-6 10 0.6 189 39 37.6 10 0.6 + 90 41-55 18 30 6.8 27 30 37- 40.00 For 90° 198 40 7.4 10 0. 6 207 40 37. 6 10 0. 6 — 90 38.00 36 31 6.7 45 31 36.8 40.00 216 41 7.6 10 0. 9 225 41 37-6 lo 0.8 +360 47.50 Bor 360° 54 32 6.7 63 32 36. 6 39.60 For 90° 234 42 7.7 10 I. 243 42 37- 5 10 0. 9 — 360 32.50 Adopted effect go° 72 252 90 270 336.6 43 7.6 34 6.6 44 7.6 10 I.O 10 1.0 81 261 99 279 33 36. 6 43 37. 7 34 36. 6 44 37-8 10 I. I 10 I. 2 40.50 Torsion! .88 Sc.Div. 1 + ji=i.ooo63 I Sc. Div.= i'.8 90 99 9 Vertical scale, 25 Time for i8oth. Time for 189th. Mean . 10 0.85 Time, 90 Vib. 10 0. 87 Meantiir e — iSoVib's 6oo».86 Time, I Vib. = T„ = 3''.338 MAGNETIO OBSERVATIONS. 163 Time azimuths taken at Port Plata, San Domingo, December 28, 1889, by Ensign L. M. Garrett, with theodolite ; chronometer 1596, 11- .z'.^i slow on G. M. T. jy > 3 3 Before. After. / // / // Reading of mark, A 326 05 00 326 05 30 B 146 04 30 146 05 00 Chronometer time, p. m. Reading of circle. Telescope. Remarks. A. B. A. m. 5. / // / // 8 29 07 345 OS 30 165 05 30 Direct. 31 17- S 345 23 00 165 23 00 Direct. 36 SO 344 07 30 164 07 c» Direct. 38 58 344 26 00 164 25 30 Direct. 8 49 44 162 32 30 342 32 30 Inverted. 52 20.5 162 48 00 342 47 30 Inverted. SS "0 161 54 00 341 54 00 Inverted. Before, After. / // / // Reading of mark, A 146 02 30 146 02 30 B 326 02 30 326 02 30 Latitude, 19° 49' 29" N. Longitude, 4'' 42™ 47S.6 W. Solution by: Tan X = sin D cosec S cot i ^") S = i [/ + (90° — 9)] Tan Y = cos D sec S cot ^ ^ ^ D = i [/ — (90° — 9))] Az. — X -t Y J 164 MAGNETIC OBSEKVATIONS. Observations for declination made at Port Plata, San Domingo, December 25, 1889, by Ensign L. M. Garrett, with Kew theodolite magnetometer No. 54, with long magnet suspended. Line of detorsion, 20°. Local time. 8 15 30 45 9 00 IS 30 45 10 00 15 30 p. m. 12 30 45 1 00 15 30 45 2 00 IS 30 45 3 00 IS 30 Scale readings. Left. Right. d. ,1. 33-6 46.6 38.4 41.8 39-3 41.5 39-8 40.8 40.3 40.8 40.2 40.9 40. 2 40.5 39-6 40. S 39-6 39-9 Mean. d. 39. 80 40. 10 40. 10 40.40 4Q. 30 40-SS 40.55 40-3S 40. 20 39-75 Azimuth circle, A 33 22 20 B 22 40- Line of detorsion, 45 36.1 39- 36.8 37-8 37-2 37-7 37-3 37-7 36.2 38.4 36.8 38.0 35-8 38.0 36.8 37.6 37- 37-2 37-0 37-2 37-2 37-2 37-2 37-7 37-3 37-9 37.60 37-30 37-40 37-50 37-30 37-40 36.90 37.20 37- 10 37-10 37.20 37-40 37.60 Remarks ; Removed torsion and suspended magnet at 8:00. Azimuth circle, A 33 22 20 B 22 40 Remarks : Replaced magnet at I2;20: moved torsion head to 45°. Determined axis and scale value. Determination of scale value of magnet. Determination of axis of magnet. .Scale. Circle read- ings, mean of verniers. Value of 10 divi sions. Scale. Scale read- ings. Mean. Alter- nate mean. Axis. / // / // d. 34 30 40 E 37-3 37-7 37-50 10 12 40 18 00 I 18.2 15.0 16. 60 37-40 27.00 20 11 54 50 17 50 E 36.2 38-4 37-30 16.62 26. 96 30 36 50 18 00 I 19-7 13-6 16.65 37-35 27.00 40 18 40 18 10 E 36.8 38.0 37-40 16.65 27.02 50 20 18 20 I 19-3 14. 16. 6S 37.22 26.94 60 32 42 10 18 10 E 36.1 38.0 37-05 70 24 10 18 00 80 6 00 18 10 70 24 00 18 00 60 42 10 18 10 50 33 00 20 18 10 40 18 20 18 00 30 36 30 18 10 20 54 30 18 00 10 34 12 40 18 10 30 40 18 00 Value of one division of scale = I '.808. Seal e reading of axis ... 26.98 38.83 Mean scale reading of east ar id west magnetic elongation . . . Reduction to axis . 21. 25 33 22. 30 = difl'erence = 11.85 / // A 108 22 40 B 22 20 tions . Magnetic meridian reads . At beginning of a. m. observa 33 43- 55 At end of p. m. observations Mean reading of mark . A 22 00 B 21 40 108 22. 10 = 108 22 10 ofW. . 75 15-21 33 06. 49 True meridian read s . . . . tion . . • • ■ Me ignetic declina 37. 06 E. MAGNETIC OBSERVATIONS. 165 Observations for declination Line of detorsion 20°. made at Port Plata, San Domingo, December 26, 1889, by Ensign L. M. Garrett, with Kew theodolite magnetometer No. 54, with long magnet suspended erect. Local time. a.m. h. til. 9 15 30 4S ID GO 15 30 45 II 00 p.m. 2 00 15 3° 45 3 00 15 30 Scale reading. Left. Right. 40. I 40-5 40-5 40. 6 40.6 40.4 40. 2 d. 40.7 40.7 40.7 40.6 40. 6 40-5 40-3 Mean. d. 40. 40. 40. 40. 40. 40. 40- Line of detorsion 20 35-8 35-8 36.1 36.2 36.1 36.5 36.8 37-8 37-2 36.8 36.5 36.9 36.7 36.8 o / // Azimuth circle, A 33 22 00 B 22 00 Remarks : Removed torsion weight and sus- pended magnet at 9:00 a. m. After last reading, suspended tor- sion weight. Azimuth circle, A 33 22 00 B 22 00 Remarks : Removed weight and suspended magnet at 1:55 p. m. Observed for scale value and axis after last reading. Determination of scale value of magnet. Determination of axis of magnet. Scale. Scale read- ings, mean of Value of 10 divi- Scale. Scale read- ings. Mean. Alter- nate Axis. verniers. sions. mean. / // / 1/ d 34 29 30 E 36.8 36.8 36.80 10 II 20 18 10 I 19-3 IS- 7 17,50 36.85 27.15 20 33 53 10 18 10 E 34- 39-8 36.90 17-45 27.15 30 35 10 18 00 I 20. 2 14. 6 17.40 36.85 27-15 40 16 50 18 20 E 35-6 38.0 36.80 17.40 27.12 5° 32 58 30 18 20 I 18.9 15-9 17.40 36.85 27-13 60 40 00 18 30 E 36. 37-8 36.90 70 22 20 17 40 80 04 00 18 20 70 22 10 18 10 60 40 10 18 00 SO 58 50 18 40 40 33 17 10 18 20 30 35 40 18 30 20 53 50 18 10 10 34 12 00 18 10 30 00 18 00 Value of one division of scaler I '.822. Scale reading of a> is .... 27.14 38-47 Mean scale reading of east ai Reduction to axis id west magnetic elongation / 20. 63 = difference ^ 11-33 Azimuth circle reads .... Magnetic meridian reads . At beginning of a. m. observa tions . 33 22. 00 / // A 108 23 00 33 42- 38 B 22 40 At end of p. m. observations A 21 20 Mean reading of mark . . . 108 22 00 B 21.00 = 108 22 00 Azimuth of mark S. of W . 75 15 21 True meridian reads . . . . 33 06 39 E. tion . . . 1.^ IJQ „^...,.. 1 166 MAGNETIC OBSERVATIONS. Observations for dip made at Port Plata, San Domingo, December 19 and 21, 1889, by Lieut. Charles Laird, with dip circle No. 84, and needlt A i. [Mean by polarities.] [Mean by polarities.] Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / f / 49 58 49 37 49 35 4926 50 21 50 27 49 50 SO 07 58 36 36 26 II 18 48 05 58 36-5 35-5 26 16 22.5 49 06 49° 47'-2 49° 3o'-7' 50° I9'.2 49° 57'-5 49° 39' 1 50° o8'.3 Mean, 49° 53''.6 Polaiity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. .S. N. / / / / r / / / 50 21 50 22 49 34 49 52 49 59 49 37 49 29 49 20 16 17 37 54 57 35 27 18 18.S 19s 35-5 S3 58 36 28 '9 50° 19' 49° 44'-2 49° 47' 49° 23'.5 50° oi'.6 49° 35'-2 Mean, 49° 48'.4 Resulting dip, 49° Sl'.o. December 19, 1889. Circle in Mag. prime vertical. Local time of beginning, 9:30 a. m. Local time of ending, 1 1 130 a. m. / Circle N. Needle N. 90 30 Magnetic meridian reads 90° 22' " S. 10 Circles. " N. 15 " s. 35 Mean, 90 22. 5 Polarity of marked end south. Circle east. Ciftle west. Face east. Face west. Face east. Face west. •S. N. S. N. s. ■ N. S. N. / / / / / / / / SO 04 49 41 4929 49 20 50 19 5023 49 41 49 58 05 43 29 : 20 20 25 44 50 01 04-5 42 29 j 20 «9-5 24 42.5 49 59-5 49° 53'-2 49° 24'-5 50° 21'. 7 49° 5"' 49' 38'.8 50° o6'.3 Mean, 49° S2''.6 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N. / / / / / / / / 49 53 50 II SO 09 50 12 49 57 4929 49 35 49 25 49 06 09 13 54 29 35 25 5' 08.5 09 12,5 55-5 29 35 25 49° 59'-7 50° 10^.7 49° 42^.2 49° 30' 50° OS'.2 49° 36'.! Mean, 49° y>^ A Resulting dip, 49° si'-6. December 21, 1889. Circle in Mag. prime vertical. Local time of beginning, 2:30 p. m. Local time of ending, 4:00 p. m. / Circle N. Needle N. 90 15 Magnetic meridian reads 90° 06' " S. 89 25 Circle S. " N. 90 54 " S. 89 51 Mean, 90 06 MAGNETIC OBSERVATIONS. 167 Observations for dip made at Port Plata, San Domingo, December 20 and 25, 1889, by Lieut. Charles Laird, with dip circle No. 84 and needles A 2 and A 1 [Mean by polariUes.] [Mean by polarities.] Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / / / 4929 49 H 50 04 49 40 49 50 50 01 5038 SO 43 29 14 °3 39 48 49 59 33 38 29 u 03-5 395 49 50.00 35-5 40.5 49° 21'. 5 49 51'- 5 49° 54'- 5 50° 38'.o 49° 36'.S 50° l6'.2 Mean, 49° 56''.3 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N, / / / / / / / / 49 37 49 49 50 21 50 28 49 27 49 15 49 26 49 IS 39 50 23 29 28 14 27 14 38 49-5 22 28.5 27.5 14.5 26.5 14-5 49° 43'- 7 50° 25'.2 49° 21' 49° 2o'.5 50° o4'.4 49° 20'. 7 Mean, 49° 42^.5 Resulting dip, 49° 49' .4 December 20, i88g. Circle in Mag. prime vertical. Local time of beginning, 2: 10 p. m. Local time of ending, 4: 10 p. m. / Circle N. Needle N. 29 36 Magnetic meridian reads 30° 20' " S. 32 35 Circle N. " N. 28 23 S, 30 46 Mean, 30 20 Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. 1 S. N. S. N. S N. S. N. / / / / / / / / 49 52 4946 49 20 49 24 50 22 50 11 •49 43 49 44 55 SO 23 25 24 12 42 44 53-5 48 21-5 24-S 23 "•5 42-5 44 49° 5o'.7 49° 23' 50° 17'. 2 49° 43'-2 49° 36'.8 50° O0'.2 Mean, 49° 48^.5 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N. / / / / / / / / 50 18 5007 49 SI 49 51 49 51 49 46 49 23 49 25 20 09 52 51 52 47 22 24 19 08 51S SI 515 46.5 22.5 24-5 i 50° i3'-5 49° 5"'-2 49° 49' 49° 23'.S 50° 02'. 3 49° 36'. 2 Mean, 49° 49'. 2 Resulting dip, 49° 48'.8 December 25, 1889. Circle in Mag. prime vertical. Local time of beginning, 9:45 a. m. Local time of ending, 10:45 a. m. Magnetic meridian reads 30° 1 2' / Circle N. Needle N. 30 23 " S. 29 52 Circle S. " N. 30 32 S. 30 01 Mean, 30 12 168 MAGNETIC OBSEliVATIONS. Observations for dip made at Port Plata, San Domingo, December 23 and 25, 1S89, by Ensign L. M. Garrett, with dip circle No. 84 and needle No. Al. [Mean by polarities.] [Mean by polarities.] Polarity of marked end north. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / / / 49 26 49 30 49 47 49 38 39 55 49 54 50 16 50 04 25 30 47 38 57 55 15 03 25-5 30 47 38 56 54-5 15-5 03-5 49° 27'.7 49° 24'-5 49° 55'-2 50° o9'.s 49° 35'- 1 50° 02'.3 Mean, 49° 48^.7 Polarity of marked end south. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. ,S. N. S. N. S. N. / / / / / / / / \9 53 •49 52 50 34 50 23 49 >9 49 22 49 53 49 45 52 53 35 22 18 23 54 47 52-5 52.5 34-5 22.5 18.S 22.5 53-5 46 49° 52'.5 50° 28^.5 49° 20^.5 49° 49'- 7 50° io'.5 49° 35'- 1 Mean, 49° 52^.8 Resulting dip, 49° 50^.7. December 23, 1889.. Circle in Mag. prime vertical. Local time of beginning, 1:45 p. m. Local time of ending, 3:45 p. m. / Circle N. Needle N. 59 27 S. 60 II Circle S. " N. 60 06 Magnetic meridian reads 60° 08'. " S. 60 47 Mean, 60 08 Polarity of marked end north. Circle east. Face east. 49 24 23 23-5 N. 49 26 27 26.5 49° 25' Face west. S. 4948 50 49 N. 49 43 43 43 49° 46' 49° 35'-5 Circle west. Face east. 49 54 55 54-5 N. 49 S3 54 53-5 49° 54' Face west. 5023 23 23 N. 50 II "•5 50° 17' 50° 05 '.5 Mean, 49° 5o'.5 Polarity of marked end south. Circle west. Face west. 49 47 46 46.5 N. 49 46 46 46 Face east. 5030 32 N. 50 19 21 20 49° 46'.2 50° 2S'.5 50° oS'.8 Circle east. Face west. IS 14 16 N. o / 49 18 19 18.5 Face east. S. 50 00 00 N. 49 52 54 53 49° i7'-2 49° S6'.S 49° 36'.8 Mean, 19° 5i'.3 Resulting dip, 49° So'.9. December 25, 1889. Local time of begin'g, 12:35 P- ""■ Local time of ending, i:5op. m. Mag. meridian reads 30° 09'. 5. Circle in Mag. prime vertical. o / Circle N. Needle N. 69 22 " S. 30 22 Circle S. " N. 30 01 " S. 30 S3 Mean, 30 09 MAGNETIC OBSERVATIONS. 169 Observation for horizontal intensity by the method of deflections with Kew theodolite magnetometer No. 54, at Port Plata, San Domingo, December 19 1889 by iinsign L. M. Garrett, with long magnet deflecting at right ancles to short magnet, susnended. Distance r= o™,3oo. ong magnet deflecting at right angles to short magnet, suspended. Distance r= o"'.2oo. -a a Circle readings. Circle readings. 1 it No. A, B. Mean, No. A. B. Mean. f // / // / // / // / // / // E. I 1S3 31 20 3' 40 31 30 "\V. 2 163 21 00 21 20 21 10 ^ E. 3 31 20 31 40 31 30 rt Ui W. 4 21 00 21 20 21 10 E. S 30 20 3040 3030 Mean, 183° 31' lo" 163° 21' 10" W. 6 163 13 40 14 20 14 00 E. 7 183 14 20 1440 1430 _; W. 8 1340 14 20 14 00 1) E. 9 14 20 1440 1430 W. 10 14 20 15 00 1440 Mean, 183° 14' 30" 163° 14' 13" m P Computation: — ^Jr'sin«(l — — ) / Magnet east, 2 a ^ 20 10. 00 Magnet west, 2 » = 20 00. 1 7 i>^ Logarithms. 8. 13072 Mean, 20 05. 08 Sin « 9.24141 a^ 10 02.34 P 9. 99697 Time of beginning, 9:25 a.m. Time of ending, 10:20 a.m. Temp., 28. C. Temp., 29. temp., etc. 0. 00490 Mean, 9:52 ^■=28. 5 m H 7. 37400 W ^ S a .a Circle readings. Circle readings. No. A. B. Mean. No. A. B. Mean. / // / // / // / // / // / // E. I 210 37 20 37 20 37 20 W. 2 137 18 20 18 20 18 20 E. 3 40 00 40 20 40 10 W W. E. 5 41 00 40 40 5040 4 16 40 17 00 1650 Mean, 210° 39' 27" 137° 17/ 35" W. 6 136 33 40 3340 3340 E. 7 208 50 20 5040 5030 W. 8 31 00 31 00 31 00 0) E. W. 9 5040 5040 5040 10 29 00 29 00 29 00 Mean, 208° 50' 35" 136° 31' 13" Computation : m . P -=ir'sm«(i--^ ) Magnet east, 2 « = Magnet west, 2n = Mean, u — / = 7321.52 = 72 19. 22 72 50. 37 = 3625 18 4^ Sin u p Logarithms. 7. 60225 9. 77358 I— — ,,■2 9.99315 Time of beginning. Time of ending, 10:50 a.m. 1 1:40 a.m. Temp., 28. 4 C. Temp., 29. 4 temp., etc. m H 0. 00536 Mean, 11:30 ^=28 9 7. 37434 170 MAGNETIC! OBSERVATIONS. Observation for horizontal intensity by the method of deflections with Kew theodolite magnetometer No. 54, at Port Plata, San Domingo, December 23, 1889, by Ensign L. M. Garrett, with long magnet deflecting at right angles to short magnet, suspended. Distance r:=o'".30o. 13 C Circle readings. Circle readings. •a No. A. B. Mean. No. A. E. Mean. / // / // / // / // / // / // E. I 183 14 00 14 20 14 10 W. 2 163 01 20 I 20 I 20 E. 3 13 20 13 20 13 20 (3 W. 4 01 20 I 00 I 10 E. 5 13 20 13 20 13 20 Mean, 183° 13' 40" 163° 01' 15" W. 6 162 50 00 49 40 49 50 E. 7 182 54 50 55 00 54 55 W. 8 49 20 49 20 49 20 (A E. W. 9 54 20 54 20 54 20 10 49 40 50 CO 49 50 Mean, 182° 54' 37'' 162° 49' 40'° Computation : m — ^ i r» sin u {\ H ^ *■ P ) Magnet east, 2 it - Magnet west, 2 u = Mean, u - / // = 20 12 25 = 20 04 57 20 08 41 = 10 04 20 4^- Sin «< P Logarithms. 8. 13068 9. 24276 Time of beginning , 3:50 p. m. Temp., 25. 2 C. l-r^ 9. 99697 Time of ending, 4:30 p. m. , 4:10 Temp., 25,0 temp., etc. m H 0. 00426 Mean t=2_ ;•« 7- 37467 MAGKETIO OBSERVATIONS. 171 Observations of vibrations, made at Port Plata, San Domingo, December 22, 1889, by Ensign L. M. Garrett. Chro. error, 1 1» 39'.o slow. Daily rate, a'.os losing. Civil time, u. m. Temp, of magnet. Hor. force magnetometer. Hor. force thermometer. At commencement A. m. 10 45 27. s c. At end II 05 27.5 Means 27.5 Corrected means . 27.1 Scale moving apparently — Torsion force. To the right To the left. No. of Vib. Time of passing wire. Time of 180 Vib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scalt sic ; divi- ms. Means and differ- ences. h. m. s. m. s. A. m. s. m. i. 3 17 45- 9 3 i8 17. 39.20 180 28 24. 10 39. 189 28 55- 9 10 38.9 + 90 39-5° 18 18 49. 27 19 21. 39-15 For 90° 198 29 27. 8 10 38. 8 207 29 59. 7 10 38.7 — 90 38.90 36 19 53- 45 20 24. 9 39- °5 216 30 31-6 10 38. 6 225 31 03. 5 10 38.6 +360 39-83 For 360 54 20 56. 8 63 21 28. 7 38.57 For 90° 234 31 35- S 10 38.7 243 32 07. 4 10 38.7 —360 37-55 Adopted effect 90° 72 252 90 22 00. 5 32 39- 3 23 04. 5 10 38. 8 81 261 99 22 32.5 33 I'- 3 23 36-4 10 38. 8 38-56 Tors'no.256Sc.Div. i' = o''.46 I Sc. Div.= I'.S 270 33 43- 3 10 38. 8 279 34 IS- 3 10 38. 9 i+- = i.cxx)09 90 05 19-5 99 5 19-4 Vertical scale, 19.3 Time for 180th. 28 24. 60 232. 7 Time for 189th. 28 55. 8 60 232. 6 Mean ..... 10 38.775 638».77S Time, 90 vib. Time, I vib. 3i9».3875 Mean time — 180 vibs. = T„ = 3'-S497 172 MAGNETIC OBSEKVATIONS, Observations of vibrations, made at Port Plata, San Domingo, December 22, 1889, by Ensign L. M. Garrett. Chro. error, 11" agvs slow. Daily rate, 2".o3 losing. Civil time, p. m. Temp, of magnet. Hor. force magnetometer. Hor. force thermometer. At commencement . h. 3 m. 50 25.8 C. At end Means Correcte 4 30 25.8 25.8 d means . 25-4 Scale moving apparently — To tlie right To the left. No. of Vib. Time of passing wire. Time of 180 Vib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scale divi- sions. Means and differ- ences. //. m. s. 8 24 34. 3 m. s. 9 h. m. s. 8 25 06. 2 m. s. 40.00 180 35 13- I 10 48. 8 189 35 45-1 10 38. 9 + 90 40. 22 18 25 38- 2 27 26 10. 2 40.00 For 90° 198 36 17. 1 10 38. 9 207 36 49. 10 38. 8 — 90 39- 60 36 26 42. 1 45 27 14.0 40. 20 216 37 21.0 10 38. 9 225 37 53- 10 39.0 +360 41- 13 For 360° 54 27 46.0 63 28 18.0 40. 10 For 90° 234 38 24. 9 10 38. 9 243 38 56. 8 10 38.8 — 360 39.10 Adopted effect 90° 72 28 49. 9 81 29 21. 8 0. 40. 20 Tors'no.261 Sc.Div. 252 90 39 28. 7 29 53-7 10 38. 8 261 99 40 00. 7 30 25.6 10 38. 9 F 7 I Sc. Div. = i'.8 270 40 32- 5 to 38. 8 279 41 04.5 10 38. 9 I. 00009 90 05 19.4 60 233. I 9? 9 05 19-4 60 233. 3 Vertical scale, 16.8 Time for 1 80th. 35 13- I 10 38. 8s Time for 189th. 35 45 10 38 88 10 38.865 638».86s Time, 3i9'-432 = T„ = Mean tin ne — 180 vib's. 90 Vib. Time, I Vib. 3'-5492 MAGNETIC OBSEliVATIONS. 173 Time azimuths taken at Curasao, West Indies, January 31, 1890, by Ensign L. M. Garrett, with theodolite and chronometer 1596 13™ o7=.24 slow on G. M. T. Before. After. o / // o / // Reading of mark, A 286 18 00 286 17 30 B 106 17 30 106 17 30 Chronometer time, p. m. //. m. s. 8 27 25.5 28 42. S 29 48.5 30 49.0 31 390 Reading of circle. A. (3 o / // 344 46 30 344 38 30 Q 344 31 00 a 344 24 00 ca 344 20 00 o / // 164 46 00 164 38 00 164 31 00 164 24 30 164 19 30 Telescope. Remarks. Latitude, 12° 06' 45" N. Longitude, 4" 35" 48=.: W. Solution by : Tan X = sin D cosec S cot i /I S = i [/+(90°— ?>)] Tan Y = cos D sec S cot i A D = i [i>— (90°=?')] Az = X -t Y J 174 MAGNETIC OBSERVATIONS. Observations for declination made at Curasao, West Indies, January 28, 18 magnet, Line of detorsion, 90**. JO, by Ensign L. M. Garrett, with Kew theodolite magnetometer No. 54, with long suspended erect. Local time. Scale readings. Mean. / // Azimuth circle, A 60 40 00 B 39 40 Determination of scale value of magnet. Determination of axis of magnet. u. m. Left. Right. Scale. Circle read- ings, mean of verniers. Value of 10 divi- sions. ■ Scale. Scale read- ings. Mean. Alter- nate mean. Axis. h. m. 9 00 15 30 45 ID 00 "5 30 45 11 00 d. 39- 39- I 39-6 39-6 39-4 39-7 38.8 39-5 39-7 d. 40.0 39-7 39-6 40. 40.0 39-9 40. 6 40. 39-9 d. 39-5 39-4 39-6 39-8 39.7 39-8 39-7 39-7 39-8 Remarks : Removed torsion weight and sus- pended magnet at 8:45. Removed magnet and suspended weight. 10 20 30 40 50 60 70 80 70 60 SO 40 30 20 10 / // 61 47 30 29 lO II 00 60 52 50 34 40 16 20 59 58 10 39 40 21 20 39 30 58 00 60 16 10 34 40 52 35 61 10 50 29 10 47 10 18 20 18 10 18 10 18 10 18 20 18 ID 18 30 18 20 E I E I E I E 37-2 15.6 37- 16.6 37-1 16. 1 36.7 37-8 17.8 38.1 17.0 37-7 17-5 38.0 37.50 16.70 37-55 16.80 37- 40 16.80 37-35 37-52 16-75 37-47 16.80 37-37 16.75 37-42 d. 27- '3 27. II 27-13 27.08 27.06 27.08 p.m. Line of deters ion, 90. / // Azimuth circle, A 60 40 00 B 39 40 12 30 45 1 00 15 30 45 2 00 15 30 45 38.3 38.3 38.0 38.0 37-8 37-8 37-8 37.8 37-8 37.8 39.2 38.8 39.0 38.2 38.3 38.0 37.8 37.8 37-8 37. s 38.70 38.50 38.50 38.10 38.05 37-9° 37.80 37.80 37.80 37.80 Remarks : Removed weight and suspended magnet at 12:15 P- ■"• No torsion. Determined scale value and axis. Value of one division of scale = I '.826. Scale reading of ax is 27. 10 38.80 Mean scale reading of east and west magnetic elongation Reduction to axis . Azimuth circle reac / 21.34 60 39. 83 = difference = II. 70 Is / // A 181 09 20 B 09 20 A 09 40 B 09 40 Magnetic meridian reads 61 01. 17 At beginning of a. m. observatic At end of p. m. observations . ns . . 181 09.50 122 37. 16 58 32. 34 Mean reading of m Azimuth of mark \1 True meridian reac Magnetic declina irk — 181 00 70 iT.ofN s 2 28. 83 2° 28' 50" E. MAGNETIC OBSERVATIONS. 175 Observations for declination made at Cura(;ao, West Indies, January 29, 18 magnet Line of detorsion, 70^. 90, by Ensign L. M. Garrett, witli Kew theodolite magnetometer No. 54, with long suspended erect. Local time. a. m. h. m. 9 00 IS 20 45 10 00 15 30 45 55 p. m. 12 30 45 1 00 15 30 45 2 00 Scale readings. Left. Right. d. 39-6 39-8 39-9 40. 1 40. o 40.0 39-9 39.8 39-7 d. 40. 6 40. 2 40- 3 40. 6 40.2 40. 2 40-3 40. o 39-9 Mean. J. 40. 10 40. 00 40. lo 40.35 40. 10 40. 10 40. 10 39-9° 39.80 Line of detorsion 38.7 38.5 38.3 38.1 38.0 37-9 38.0 39- o 38.7 38. 5 38.4 38.2 38.1 38.2 38.8s 38.60 38.40 38.25 38.10 38.00 38.10 Azimuth circle, A 60 38 00 B 37 40 Remarks : Removed torsion and suspended magnet at 8:50 a. m. ? Probable disturbance. Removed magnet and suspended torsion weight. Azimuth circle, A B o r If 69 38 00 37 40 Remarks : Removed weight and suspended magnet at 12:05. After last reading determined axis and scale value of magnet. Determination of scale value of magnet. Determination of axis of magnet. Circle read- Value of Scale read- ings. Alter- Scale. ings, mean of 10 divi- Scale. Mean. nate Axis. verniers. sions. mean. / // d. 61 47 10 17 50 E 38.0 38.2 38. 10 38.20 27-13 10 29 20 18 20 I 17.2 15.0 16. 10 16.07 27. 12 20 II 00 18 00 E 37.7 38-9 38.30 38.17 27.08 30 60 53 00 I 16.2 15.9 16.05 16. 00 27.05 40 34 30 18 30 18 20 E 38.3 37.8 38.05 38.10 27.06 50 16 10 18 20 I 16. 9 15.0 >5-95 16.02 27.07 60 59 57 50 18 10 E 37-5 38.8 38.15 38.12 70 39 40 18 20 80 21 20 18 30 70 39 50 18 05 60 57 55 18 15 50 60 16 10 18 20 40 34 30 18 15 ^0 52 45 18 05 20 61 10 50 18 20 10 29 10 18 10 47 20 Value of one division of scale= 1^.825. Scale reading of axis 27.085 39.050 Mean scale reading of east and Reduction to axis . west magnetic elonga tion / 21.83 ^= Difference = 11.965 Azimuth circle reads .... Magnetic meridian reads . At beginning of a. m. observati( ms . . 60 37. 83 / // A 181 09 40 60 59. 66 B 09 40 A 09 00 B 09 00 iSi 09. 33 — 181 09 20 122 37, i6 58 32. 17 True meridian reads Magnetic declination 2 27.49 2° 27' 30''' E. 176 MAGNETIC OBSERVATIONS. Observations for dip made at Curasao, West Indies, January 26, 1890, by Lieut. Charles Laird, with dip circle No. 84 and needle No. A I. [MeaQ by polarities.] [Mean by polarities.] Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / / / 33 "2 39 09 39 00 39 02 40 04 39 42 39 20 39 II 12 09 01 03 OS 43 21 11 12 09 00.5 02.5 04.5 42-5 20 5 II 39° 'o'-5 30° oi'.s 39° 53'-5 39° i5'-7 30° 06' 39° 34'-6 Mean, 39° 20^.3 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N. / / / / / / / / 39 43 39 29 39 00 3856 39 08 39 10 3837 3847 44 28 01 57 07 09 40 49 43-5 28.5 . 00-5 S6.5 07- 5 09.5 38.5 48 39° 36' 38° SS'.S 39° o8'.s 38° 43'-5 39° i7'-2 38° 56' JMean, 39° 06'. i Resulting dip, 39° I3'.2. January 26, 1890. Circle in Mag. prime vertical. Local time of beginning, 9:45 a. m. Local time of ending, 11:45 ^- "*• / Circle N. Needle N. 30 58 Magnetic meridian reads 30° 58' S. 30 25 Circle S. " N. 31 24 i( S. 30 07 > lean, 30 44 Polarity of marked end north. Circle east. Face east. .S. o / 3841 41 41 3853 53 53 38° 47' Face west. 39 19 16 17-5 39 15 13 14 39° i5'-7 39° 01 -3 Circle west. Face east. .S. 39 10 10 N. 3906 06 06 Face west. 39 45 42 43-5 N. 39 31 27 29 39° 08' I 39° 36'.: 39° 22'. I Mean, 39° 11^.7 Polarity of marked end south. Circle west. Face west. S. N 39 20 20 39 15 15 15 Face east. 39 45 43 44 N. 39 29 27 28 39° i7'-5 39° 36' 39° 26'.7 Mean, 39° 13' Circle east. Face west. S. N 3844 44 44 3854 54 54 Face east. S. 39 13 10 II. 5 39 10 07 08.S 38° 49' 39° 10' 38° S9'-5 Resulting dip, 39° I2'.4. January 26, 1890. Local time of beginning, 1 2:45 p.m. Local time of ending, 2:00 p.m. Magnetic meridian reads 30° 34' Circle in Mag. prime vertical. o f Circle N. Needle N. 29 58 " S. 31 II Circle S. " N. 30 08 " S. 30 58 Mean, 30 34 MAGNETIC OBSBEVATIONS. 177 Observatioas for dip made at Curasao, West Indies, January 27, 1890, by Lieut. Charles Laird, with dip circle No. 84 and needle No. A I. [Mean by polarities.] Polarity uf ma rked end ,outh. Circle east. Circle west. P'ace east. i Face west. Face east. Face west. S. N. S. N. S. N. S. N. or / / / / / / / 39 OS ; 39 OS 38 41 38 S3 39 43 2,9 28 39 '7 39 13 06 [ 05 40 SI 43 28 IS 10 OSS OS 40.5 S2 43 28 16 "S 39° os'.2 38° 46'.2 39° 3S'So 39° i3'-8 38° 5S'-7 39° 24'.6 Mean, 39° lo' 1 Circle Polarity of marked end north. west. Circle east. 1 Face west. Face east. Face west. Face east. S. N. S. N. S. N. s. N. / / / / / / / / 39 40 39 26 39 18 39 'S 39 03 39 02 3843 38 S3 40 26 14 1 1 07 OS 43 54 A'J 26 16 13 OS 03- S 43 53-5 39° Zi' 19° H'-S 39° 04^.2 38° 48'.2 39° 23'-7 38° 56/.2 Mean, 39° 09'.9 Resulting clip, 39° IG' January 27, l8go. Circle in Mag. prime vertical. Local time of beginning, 9:00 a. m. Local time of ending, 11:30 a. m. / Circle N. Needle N. 30 S2- S Magnetic meridian reads 30° 46' " S. 30 38.0 Circle S. Needle N. 31 26.0 " S. 30 09. s Mean, 30 47. 21124— No. 97 12 178 MAGNETIC OBSERVATIONS. observations for horizontal intensity by the method of deflections with Kevv theodolite magnetometer No. 54, at Cuiapao, West Indies, January 26, 1890, by Ensign L. M. Garrett, with long magnet deflecting at right angles to short magnet, su pended. Distance r = o'".30c a t; Circle readings. Circle readings. "qj a No. A. B. Mean. No. A. B. Mean. / // / // / // / // / // / // E. I 249 43 00 43 20 43 10 W. 2 230 32 00 32 20 32 10 s 3 41 40 42 00 41 50 w w. 4 31 00 31 20 31 10 E. 5 41 20 41 40 41 30 Mean, 249° 42' 10" 230° 31' 40" W. 6 230 17 20 17 40 17 30 E. 7 249 24 20 24 40 24 30 _^ W. 8 16 00 16 20 16 10 E. 9 24 20 24 40 24 30 W. 10 16 20 16 40 16 30 Mean, 249° 24' 30" 230° 16' 43" Computation : — ^ i r' sm 11 (i ~ — H ^ 1' ) Magnet east, 2 it = Magnet west, 2 it = Mean, u = Time of beginning Time of ending, / // = 19 10 30 Sin ti P I — — temp., etc. Ill Logarithms. = 19 07 47 19 09 08.5 ^ 9 34 34-2 , 3:00 p. m. 3:40 p. m. Temp., 29.2 C Temp., 27. 8 8- 13073 g. 22104 9. 99664 0. 00490 Mean, 3:20 / = 28. 5 H 7-35331 MAGNETIC OBSERVATIONS. 179 Observations fur horizontal intensity by the method of deflections with Ke'w theodolite magnetometer No. 54, at Curagao, West Indies, January 27, 1890, by Ensign 1.. M, Garrett, with long magnet deflecting at right angles to short magnet, suspended. Distance r = o"'.4oo Circle readings. ■a (3 Circle readings. tJ : <" 1 ___. « p No. A. i B. Mcan.Nu. ^ '^' : ; i A. U. Mean. / // //////! , c / // / // / // 1 ^- ' ^43 55 40 i 56 00 ss 50 I W. 1 2 ,235 52 30 5300 5245 . : E- 3 55 00 j 55 40 55 20 ' '• ' 1 ^^'- \ 1 1 , 4 S-i 40 5300 5250 1 E. 5 Mean, 55 20 ! 5. i 50 55 35 ; ' 35'' 243" 55 235° 52' 47" W. ! ' 6 [2 1 35 49 40 50 10 49 55 E. 7 243 50 00 50 20 50 lo \V. 1 8 49 40 50 00 4950 y. E. 9 1 50 00 50 20 50 10 IS w. 10 50 00 50 20 50 10 Mean, 243° 50' 10" 235° 49' 58" Computation: — = | r^ sin ;/ (i — — ) / // Logarithms. 1 Magnet east, 2 2< = 8 02 48 i>-> Magnet west, 2 u ^ 8 00 12 8. 50555 Mean, 8 01 30 Sin u 8. 84494 « = 4 00 45 ^2 9. 998 1 1 Time of beginning, 3:15 p. m. Temp., 29.5 C. temp., etc. 0. 00502 Time of ending, 3:35 p. m. Temp., 30.0 Mean, 3:25 '■=29-7 m H 7-35362 Distance r = o™.30o 13 Circle readings. Circle readings. E. 9 18 00 18 40 1820 is W. 10 II 20 ' II 50 i> 35 Mean, 249° iS' 10' / -. i- ,-■■■ sir 230° II' 38" Computation : 7/ f\ P V H ^ ^ r» / // Magnet east, 2 .< ^ 19 14 10 Sin u P Logarithms. Magnet west, 2 « = ig 06 3 Mean, 19 10 2 « = 9 35 I 2 I 3 8. 13075 g. 22149 9. 99664 Time of beginning, 4:05 p. m. Time of ending, 4:45 p. m. Temp., 29.8 C. Temp., 2S.8 temp., etc. 0. 00505 Mean, 4:25 /=2g.3 m H 7- 35393 180 MAGNETIC OBSEEVATIONS. Observations of vibrations, made at Curagao, West Indies, January 26, 1890, by Ensign L. M. Garrett. Civil time, p. m. //I. •5 Teni 1. of magnet. Hor. force magnetometer. Ilor. force thermometer. At commencement . A. I 28.8 C. At end Means I 45 29. 2 29. Corrected means . Scale moving apparently — To the right. To the left. No. of Vib. Time of passing wire. Time of 180 Vib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scale divi- sions. Means and differ- ences. //. m. s. 5 39 08. 5 m. 1. 9 A. m. J. 5 39 39- 7 m. i. 39-7 180 49 3S- 2 10 24.7 189 SO 04. 5 10 24. 8 + 90 39-8 18 40 1 1 . 27 40 42. I 39-7 For 90° 198 50 35-6 10 24. 6 207 51 06.8 10 24. 7 — 90 39-6 36 41 13- 3 45 41 44-5 39-7 216 51 38.0 10 24. 7 225 52 09. 2 10 24. 7 + 360 40.5 For 360° 54 42 15.9 63 42 47- I 39-6 For 90° 234 52 40. 5 10 24. 6 243 53 "-7 10 24. 6 — 360 38-4 Adopted effect 90° 72 252 90 270 43 18.5 53 43- 44 21.0 54 45-5 10 24.5 10 24. 5 81 261 99 279 43 49-6 54 14-2 44 52. 55 16.7 10 24.6 10 24. 7 39-6 Torsion 0.225 Sc.Div. z' = 0^.405 1 -\-tL:=0. 000077 F I Sc.Div. = i'.8 90 5 12. s 60 147.6 99 9 5 12.3 60 148. I Vertical scale, 19, 3 Time for 180th. 49 33-5 Time for 189th. 50 04. 3 10 24. 6 Time, 312^32 =T„= 10 24. 68 Mean tii ne — 180 vib's. 6248 64 90 Vib. Time, I Vib. 3«.47o2 MAGNETIC 0BSEEVAT10l!)S. 181 Observations of vibrations, made at Curasao, West Indies, January 26, 1890, l^y Ensign L. M. Garrelt. Civil time, a. m. Temp, of magnet. Hor. force magnetometer. llor. force thermometer. At commencement. /i. 10 m. 50 29.6 C. At end Means . Correcte II 30 29.7 29.65 1 means . Scale moving apparently — Torsion force. To the right. To the left. No. of Vib. Time of passing wire. Time of 180 Vib's. No. 01 Vib. Time of passing wire. Time of 180 Vib's Torsion. Scale divi- sions. Means and differ- ences. h. m. s. m. s. A. m. s. m. s. 3 II 47-8 10 24. 7 9 3 12 18.9 39-8 180 22 12.5 i8y 22 43- 5 10 24.6 +90 40.0 18 198 12 50. I 23 14-9 10 24. 8 27 207 13 21.4 23 46. lo 24. 6 —90 39-7 39-7 For 90° 36 13 52.6 10 24. 6 45 14 23. 9 39-8 216 24 17.2 225 24 48. 5 10 24. 6 +360 40.5 For 360° 54 14 55-4 10 24. 4 63 IS 26.3 39-7 For 90° 234 25 19.8 243 25 Si-o 10 24.7 —360 38-7 Adopted effect 90° 72 252 IS 57-5 26 22. I 10 24. 6 81 261 16 28.7 26 53- 5 10 24.8 39 6 Tors'no.20oSc.Div. V = 0^.360 I Sc.Div. = i'.S 90 270 90 17 00 24 24. 6 10 24. 6 99 279 17 31- 1 27 55- 7 10 24. 6 i4 _^ 1.000068 05 12.4 60 147.7 9? 9 05 12. 2 60 147.9 Vertical scale, 16. 5 Time for 1 80th. 22 12. 4 10 24.616 Time for 189th. 10 24.65 Mean . 10 24.633 Time, 90 Vib. 3i2».3i6 Mean tin le — 180 vib's. 624'.633 Time, I Vib. =T„= • =.4702 182 MAGNETIC 0B8EEVAT10NS. Time azimuths taken at La Guayra, Venezuela, February 13, l8go, by Ensign L. M. Garrett, with theodolite and chronometer 1596, 13™ 360.4 slow on G. M. T. Before. After. / // / // Reading of mark, A 356 45 00 356 45 00 B 176 45 30 176 45 30 • Reading of circle. Chronometer time, p. m. Telescope. Remarks. A. B. A. m. s. / // / // 8 23 16.0 181 28 00 I 27 30 24 45.0 181 20 00 I 19 30 25 31-0 i8i IS 00 I 15 00 26 36. 181 09 30 I 09 00 27 34- 181 03 30 I 03 30 28 22. 5 180 59 00 56 00 Latitude, 10° 36' 49" N. Longit ade, 66° 56' 43'' W. Solution by : Tan X = sin D cosec S cot | Tan Y = cos D sec S cot i Az=X-|-Y n s=--u/+(9o°-f')] MAGNETIC OBSERVATIONS. 183 Observations for declination made at La Guayra, Venezuela, February 12, 1890, by Ensign L. M. Garretl , with Kew theodolite magnetometer No. 54, with long long magnet suspended, erect. Line of detorsion 100^. Local Scale time. readings. Mean. Azimuth circle, A 29 18 00 Li. m. Left. 1 Right. B 18 20 k, fit. d. d. Remarks : 845 39- I 41.2 40.15 At 8:30 removed torsion weight and 9 00 39-9 40.9 40.40 susjiended magnet. J5 40. 1 40.5 40.30 30 40.4 40.5 40-45 45 40.6 40.7 40.65 10 00 40. 6 40.7 40.65 15 40.7 40.7 40.70 30 40.8 40.8 40. 80 45 40.8 40.8 40. 80 II 00 40.9 41. 40.95 Torsion weight having been sus- IS 40.9 41.0 40.95 pended all night, did not remove 30 40.9 41.0 40.95 magnet after forenoon observa- tions. / // p. m. Line of detors ion 100 Azimuth circle, A 29 18 00 B 18 00 I 00 39-7 39-7 39-70 15 39-5 39.7 39.60 3° 39-3 39-5 39-40 2 30 39-0 39- I 39-05 45 38.8 39- 38-90 3 00 38.7 38-9 38.80 >5 38-7 38- 9 38.80 30 38.7 38.7 38.70 Remarks : After last reading deter- 45 38.8 38.8 38.80 mined axis and scale value of magnet. Determination of scale value of magnet. Determination of axis of magnet. Scale. Circle read- ings, mean of verniers. Value of 10 divisions. Scale, Scale read- ings. Mean. Alter- nate mean. Axis. / // d. 30 29 10 17 50 E 38.8 38.8 38.80 38.90 10 II 20 18 20 I 8.7 21. I l.-|. 90 14.90 26.80 20 29 53 00 18 00 E 38.8 39-3 39-50 39.10 27.00 30 35 00 18 10 I 14. I 15-6 14.85 14.90 27.00 40 16 50 18 30 E 38-2 40.0 39.10 39. 10 27.00 50 28 58 20 18 20 I 14.0 15.8 14.90 14.90 27. CO 60 40 00 17 50 E 39- 39-2 39.10 38.95 26. go 70 22 10 1.8 20 80 03 50 70 22 10 60 40 00 50 58 30 40 29 17 00 30 35 10 20 53 10 10 30 II 30 29 20 Value of one division of scale = i'.82. Scale reading of axis .... 26.95 39- 8d Mean scale reading of east and west magnetic elongation . . Reduction to axis ... . . Azimuth circle reads .... / 23. 30 29 18. 17 = difference = 12.8 Magnetic meridian reads 29 41.47 / // A 28 3 59 00 59 20 B At end of p. m. olDservations .... A 58 20 Mean reading of mark 280 58.83 B 58 40 ^ 280 58 50 Azimuth of mark S. of E . . 105 53-03 True meridian reads 26 51.86 M rgnetic declina tion . . . " 49.61 E. \ 184 MAGNETIC OBSERVATIONS. Observations for declination made Line of detorsion, 130°. at La Guayra, Venezuela, February 13! 1890, by Ensign L. M. Garrett, with Kew theodolite magnetometer No. 54, with long magnet suspended erect. Local time. h. VI. 9 00 15 3° 45 10 00 15 30 45 1 1 00 15 30 45 Scale readini'S. Left. d. 39-3 .39-8 40. I 40. 2 40.3 40. o 40. 2 40.4 40. 6 40.7 40.7 40.8 p. m. 2.15 30 45 3 00 15 30 45 Right. 26.83 40.42 Mean scale reading of east and west magnetic elonga tion Reduction to axis . / 24- 73 29 18.87 ^differences 13-59 ns . . / // A 280 58 20 Magnetic meridian reads . . At beginning of a. m. observatic 29 43. 60 B 58 40 At end of p. m. observations . Mean reading of mark , . . A 58 40 B 59 00 280 58.67 105 53.03 — 280 58 40 Azimuth of mark S. of E. . . . , . 26 51.70 E. 2 51-54 MAGNETIC OBSERVATIONS. 185 Observations for dip made at La Guayra, Venezuela, February 9 and 10, 1890, by Lieut. Charles Laird, with dip circle No. 84 and needle No. A I. (Mean by polarities.] [Mean by polarities.] Polarity of marked end north. Circle east. Face east. o / ^7 09 oS 08.5 N. 37 19 18 iS-S 37° 13'S Face west. 37 33 33 33 N. 37 31 32 31-5 37° 32'-2 37° 22' Circle west. Face east. o / 37 46 44 45 N. 37 42 41 41.5 37° 43'-2 Face west. S. 38 09 08 08.5 N. 37 55 S3 54 38° oi'.z 37° 52'.2 Mean, 37° 37'.S Polarity of marked end south. Circle west. Face west. S. o I 37 42 44 43 N. o / 37 38 40 39 37° 41' Face east. .S. o / 3806 06 06 N. o / 37 S3 52 52.5 37° S9'-3 37° So'i Circle east. Face west. o / 37 II 12 ii.S N. o / 37 19 20 19s 37° iS'-S Face east. o / 37 29 26 27-S N. o / 37 26 22 24 37° 2S'.7 37° 20'.6 Mean, 37° 3S'.3 Resulting dip, 37° 36'.4. February 9, 1890. Local time of beginning, 2:30 p. m. Local time of ending, 4:00 p. m. Magnetic meridian reads 77° 01^.5 Circle in Mag. prime vertical. / Circle N. Needle N, 76 25 " S. 77 09 Circle S. " N. 76 S3 S. 77 39 Mean, 77 01.5 Polarity of marked enc south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / / / 3738 37 30 37 16 37 24 3809 37 SS 37 46 37 43 31 37 12 20 09 S3 41 38 34 33-5 14 22 09 54 43-S 40.5 37° 34' 37° 18' 38° oi'.s 37° 42' 37° 26' 37° Si'-7 Mean, 37° 38^.8 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. N. S. N. S. N. / / / / / / / / 3803 37 46 37 28 37 25 37 25 37 23 37 14 37 20 01 45 25 21 24 22 08 15 02 45-5 26.5 23 24-S 22.5 II 17s 37° S3'-7 37° 24'.7 37° 23'.S 37° i4'-2 37° 39'-2 37° i8'.8 Mean, 37° 29' Resulting dip, 27° 33''.9. February 10, 1890. Circle in Mag, prime vertical. Local time of beginning, 2; 10 p. m. Local time of ending, 4:00 p. m. / Circle N, Needle N. 7 1 02 Magnetic meridian reads 71" 38'' " S. 72 32 Circle ,S. " N. 71 II " S. 71 47 Mean, 71 38 186 MAGNETIC OBSERVATIONS. Observations for dip made at La Guayra, Venezuela, February lo, 1890, l^y Lieut. Charles Laird, with dip circle No. 84 and needle No. Al. [Mean by polarities.] Polarity of marked end south. Circle east. Circle west. Face east. Face west. Face east. Face west. S. N. S. N. S. N. S. N. / / / / / / / / 37 41 37 40 37 21 37 28 37 59 37 44 37 38 37 35 38 37 14 22 58 43 34 29 39-5 38. s I7-5 25 58.5 43-5 36 32 37° 39' 37° 2I'.2 37° 51' 37° 34' 37° 30'. I 37° 42'.5 Mean, 37° 36''.3 Polarity of marked end north. Circle west. Circle east. Face west. Face east. Face west. Face east. S. N. S. " N. S. N. .S. N. / / / / / / / / 3803 37 48 37 33 37 29 37, 24 37 20 37 OS 37 14 03 48 34 30 26 23 06 15 03 48 33-5 29. 5 25 21-5 "5-5 14-5 37° SS'-5 37° 3i'-5 37° 23'.2 37° 10' 37° 43'-5 37° 16/.6 Mean, 37° 30^.05 Resulting dip, 37° 33^.2. February 10, 1890. Circle in Mag. prime vertical. Local time of beginning, i:oo p. m. Local time of ending, 2:00 p. m. Circle N. Needle N. >. Magnetic meridian reads 71° 48' " S. a. m. Circle S. " N. determination. s. J V MAGNETIC OBSERVATIONS. 187 Observations for horizontal intensity by the method of deflections with Kcw theodolite magnetometer No. 54, at La Guayra, Venezuela, February 10, 1S90, by Ensign L. M. Garrett, with long magnet deflecting at right angles to short magnet, suspended. Distance r = o'".3oo. •a Circle readings. Circle readings. *J u s. ^ s No. A. B. Mean. No. A. B. Mean. a r If / // / // / // / // / // E. I 27 39 40 40 00 3950 W. 2 8 22 20 22 20 22 20 i ^ E. 3 39 40 40 00 3950 n W W. 4 22 20 22 20 22 20 E. 5 39 40 3940 3940 Mean, 27° 39' 47" 8° 22' 20" W. 6 8 15 00 15 10 >5 05 E. 7 27 25 20 25 20 25 20 w. « 15 20 15 40 IS 30 s ^ E. 9 25 20 2530 2525 W. 10 IS 40 16 00 IS so Mean, 27° 25' 22" 8° 15' 28" m P Computation: — =^r-''sin «(l — — ) / // Magnet east, 2 ?< ^ 19 17 27 Magnet west,2«= 19 09 54 \ r' Logarithms. 8. 13073 Mean, 19 13 40 «= 9 36 50 Time of beginning, i :45 p. m. Time of ending, 2:30 p. m. Temp., 28. S C. Temp., 28. 2 Sin u P temp., etc. 9. 22274 9. 99636 0. 00487 Mean, 2:04 / = 28.35 m H 7- 35470 Distance r = o™.45o. E. W. E. W. E. Circle readings. No. o / // 20 47 20 47 00 47 00 B. / // 4700 47 00 47 20 Mean. 47 10 4700 47 «° Circle readings. No. o / // 15 07 00 06 40 7 00 6 20 Mean. 7 00 630 Mean, 20° 47' 07'' IS° 06' 4S" W. E. W. E. W. 20 44 40 44 40 4420 44 20 4430 4430 IS 06 20 06 20 06 20 06 00 06 00 06 00 06 10 06 10 06 10 Mean, 20° 44' 30" 15° 06' 10" Computation : H ^\r^ sin u (l- c / // Magnet east, 2 ?< ^ 5 41 22 Magnet west, 2 ?« = S 3^ 20 Mean, 5 49 51 «^2 49 SS Time of beginning, 2:40 p. m. Time of ending, 3:12 p.m. Mean, 2:56 Temp.* 28. o C. Temp., 28. o / = 28. o Sin u temp., etc. H Logarithms. 8. 9S900 8. 69378 9- 99839 o. 00469 7- 35586 188 MAGNETIC OBSERVATIONS. Observations for horizontal intensity by the method of deflections with Kew theodol: Ensign L. M. Garrett, with long magnet deflecting Distance r = o^.^oo. Circle readings. E. W. E. W. E. No. o / // 262 10 40 10 40 10 40 10 50 Mean. / // 1045 lo 50 105s Circle readings. No. 242 54 00 54 00 5400 54 20 Mean. 5400 54 10 Mean, 262° 10' 50" o iA' nc"/ 242° 54' 05 W. E. W. E. W. 261 55 40 55 40 56 00 56 GO 5550 55 50 242 48 00 48 00 48 00 48 10 48 10 48 10 4805 4805 4805 Mean, 261° 55' 50" ° A%l cx' 242° 48' C5 Computation : H =: \ r'' sin « ( I — o / // Magnet east, 2 «< = 19 16 45 Magnet west, 2 k = 19 07 45 Mean, 19 12 15 « = 9 36 08 Time of beginning, 1:15 p. m. Time of ending, 2: 10 p. m. Mean, 1:42.5 Temp., 28. 5 C. Temp., 28. 2 ^=28.35 Sin u P I -- — ,-■2 temp., etc. VI H Logarithms. 8- 13073 g. 22221 9- 99763 o. 00487 7- 35544 ite magnetometer No. 54, at La Guayra, Venezuela. February 11, 1890, by at right angles to short magnet, suspended. Distance r = o'".45o. •a c V, "■A Circle readings. Circle readings. No. A. B. Mean. / // No. A. B. Mean / // / // / // / // / /■ E. I 255 17 30 18 00 1745 W. 2 249 37 30 3800 37 4.'^ ^ E. 3 17 40 1800 1750 W. 4 37 40 3800 3750 E. 5 17 30 18 10 1750 Mean, 255° 17' 48" 249° 37' 47" W. 6 249 36 30 3700 364s E. 7 255 14 5° 15 20 1505 W. 8 36 50 37 20 3705 to E. 9 14 40 15 20 15 00 ^ W. 10 36 40 37 10 3655 Mean, 255° 15' 02" 249° 36' 55" m . , P Computation: — ^\r''smu{\ ^ ) / // Logarithms. Magnet east, 2 ?< = 5 40 01 Magnet west, 2 « ^ 5 38 07 \r> 8. 65900 Mean, 5 39 04 Sin u 8. 69280 « = 2 49 32 -J 9. 99895 Time of beginning, 2:15 p. m. Temp., 28. C temp., etc. 0. 00466 Time of ending, 3:10 p.m. Temp., 27. 5 Mean, 2:42.5 t = 27. 75 m H 7-35541 MAGNETIC OBSERVATIONS. 189 Observations of vibrations, made at La Guayra, Venezuela, February lo, 1890, by Ensign L. M. Garrett. Chro. error, 13'" 3i«.2 slow. Daily rate, i-.ss losing. — - C ivil time, a. m. Tom X uf magnet. Hor. force nagnetometer. Hor. force thermometer. h. m. At comurencement . 10 00 28.5 C. At end ...-., Means Corrected means . 10 35 29. — 28.7s Scale moving apparently — To the right To the left. No. of Vib. Time of passing virire. Time of 180 Vib's. No. of Vib. Time of passing wire. Time of 180 Vib's. Torsion. Scale divi- sions. Means and differ- ences. h. m. s. III. s. h. III. s. 111. J. 2 33 I4. 5 9 2 33 46.0 40. 5 180 43 40- 5 10 26.0 189 44 11-9 10 25.9 + 90 41. 18 34 17-3 27 34 48. 5 40.5 For 90°, 0. 5 198 44 43- 2 10 25.9 207 45 14- S 10 26.0 — 90 40. 36 35 19-7 45 35 S«o 40- S 216 45 45- 7 10 26. 225 46 17.0 10 26.0 + 360 42.5 For 360°, 2. 05 54 36 22.4 63 36 Si- 6 40.5 For 90°, 0. 5 1 234 46 48. 5 15 26. I 243 47 19-5 10 25.9 — 360 38.4 Adopted effect 90° 72 252 90 37 25.0 47 51- 38 27. 6 10 26. 8i 261 99 37 56. 3 48 22. 2 38 59- 10 25.9 40.5 Torsion 0.50 Sc.Div. h I Sc. Div. =l'.8 270 48 53- 5 10 25.9 279 49 24.8 10 25.8 l-|— = I. 00017 F 90 OS 13- I 60 15.59 99 9 5 13 60 155- 5 Vertical scale, 20. 7 Time for 1 80th. 2 43 40. 7 10 25.98 Tin 18 Ti 90 lefor 9th. 2 44 12 10 25. 92 Mean, 10 25. 95 me, Vib. 3i2».975 Mean tin le — 180 vib's. 625. 95 Time, I Vib. =T„= 3'-477S The computation of the results of the observations for magnetic intensity, dip, and variation gives the following values: Locality. Date. Dec. E. Dip. Horizontal intensity (British units). Vera Cruz, Mexico Coatzacoalcos, Mexico .... Salina Cruz, Mexico Port Plata, San Domingo . . . Curasao, West Indies .... La Guayra, Venezuela .... Dec, 18S8 Feb., 1889 Mar., 1889 Dec, 1889 Jan., 1890 Feb., 1S90 1 7 13 6 53 6 59 37 2 28 2 51 / 44 20 43 3 40 2 49 50 39 13 37 35 7. 2890 7. 4300 6. 6667 6. 9841 6. 9496