REPORT ... Durham Geodetic Survey. Durham, N. C. October, 1928 DUKE UNIVERSITY LIBRARY Report... DURHAM GEODETIC SURVEY DURHAM, N.C. OCTOBER, 1923 Report DURHAM GEODETIC SURVEY DURHAM, N. C. October, 1923 R. H. RANDALL & CO. Geodetic and Topographic Engineers Toledo, Ohio DURHAM CuHRIS-IAN & KinG Printrnc ComPpANy 1924 Engineering Library - 1) UY sel i, Letter of Transmittal Duruam, Norru Carona, Ocroser 6, 1923. To the Mayor and Council of the City of Durham, N. C. GENTLEMEN: It is my very great pleasure to transmit to you a report of R. H. Randall & Co. covering the matter of a Geodetic Survey for your city. Progressive cities of the United States are coming rapidly to the realization that accuracy in base line surveys is vital as a basis for all secondary lines and locations and fundamental in city planning. Your acceptance of these facts and your willing- ness to proceed along the most advanced lines has made this survey and report possible. It is safe to say that you now have a survey which will com- pare favorably with any progressive city of the United States and all records together with monuments placed in the streets should be most zealously preserved. Yours respectfully, 3 R. W. RIGSBY, City Manager. RWR/G 5835096 R. H. RANDALL & COMPANY TOPOGRAPHIC ENGINEERS 622 SUMMIT STREET TOLEDO, OHIO OcroseErR 1, 1923. Mr. R. W. Riessy, City Manager, Mr. H. W. Kuerrner, Director of Public Works, Ciry or Duruam, N. C. GENTLEMEN: We are submitting herewith a final report upon the geodetic survey of Durham. We wish to express at this time our appre- ciation of your spirit of help and co-operation. To an unusual degree we have felt that a mutual understanding of aims and re- sults has existed. The function of a report such as this is, in our opinion, two- fold. First, we must record and present to you, in the most con-. venient form, all the data which has been assembled. Second, we must describe all processes and methods used, so that you may have a history and a guide that will enable you with minimum effort to examine into, and follow through any and all parts of the work. These purposes have been kept in mind and it is our hope that the report herewith submitted may fully serve your needs. We are, Yours very respectfully, R. H. RANDALL & CO., By G. D. Wurrmore. GDW/S Contents Arrangement of Report_______ 222 bee awe e ss a8 zea, Minecotetaplesn ini k-crpah ke ween ae ne SO EMOSE ote OEE Foe ys tee at Part I ETO MeEION see ee ere aS Re 2, TER ot 9 Organizations = = eee es Nias oe 5 A et er a h Field work Reconnaissance ys ssa aes Be Oe ee ee ee DT Sethe ol GEenChVEar ks & oe. s0m ane er ee er eee De TE Astronomic Observations _- barnes 2 eee Wy Azimuth __ Ee ARS A Pie ee BE A ee aay Wyatitnd 6. 4 soe! s Me. fee ae ee) BP ee, 1S DT eg ae ee ee Re Sh See. S| 2 UE eee ene | 1] Angular Measurements Biguiipment y 22s ee es Bie Ak _ 14 Method See eS MN ae 13 ee i Linear Measurements ig@ipMmente = en eee ate: Dace 16 PSFOCEOUT EO): 2-25. eee a AS aL ek MR cs: eee ese 16 LQG] Se ee ee Ne Seat atl a cs A 2s in See | (General) Statements ees =k ene i Ne eee ODT Ohieets Work <=... Bar eee pee EN eS ot OS Se 4 DO Computation of Astronomic Observations EE Ne eee 2 es Se asa RL Re Reb eee SN ERD Fst Eatitide. as aoe ee ee ee ae i Azimuth {Ses SES ae Ss 25 Computation of Angular Closures______ ZOE RE O8 LALIT OG Adyustment of Anvular Closures: 2" Seu. 2 es ee Bee y( [5] 535096 Contents—Continued Computation of Azimuths and Bearings... _ 28 Inspection and Check of Taping Field Notes .__.___ 1 2229 Reduction of Slant Distances to Horizontal_.._._...________ 29 Computation of Latitudes and Departures —..________ _ 30 Adjustment of Latitude and Departure Closures ea 31 Computation of Rectangular Co-ordinates ae 32 Computation of Level Differences ee Adjustment of Level Discrepancies =2 (33 Computation of Hlevations______ Eee 33 General Remarks _........ 33 Parr II List of Descriptions, Elevations, Co-ordinates, Azimuths, and Distances, of Precise Survey Points _ __..-_ 36-65 Index for Part ll _....242.2 eee 66-67 ILLUSTRATIONS AND Maps Organization Chart _.._..__ Eee Photograph of Station Monuments or Bench Marks ________ 12 Photograph of Sight Rods_._.___. rr Photograph of Portable Tape Support or Buck —.________ _ 15 Photograph of Taping Party at work _______ _ 17 Specimen Sheet of Taping Notes___.._ es Photograph of forward contact Eee ang () Sketch of Durham Traverse Net BP8} Specimen Angle Sheet een Specimen Distance Reduction Sheet nag Map showing location of Durham Precise Survey Points back cover Arrangement of Report This report, covering the Durham Geodetic Survey, is di- vided, for the reader’s convenience, into two parts; Part I, con- taining general information about the Survey—equipment, meth- ods, results, etc.; Part II, giving a complete list of the perma- nent station marks (hereafter referred to as Bench Marks), semi-permanent points, with descriptions, elevations, rectangu- lar co-ordinates, azimuths, and distances. Use of the Tables in Part II In the tables in Part II, the detailed descriptions of the traverse stations are given on the left-hand side of the page, arranged by lines—that is, line A, line B, etc. On the right- hand side of the page is the corresponding list of elevations, co- ordinates, azimuths, and distances. Anyone desiring to begin a survey from precise control in any certain area would first con- sult the map in the pocket of the back cover, obtain the numbers of the traverse stations which are nearest that area, and look in the index for descriptions and positions for those points. This index is arranged alphebetically and numerically—that is, semi- permanent points, such as lead and oak hubs, are given a num- ber preceded by the letter of the line of which they are a part. Permanent station marks, or bench marks, are numbered through from 1 to 86, the one nearest the center of the city being No. 1, next nearest, No. 2, and the farthest, No. 86. This index will give the pages for the descriptions and the positions. PART I Introduction The City of Durham, previous to 1923, had no system of horizontal or vertical controlling surveys. Neither did it have any sort of property or tax map, the original City Map having been destroyed by fire some years ago. It was proposed, there- fore, to make a new City Map, constructed from actual surveys, and showing on a large scale all streets, alleys, street widths, block lengths and bearings, etc. It was readily seen that, in order to prevent blunders or cumulative errors in the block meas- urements, some sort of precise horizontal controlling survey was necessary, and that this must consist either of triangulation sup- plemented by traverse, or of precise traverse alone, run in adja- cent circuits and adjusted simultaneously. The latter system was finally decided upon for the following reasons: first, the area to be controlled was relatively small, less than four square miles; second, the topography of Durham is comparatively flat, and triangulation would be more expensive than usual due to the necessity of constructing towers; third, precise traverse methods are now so improved as to make it possible to obtain exactly the same results as with triangulation. While the immediate reason for the precise control was the block survey, this control will also be valuable as a basis for underground surveys, location surveys, topographic maps, etc. It may be well to state here the reason for employing an outside organization, such as this Company, for the execution of this geodetic survey work. There is nothing so inherently difficult in this class of work that the City could not, if it so desired, buy the special equipment necessary and develop an organization to do the work; but the ultimate cost would probably be more than it would if executed by a trained and experienced organization, supplied with all the necessary equipment. Results in other cities have repeatedly proved this. A definite standard of accuracy was established at the very beginning. The maximum allowable closure, after an azimuth [9] 10 Report DurHam GropETICc SURVEY adjustment, in any one circuit was fixed as one part in 20,000, and the average must be at least one part in 40,000. The actual closures obtained were an average of 1 : 45682, with a maximum of 1:24584. Traverses of this class are sufficient to control future surveys with an accuracy up to_one part in 20,000. The Durham Traverse Net now consists of 86 permanent stations, or bench marks, and 58 semi-permanent points, (lead or oak hubs) connected by 19.8 miles of precise traverse. ORGANIZATION The chart on this page gives graphically the organization em- ployed upon the Durham Survey. The Supervising Engineer of the district gave enough time to the job to personally supervise and inspect all work. Three of the field men, experienced in geodetic survey work, were furnished by this Company. The other two men were loaned by the City, being qualified as rod- man and chainman in ordinary survey work. It has been found that an organization of this size and character with a supervis- ing engineer giving only part time to the job works out very well, both in quality of results and reasonableness of costs. The office work—computations and adjustments—was done CITY OF DURHAM City Manager R. W. Rigsby Director Public Works H.W. Kueffner R. H. RANDALL & CO. R.H. Randall,Chief Engineer G.D.Whit more,Supervising Engineer Mathematician Chief of Party M. ¥. Poling H. B. Christie Rear-Chainman B.L. Shields Level-Rodman C.F Parrish Computer Instrument-Man|| Head-Chainman C. A.Labbe C.B.Taylor W. E. Chniel Report DurHam Geopetic SuRVEY 11 in the Richmond, Virginia, office of this Company, by experi- enced computers, under the immediate direction of the Supervis- ing Engineer. This was done to avoid the expense and incon- venience of moving the computers to Durham; to get the benefit of the special computing machines, charts and tables, which are in the Richmond office; and to permit the Supervising Engineer to give immediate and constant attention to the computations and adjustments. FIELD WORK REcONNAISSANCE A precise traverse net requires as thorough a field reconnais- sance as does a triangulation survey. In Durham the proposed traverse lines were first drawn on a street map, usually following the main streets, and so spaced as to make all circuits of approxi- mately equal size and with the lines evenly distributed. Next, a field party went over the ground, taking particular note of the following points, which are prime requisites of any precise traverse line: length of sight, visibility, vertical and lateral re- fraction, eveness of grade, and permanency and feasibility of sta- tion sites. If the line as proposed on paper did not meet all of these requirements satisfactorily, the line was shifted one or two blocks either way until the best location was found. While on the reconnaissance, notes were taken of each proposed station site, brought into the office and plotted on a map. The 86 bench marks were then so placed as to be quite evenly distributed, and so that from any one bench mark another one was always visi- ble. The remaining points were to be marked in a semi-perma- nent manner, in concrete or pavement by a lead hub firmly fast- ened and center-marked by a tack, and in earth by a 2” x 2” x 30” oak hub, center-marked by a tack. SetTING oF Bencu Marks Immediately upon completion of the reconnaissance the set- ting of bench marks was begun. About 60 of the total of 86 had been pre-cast in concrete piers, 12 inches in diameter and 36 inches deep, it having been estimated that only about one-third of the bench marks would be placed in structures already in place, such as curbs, sidewalks, ete. The setting of the bench marks was done by laborers from the City’s forces under the su- pervision of the men who had made the reconnaissance. 12 Report Duruam Gropretic SURVEY Two views of the bronze tablet bench mark are shown on this page. The semi-permanent points were set later by the transit party. Two Views oF STANDARD BENCH Mark Usep As PRECISE TRAVERSE STATIONS IN DurHAM GEODETIC SURVEY AstTRONoMiIc OBSERVATIONS Since there was no government triangulation or traverse — within reasonable distance from which to obtain azimuth, or no accurate maps available from which to obtain latitude and longi- tude, it was necessary to observe for time, latitude, and azimuth in order to put the Durham Geodetic Survey upon a true azimuth basis. It was decided to make two azimuth observations, one at - Bench Mark No. 80, in the northeastern part of the City, and one at Bench Mark No. 61, in the southwestern ‘part of the City. Latitude and time were observed for at Bench Mark No. 80, and computed for Bench Mark No. 61, by scaling south and west distances from the 1/4800 scale map of the City. These scaled distances could be considerably in error and still not affect the computed azimuth at Bench Mark No. 61 by as much as one. second of arc. The instrument used on the astronomic observations and Report DurHam Geropetic SURVEY 13 angular measurements was a 6-inch Bausch and Lomb transit, reading direct to 30” and by estimation to 15.” The vertical circle was complete, reading direct to 1’ and by estimation to 30”. Other equipment consisted of a lantern box with vertical slit in front for the ground sight in azimuth, illuminating device for transit cross-wires, electric hand lamps, etc. Azimuth—Inasmuch as the observed azimuths were to be used to control the traverse angles it was necessary to have a final accuracy in each of the observed azimuths of better than (plus or minus) 5 seconds of are. The azimuth party consisted of six men: one observer, one recorder, two timekeepers, one light-keeper, and one helper. The star Polaris was used for the determination of azimuth. Sixty angles were turned between the ground mark and star—that is, 10 sets of 6 repetitions each, (three with telescope direct and three reversed). The recorder kept notes of the initial and sixth readings. The difference between the two readings divided by 6 gave the mean angle for the set. Two watches were com- pared with wireless time on the day preceding the observation, and compared again on the following day. Their constant error and rate of error were thus determined and allowed for. At the instant of pointing the star the observer called “Star” and each time-keeper made an independent note of the time for that sight. These time notes were afterwards compared, and the largst dis- crepancy was 1 second. Latitude—A single latitude determination is made by meas- uring the vertical angle to some star and noting the time at the instant of pointing the star. One vertical angle or altitude con- sists of two measurements, one with telescope direct and one re- versed. Eight such sets were taken for altitude in Durham. The star Polaris was used in the latitude observations and the same party was employed as in the azimuth determination. Time—Observations for time, which consist in determining the error of a watch, were made on two stars, Arcturus, east of the meridian by about 40 degrees, and Procyon, west of the meridian by about 60 degrees, and both nearly on the prime vertical. Eight. sets—a set consisting of two vertical angles or altitudes, one direct and one reversed—were taken on each star, and the time noted at each pointing. Time observations made in 14 Report Duruam Geopetic SurRVEY this manner are sufficiently accurate for use in determination of azimuth. ANGULAR MEASUREMENTS Equipment—The same instrument was used in measurement of angles on the precise traverse lines as was used in the astronomic observations. Sight rods were of a special type, being the outcome of several years of experiments with various types of signals, and are considered to be the best design from the standpoints of accuracy and progress. They are made of well seasoned wood, with a pointed iron shoe. The entire face is 1 inch wide, with a one-eighth inch red strip painted down the center. The center of the sight is the center of the fact of the rod, and the iron point is therefore lined up with the red strip on the face. The sides are painted black to eliminate phase and to make the face of the rod more prominent. Up to a distance of about 1000 feet the red strip can be bisected, and above that distance the white face can be bisected. The rod is brought to a vertical position by means of a plumb bob which hangs in a frame on the back. Special iron tripods, with a slow motion lateral movement on the head, were used to support the rod in’ position, thus avoiding even the small waverings which the steadiest rodman cannot prevent. On very short sights a plumb bob was suspended from the iron tripod and the plumb bob cord bisected. Method—the party used on angu- lar measurement consisted of four Two Views or Sicut Rops, Usen Men: one chief-of-party, who acted As SIGNALS oN DurHay é ee eee as recorder, one observer, and two Report Duruam GropEetic SuRVEY 15 rodmen. Each angle was measured 6 times by the re- peating method, 3 direct and 3 reversed. Vernier readings were made for the initial setting, after the third turning and after the sixth turning. This gave two values, each the mean of three turnings, and the mean of these two values was the measure of the angle. At every station the horizon was closed—that is, both the left-hand and right-hand angles were measured and adjusted so that their sum equalled exactly 360 degrees. The horizon closures thus determined averaged about 4 seconds each. On the main line running directly through from eastern azimuth observation to western azimuth observation the angles were repeated twelve times instead of six. PoRTABLE TAPE Support or ‘Buck’? USED IN PRECISE TRAVERSE TAPE MEASUREMENTS 16 Rerorr Duruam Geroprtic SuRVEY Linear MrasurEMENTS Equipment—A precise traverse tape measurement over -a course corresponds essentially to a single measurement of a base line for triangulation. Practically the same methods and equip- ment are used as in base measurement, and enough precautions taken to insure each course having a measured value correct within about 1 part in 50,000. Probably the most important single piece of equipment in the measuring outfit is the tape. In Durham two steel wire tapes were used, one of 200 feet and one of 100 feet, standardized by the U. S. Bureau of Standards. An Engineer’s spring. balance was employed to give the proper tension, this balance being tested at frequent intervals. Temperature readings were ob- tained from ordinary mercurial thermometers. The portable tape supports, or bucks, (see plate p. 15) are the result of sev- eral years of experience with different types, the style finally adopted and used here being the most satisfactory from the stand- points of accuracy and progress. The tape is held in position at the rear end by an iron pointed hickory rod, about two inches in diameter. When the 200 foot tape was used it was necessary to support it at the 100 foot point as well as at both ends. This support consisted of an upright piece of wood, about 1’x3”36’’, supported on a small tripod, and having holes at one,inch inter- vals into which a nail could be fitted to support the tape. A black and white range pole, held in place by a light tripod, was used for lining in the tape. This was done by eye on short courses and by transit on the longer ones. The level outfit consisted of a Bausch and Lomb wye level and a thirteen-foot extending Philadelphia rod. Procedure—The field party consisted of five men. These were: the chief-of-party, who makes forward contact and keeps a set of check notes; head-chainman, who gives the tension at the forward end of the tape; rear-chainman, who supports and pulls the tape at the rear end; levelman, who operates the level and keeps the notes; and level rodman. (See photograph). After the party had assembled at the station from which the taping was to start, the head-chainman carried the range pole ahead, and by means of bracing tripod, centered the pole over the forward station. As soon as this was done the rear-chainman vi 1 ONid Wy, Aili Ly HOM, ~ 18 Report Duryuam Geropetic SurRvEY lined in the forward buck, which was painted black and white to facilitate sighting. Then, if the 200-foot tape was being used, he lined in the middle support, first for line, then for grade. The man at the middle support placed his hand at the hole which he thought was about on grade, and the rear man motioned him up or down until it was exactly on grade. The nail was then placed in this hole and the tape supported on it. If it was not possible, due to uneven grade, to place the middle of the tape on grade with the two ends, the nail was placed amply high so that the tape would not touch ground between supports, and an eleva- tion was then taken upon the nail. Meanwhile the levelman had set up his instrument, had read the back-sight and figured the height-of-instrument, and was ready to take the side-shot on the middle support if it was not on grade; or, if it was on grade, was ready to take the fore-sight on the forward buck. The rear- chainman then carefully pulled the tape back, hooked it to the FIELD NOTES Party: Christie Sheet No. 13 Taylor Job—Durham TAPING PARTY Chniel Date: May 8, 1923 Shields Parrish LINE “Ww” ELEV. SIDE ELEV. REMARKS AND T. P gis ES SHOT SD-SH LENGTH DESCRIPTIONS 275.633 75.6 200’ tape — 3.520 79.153 2.9 76.3 Weather fair, cool 2.900 76.988 5.065 74.088 74.1 4.1 72.9 4.5 72.5 6.060 70.928 70.9 NW cor. Watts 6.370 77.298 St. & North Rd. 3.1 74.2 100 | 4.3 73.0 100 7.850 80.568 4.580 72.718 4.3 76.3 100 5.115 82.983 2.700 77.868 77.9 Buck | 100 7.385 | 88.843 1.525 81.458 81.5 Buck | 200 5.335 91.973 2.205 86.638 86.6 Buck | 200 Srl 88.3 Sup 100 3.8 88.2 Buck | 100 4.420 87.553 87.6 BM 85 |_126.982 North side North 4.370 91.923 Road 3.1 88.8 Sup 100 3.550 90.328 4.145 86.778 86.8 Buck 3.8 86.5 Sup 0.110 84.823 5.615 84.713 84.7 Buck 2.7 82.1 Sup 5.895 78.928 | BM 84 NW cor., Duke & North Road 4.2 80.6 Sup 4.8 80.0 Sup 8.5 76.3 Buck 3.170 78.943 9.050 75.778 TOP! 5.4 73.5 Sup 7.325 71.618 | W410 5 SS advVJ, JO GNGY LNOUy LY LOVINOD ONINVIL 20 Report DurHam GropEeTic SURVEY hickory handle, jabbed the iron point into the ground about two feet behind the station, and pulled the tape steadily until the zero mark was exactly coincident with the station mark. The front chainman then pulled his end steadily until the spring bal- ance registered the proper tension (usually twenty pounds). When both chainmen had the tape in position, and under correct tension, they gave the contact mana signal. The contact man then made a pencil mark on the copper top of the buck, and gave the signal to release tape. It was then stretched again, and if the second stretching did not check exactly with the first, the performance was repeated until two consecutive stretchings checked exactly; or if several contacts checked very closely a mean was taken. The thermometers, tied to the iron legs of the buck, were then read and recorded. Experiments were made with thermometers tied to the tape and to the iron bucks, and the readings were found to be almost identical. So to avoid the inconvenience and danger of breakage the thermometers were tied to the bucks. The first, or regular set of notes, were kept by the levelman, who recorded the backsights, fore-sights, side-shots, tapes, tem- perature readings, tensions, stations, etc. These notes were kept in duplicate, on specially ruled sheets 814 by 11 inches, punched for a loose leaf file. A sample sheet of these notes is given on page 18. The second, or check set of notes, was kept by the chief-of-party, who recorded, in a regular level book, the tapes, stations, temperatures, and detailed descriptions of stations. Immediately upon completion of one course the two sets of notes were compared. The station was then referenced by tape meas- urements to three or more prominent and substantial objects, these detailed references being recorded along with the general description. After all the precise, slant measurements had been completed, two two-man parties were sent out with 100 foot tapes to make horizontal measurements over each course. These horizontal measurements were made to use as a check on the slant distances, —to catch blunders in the reading of the tape,—one foot, ten feet, etc. It was found necessary, due to congested traffic conditions, to work the down-town section in the early morning hours, from about four to seven o'clock. Rerort Duruam Gropretic SuRVEY 21 LEVELS The levels carried by the precise taping party are run pri- marily for the purpose of getting the differences of elevation be- tween the ends of the tape. However, since the City had no levels which could be used as contro] for the taping levels, and since the taping levels would have to be run in circuits in order to secure a check, it was decided to try to get levels of such quality as could be adjusted and used by the City for ordinary work, such as construction profiles, etc. The levels are not good enough, nor was it expected they would be, to serve as a base net from which other bench marks could be established. Probably at same later date the City will undertake to establish precise ele- vations on all the permanent bench marks. The level was tested for adjustment about every other day; an attempt was made to keep the back and fore-sight distances equal, but not at the expense of taping progress; and precautions were generally taken which would insure ordinarily good levels. Whenever the circuit closures indicated a mistake in any one side, the levels on that side were re-run until the mistake was found, and the course in which it was found was then re-taped. The datum plane used as a basis for elevations is mean sea level, the bench mark in the Court House, established by the U. S. Geological Survey, being taken as the base. This elevation was checked with another bench mark, also set by the U. S. Geological Survey, and located about one mile east of+ Durham. GENERAL STATEMENT The equipment used, and the methods adopted, were selected with two points in mind: first, to obtain traverses with circuit closures averaging 1:40,000, or better; and second, to make the angular work of approximately the same accuracy as the taping— that is, if the taping would average 1:50,000, then the angular measurements should be within 1:50,000. We believe that it is not difficult to get traverses of a slightly higher accuracy than this at slight additional cost, mainly by improving the equip- ment, such as invar tapes instead of steel, 10” theodolite instead of 30”, etc.; but the Durham traverses are well within the limits of accuracy established as being economically correct for the property values involved, and additional accuracy at additional expense was not thought to be justified. in) ho Company. Report DurHAam GropretTic SURVEY For reasons Orrice Work previously stated the office work, or computa- tions and adjustments, was done in the Richmond office of this The necessary computations were: Inspection and checking of all field notes. Computation Computation Computation Computation Computation Reduction of Computation Computation Computation Computation Computation Computation of astronomic observations. of angular closures. of central meridian. of azimuths. of bearings. slant distances to horizontal. of latitudes and departures. of circuit closures. of level closures. of elevations. of rectangular co-ordinates. of corrected distances and azimuths. Adjustment of angular closures. Adjustment of latitude and departure closures. Adjustment of level closures. Before going into the details of these various computations and adjustments it might be well to give a general idea of the net as whole. Reference to the sketch on page 23 will show that the line between the two astronomic observations divides the net into two parts, nearly equal—seven circuits on the north side and five circuits on the south side. Therefore, in order to strengthen the net throughout, this main line was double meas- ured—taped twice, forward and backward, under as different atmospheric conditions as possible; levels run twice; and angles repeated twelve times instead of six. The intention originally was to hold this line practically fixed, corresponding to a base line in triangulation. For reasons given later, however, this scheme was not strictly adhered to. The different phases of the office work will now be consid- ered in order. 23 Report DurHam GEopDETIC SURVEY “SAOQUINN OPIS PUB ‘s.192307 3jNDUID ‘53ND419 Supnoys 44N S3SUSAVUL ISI9SUd WVHUNG JO dVW 24: Rerort DurHam Groprtic SURVEY Computation or AstRoNOMIC OBSERVATIONS Time—First the observed altitudes were corrected for refrac- tion, and from the corrected altitudes the zenith distance com- puted, for each set. The formula then used for computing time observations from observed zenith distances was: | sin 14[ £-+ (®—8) ] sin '4[ €— (@—8)] sine Zt=V/ cos ® cos 6 in which ¢ is the hour angle, 6 the declination, € the zenith dist- ance, and © the latitude. For these computations the latitude was assumed as 36 degrees, later found to be in error by only a few seconds. After ¢ was computed it was subtracted from the right ascension of the star, giving the sidereal time of the obser- vation, which, converted to mean solar time and subtracted from watch time (Eastern Standard time) gave the difference in time between the point of observation and the 75th meridian. The longitude of the place can, then, of course, be readily computed. In the above formula the declination and right ascension are taken from the American Ephemeris and Nautical Almanac. The probable error of the sixteen sets, as figured from the formula. Ea p- ¢. = 0.6745 VY n—1 Vn was + 0.52 seconds of time. The differences between corrected watch time and observed time for the sixteen sets were as follows: . Watch showing 75th meridian time was fast by - Arcturus h m_ 5 Procyon h m_ s5 Seuea OM ToT PSIeo Set I 0 15> 36% 2 31.3 2 34.1 3 31.8 3 36.7 4 35.3 4 28.7 5 30.7 5 28.2 6 32.8 6 32.8 7 32.9 ve 30.1 8 32.7 8 40.0 All computations for the time reductions are filed in Durham Geodetic Survey Records, Vol. I. Report DurHam Geropetic SURVEY 25 Latitude—Observed altitudes were first corrected for refrac- tion, then the hour angle ¢ computed. The formula used to re- duce the latitude observations was ® — [a—(90° — 8) cost] +e where ® equals the latitude, a the corrected altitude, 6 the decli- nation, ¢ the hour angle, and c a small correction taken from Astronomic Tables. As there were eight sets to be computed this work was also arranged in columns. The final computed value for Bench Mark 80 was 35° 59’ 49”, with a probable error of + 5."2 The values obtained for the eight sets are listed below: ° , ” Set 1 2 3 4 35 59 19 5 6 7 8 35 59 41 All computations for latitude reductions are filed in Durham Geodetic Survey Records, Vol. I. Azimuth—The first step in the azimuth computations was the reduction of mean time to sidereal time. This done the hour angle t was then figured by subtracting the right ascension of Polaris from the sidereal time of observation. The formula then used was Sees sin t cos ® tan 6 — sin ® cos t where A is the azimuth, 6 the declination, and © the latitude, and t the hour angle. This result was further corrected for curva- ture, the path of the star being a curve, and not a straight line. The results obtained for the two azimuth observations are listed below: At Bench | Mark 80 At Bench Mark 61 Set 1 182 25 51.0 Set 1 197% 06 21.7 2 182 25 59.4 2 197 O06 25.1 3 182 25 57.7 3 197 06. 11.6 4 182 25 55.8 4 197 06 19.4 5 182 26 00.5 5 197 06 27.7 6 182 26 083 6 197 06 17.2 W NS2 25% 55:0 7:197 06. 28.2 8 182 26 065.1 8 197 06 13.9 9 182 25 58.8 9 197 O06 21.7 10 182 26 07.7 10 107 O6 21.1 26 Report DurHam Gropetic SURVEY ° , “uw ° , wu Mean 182 25 59.93 Mean 197 06 20.76 Probable error = 17/18 Probable error = 1717 The computations for azimuth are listed on a standard form, and are filed in Durham Geodetic Survey Records, Vol. I. ComMPuTATION oF ANGULAR CLOSURES Angular closures for each complete circuit were computed by totaling the right-hand, or first clockwise angles, of all the set-ups on each circuit, proceeding in a clockwise direction, and consider- ing the circuit as a polygon. Thus if a circuit had m courses, the total number of degrees for the sum of the exterior angles should be (n+ 2) X 180° where n is the number of sides or courses, in the polygon. The average error per set up, as indicated by the circuit closures, was aii These computations were tabulated in vertical columns, one sheet for each circuit. The final adjusted values for each circuit ANGLE SHEET F Y Job—Durham Location of Circuit: Mangum—Haywood—Dowd Date: April 28, 1923 Elizabeth—Holloway—Main Note book No. 1&2 STATION ANGLE FIRST CLOCKWISE NORE OCCUPIED BETWEEN ANGLE (HEUMAEES BUDS PAGE Sk ae | ° , ” BM 3 |BM 1—BM 9 179 47 26.3 2— 5 6 + 7.2 9 3— 20 179 54 50.6 4 5 6 + 62 20 9 — F3a 151 16 42.9 Line P joins 5 6 + 18.4 ere F3a 20 — 26 264 28 10.8 cane Q joins 6 6 + 3.3 ere BM 26 F3a — BM 21 281 O01 12.5 6 6 SS ie 21 |BM 26 — BM 31 76 3 55.0 6 6 0.0 31 21— B 2 272 53 00.8) Line F ends 8 6 —12.1 here B2 31 — BM 25 ISL) 10) 1255) 8 6 0.0 BM 25 |B 2— 22 172 20 17.5 8 6 + 17.4 22 |BM 25 — 12 265 56 50.6 Tine E begins} 1— 44 12 — 12.0 ere 12 22 — 10 175 26 45.4 45 12 — 5.7 10 12—A “(| 129 21 59.4 45 12 —11.5 Alt 10—BM 8 180 15 06.9 45 12 — 1.0 BM8 |A i— 5 270 51 10.6 55 12 + 5.5 5 |BM 8— 1 179 21 44.0 55 12 — 0.7 1 5— 8 269 40 23.4 56 12 4.2 Sum 3239 59 49.2 Closure — 00 10.”8 4 per|set-up 0."7 : Report DuruHam GeEopEeTic SURVEY 27 were written in red ink on the same sheet with the field angle, and immediately above it. A sample angle sheet is shown on page 26. These computations are filed in Durham Geodetic Survey Records, Vol. I. ADJUSTMENT oF ANGULAR CLOSURES Since the Durham traverse was in itself complete, and did not depend upon triangulation for precise positions, it was necessary to use some form of adjustment which would consider all the circuits, and their’relation to each other, at the same time. Sev- eral methods have been used in the past, but they have not been strictly speaking, simultaneous adjustments, and oftentimes large discrepancies were forced into one or two of the circuits, making the corrections in these circuits excessive. It was there- fore decided to make a simultaneous adjustment by a least square method, hitherto untried. The conditions imposed were that each circuit should close “flat’’, and since there were twelve circuits there were twelve condition equations, with an unknown for every side. But an inspection of the closures indicated that some of the sides were without error—that is, an adjustment of a side in one circuit which was common to two circuits would increase the closure in the second circuit and necessitate a larger adjustment in the re- maining angles of the second circuit. So, wherever two adjacent circuits had closures of the same sign, (closures always being figured in a clockwise direction and given a plus sign if in excess and minus if deficient), the side common to the two circuits was not included in the condition equations. Assuming these sides to be correct, a tabulation of the condition equations for all of the twelve circuits showed that equation No. 7, for circuit E, had only one side, No. 19. A straight adjustment was made, there- fore, for the angles on that side, and the remaining 11 equations were solved by the usual least square method. There were 19 unknowns in the 11 equations. Weights were introduced in the _ correlate equations for each side, the weight being inversely pro- portional to the square root of the number of set-ups, and in eases of double measurement, of course, a double weight. The solution of these equations gave corrections which made each cir- cuit close “flat”, and the corrections thus obtained were presuma- bly better—more nearly the truth—than could be obtained by any other method. 28 Report DurHam GropEeTIc SURVEY The twelve condition equations for the angular adjustment are listed below: Equation 1 0 —=-+2079— 1— 38 2 0=—+86’6— 4— 5— 6 3 0=— 375+ 54 8 4 0=—41%8-+ 6410111 oe 5 0 =—10%8+12+13-4 14 6 0 —-+ 5475 — 16— 13 : 7 O =-+ 1879 — 19 (Made strght ar 8 0 =-+ 2878 — 14 9 0 =-+ 2777 — 238 — 24 10 0 == — 6274+ 24-4 25 + 26 11 0 =-+ 0973 —26—27— 8 12 0 —=-+ 2174 — 29— 10 All computations on this adjustment are filed in Durham Geodetic Survey Records, Vol. I. CompuTaTION oF AZIMUTHS AND BEARINGS The next step in the angular work was to compute a central, true azimuth, and from it figure the azimuths of all the courses. The observed azimuth at Bench Mark 80 in the eastern part of the city was carried into Bench Mark 1, at Main and Mangum streets, convergence of meridians allowed for, and an azimuth computed. The second observed aximuth, at Bench Mark 61 in the western part of the city was also carried into Bench Mark 1, convergence allowed for and a second azimuth computed. The two azimuths thus brought in to the central point differed by 3176, or an average error per set-up, in the traverse, of 176. A weighted mean of the two carried azimuths was then taken, and the true, or reference meridian, established at Bench Mark 1. (This point is also the origin of rectangular co-ordinates). The zero point of the azimuths is the south point, from whence they increase in a clockwise direction around the circle, due west being 90°, due north 180°, and due east 270°. Upon the establishment of the reference meridian the azimuths of the other courses were computed simply by adding the first clockwise angle of each set-up to the back azimuth of the preceding course, and since the net was geometrically cor- rect, due to the angular adjustment, there were no azimuth dis- crepancies. The bearings were then computed from the azimuths for convenience in figuring latitudes and departures, the bearings Rerort Durwam Gropetic SuRVEY 29 being given in each case to the nearest second. All azimuth and bearing computations are filed in Durham Geodetic Records, Vol. I. Field notes for the angular work are in Durham Geodetic Survey Field Books, Nos. 1 and 2. INSPECTION AND CHECK oF TaPpine FieLp Notes Having completed the angular phase of the work the next step was the careful inspection and check of the taping party’s field notes. This was done by two computers, working individ- ually, who checked all the level notes, computed the differences of elevation between the ends of the tape, computed temperature differences, total slant distances, etc. The original taping field notes are filed in Durham Geodetic Records, Vol. II. RepuctTion oF Stant Distances to HorizontTaL Given the slant distance, the difference of elevation between the ends of the tape, or “grade’’, the temperature, and the tape correction for a certain temperature and tension, the reduction to horizontal was a relatively simple matter. A table, giving cor- rections to a slant distance of 100 feet for grades of from 0.1 DISTANCE REDUCTION SHEET FROM | SLANT GRADE 5 A TOTAL |HORIZONTAL TO DISTANCE . . CORR. DISTANCE 6 i? 629.131 : —.136 | 628.995 27 *| 200 0.8 200 3.5 200 4.3 200 1.5 7 200 ize 200 2.4 100 1.9 78.020 1.4 1378.020 : — .162 |1377.858 35 100 100 27 200 200 95.155 695.155 . — .082 | 695.073 30 Report DuryHam Geropetic SuRVEY _ foot to 15.0 feet was prepared, considerably decreasing the labor on this part of the work. A table was also prepared, for a 100 foot length, showing temperature corrections for every degree Fahrenheit, for a range of 40 degrees. Since the correction given for the tape was at 68 degrees Fahrenheit, all temperature dif- ferences were computed from this. The correction for the tapes was given by the U. S. Bureau of Standards, after a comparison with the U. S. Standard Lengths. The sample “Distance Reduction Sheet”, on page 29 will show at a glance the various steps in this computation. After the final, precise, horizontal distance was figured, it was com- pared with the check distance (chained horizontally by two men, with no corrections applied) to insure against blunders of one foot, ten feet, etc. These computations are filed in Durham Geodetic Survey Records, Vol. III. CompuTaTION OF LaTituDES AND DEPARTURES Having the precise bearing and distance of each course, the latitudes and departures were now ready to be computed. A spec- ial form sheet was used for this computation. Bearings were shown to the nearest second, and distances to the nearest hun- dredth foot. Gifford’s “Natural Sines,” giving the natural fune- tion to eight places for every second of arc, were used in conjunc- tion with a calculating machine. The latitudes and departures were taken only to the nearest hundredth foot. Each cireuit was shown on one page, the latitudes and departures summed for that circuit, and the relative closure figured. A table showing the rela- tive clusures for each circuit is given below: Circuit B 1 part in 46 582.7 CT 5," 360798 Di“ « 41 1865 Ei “ “ 40 0282 F 1 “ € 94 253.9 G 1°“ “ 24 584.0 H 1 “ “ 84 249.7 JI 1 * © 40 80910 K 1 * “ 37 076.8 Pi“ € 41 630.9 Q 1 ©“. 95 08% Wii “= « 36 000.5 Average relative circuit closure is 1 part in 45 682.3. These computations are filed in Durham Geodetic Survey Records, Vol. III. Report DurHam Geropetic SuRVEY 31 ApsuSsTMENT oF LatTitupDE aND DrepartuRE CLosuRES As in the case of angles an adjustment was desired which would not crowd errors into one or two of the circuits, and more- over, the ideal adjustment would be one which would consider all latitude and departure closures as distance closures and would give corrections which would not affect the azimuth to any considerable extent—that is, the correction should be in line with the course and not at right angles to it, since the azimuths had already been adjusted. So the same method as was used for angles—a simultaneous least square adjustment, where the con- ditions were that each circuit should close zero in both latitude and departure, and the use of weights in inverse proportion to the square root of the length of the polygon sides. The condi- tion equations for the latitude and departure adjustment are listed below: Latitude— No.1 0= —032+1+3 2 0= —005+4+5+6 3 0O= +016—3—6—10—l11 4 0= +007—5—7—8 5 0= —002+7+12+4+15 6 0= —0.02+ 16 7 0= —036+19+ 20 8 0= — 0.23 + 22 9 0= + 0.06 — 22 — 20 — 23 10 0= +0.34— 15 — 25 — 26 11 0= —0.36+26+27+8 12 0= —0.08+29+10 Departure— No; 1, 0— =-00l—1—38 2 0= +032—4—6 3 0— —025+3+9+11 +6 4 0= +032—8—9 6 O= +0.12—12—15 6 0= +0.31 — 16 ~ 0— —-[o004— 19 So 0 9 0O= +0.33 — 23 — 24 10 0O= —034+15 + 24+ 25 ll oO= —011+8+27 12 0= —0.16+29 The solution of these equations by the method of least squares gave corrections to each side, which, in turn, were proportioned among the various courses for each side in direct proportion to the latitude and departure distances. New distances were figured from the corrected latitudes and departures, and also, although it was known that the change in 32 Report Duruam Gropetic SURVEY azimuth caused by this adjustment was not great, new azimuths were computed. The average change in azimuth, due to the corrections to latitude and departure, was 1 part in 83 500, while the average change in distance was 1 part in 36 010. It is be- lieved that this adjustment also gives results which are closer to the truth than would be obtained by other methods. The double measured line in the center of the scheme was not held absolutely fixed, as originally intended, because an inspec- tion of the closures indicated that two of the six sides on this main line should receive some adjustment. These sides were, therefore, included in the condition equations, but modified by weights twice as large as for a single measured line. Computations on this adjustment are filed in Durham Geodetic Survey Records, Vol. III. CoMPUTATION OF RECTANGULAR CO-ORDINATES Knowing the corrected bearings, distances, latitudes and de- partures, the next step was the computation of rectangular co- ordinates. Bench Mark 1, the point at Main and Mangum streets, through which the reference meridian had been passed, was chosen as an origin, assigning to it a value of 50 000 North and 50 000 Kast, thus making all co-ordinates which will fall within Durham’s probable area for some years to come of a plus value. Beginning at the origin the northings were added and the southings subtracted, for each consecutive course, to the north value; and eastings were added to, and the westings subtracted from, the east value of the origin. It is thus seen that the rec- tangular co-ordinates increase toward the north and east and de- crease toward the south and west. CompuTaTIONn oF Leve.. DirFERENCES The horizontal, and precise features of the Survey had now been taken care of, but there still remained the levels, which were, as before stated, considered good enough to use as control for profiles, street grades, etc., but not good enough for exten- sive level control. Proceeding around each circuit in a clockwise direction, the back-sights and fore-sights for each separate course were to- taled, and the smaller subtracted from the larger, giving the dif- ference the sign of the larger,—-that is, if the back sights ex- ceeded, going up hill, the sign was plus, and vice versa. Then Rerort Durnam Groprtic SURVEY 33 the courses on each polygon side were totaled algebraically. Thus to figure a circuit closure it was simply necessary to add algebraically the differences of elevation for the sides included in that circuit. The table given below shows the closures ob- tained for the twelve circuits, and the co-efficient of the square- root-of-the-distance term. Circuit Length Level Closure Miles Closure Per Mile XV length of circuit Feet Feet W 2.19 — 0.074 0.034 0.050 P 2.54 0.007 0.003 0.004 Q 1.55 ——Oniod 0.089 0.108 K 2.08 — 0.047 0.023 0.033 F 1.97 0.057 0.029 0.041 B 2.56 — 0.063 0.025 0.039 E 2.73 0.102 0.037 0.062 C 1.67 0.088 0.053 0.068 D 2.39 0.138 0.058 0.089 G 2.24 0.062 0.028 0.041 J 2.92 0.008 0.003 0.005 H. 2.86 0.069 0.024 0.041 ADJUSTMENT OF LeveL DiscrePANCIES Knowing the discrepancies existing in the circuits it was nec- essary to remove them in some way. The least squaye method ‘was selected for this, not because the errors were considered to be of such a class as would require this type of adjustment, but simply because it appeared to involve as small an amount of labor as any other method. Condition equations were stated for _each of the circuits, solved, and the corrections obtained applied to the courses on each side in direct proportion to the. distance. Computation oF ELEVATIONS An elevation had previously been transferred from the Court House to Bench Mark 8, and checked by a tie line from another U. S. Geological Survey bench mark, and it was only necessary to start from this known elevation and add or subtract the differences for each course in order. Since all closures had been removed in the adjustment there were no discrepancies in the elevations. : All computations for levels are in Durham Geological Survey Records, Vol. II. GENERAL REMARKS In closing we wish to say that we believe Durham now has a horizontal control survey of the highest character, and that, in 34 Report DurHam Gropretic SURVEY order to realize fully on the investment, it should be continually used as a control survey. Other cities have legislation requiring that all maps, plats, or surveys made within their jurisdiction, which are to be filed for record, must be tied to, and -co-ordi- nates computed for all the corners on datum furnished by the city. This not only fixes the corner definitely in case of destruc- tion, but enables the City’s engineering department to easily and accurately plot that property on its maps, and know that it is in the proper position. One of the standardized tapes, used on the precise survey, with its correction, will be left with the City for permanent keeping. In the event of destruction or loss of this tape, how- ever, a new tape can be secured, and will be standardized by the U. S. Bureau of Standards for a nominal fee. Whenever a surveyor wishes to do any extensive work, using the Durham precise traverse as control, he should either use a tape standardized by the government, or one that has been com- pared with the City’s standards. This will insure that the tape lengths used on the different surveys are in agreement, an abso- lute necessity for accurate results. The simplest method of mak- ing a comparison locally would be to compare the surveyor’s tape with the City’s tape, using the same tension and having the same temperature for each tape. The difference can then be noted and added to the correction for the ‘standardized tape, after making a temperature correction. The second method would be to select one of the precise traverse lines, preferably one of the double measured courses and as level as possible. The length of this course can be taken from the tables in Part II. The surveyor would then chain this course himself, using his own tape, noting temperature, and always using the same ten- sion. Taking a mean of all his measurements (after a tempera- ture correction), the absolute correction for his tape, for the ten- sion used and the temperature taken as standard, would be expressed by the formula true distance—surveyor’s measured distance true distance length of surveyor’s tape Anyone doing accurate survey work should make it a regular part of the working program to compare tapes with some stand- ard at frequent intervals. Part 1 Laser or Descuirrions, Exxv. cutie, Car eee _ AzmurTHs, anp Distancus, oF Scrvey Ports ‘ : | : ‘ - s - ‘f =— ag | é it AS a Wier - “ots Qe e > ee a ~*~ *: - - -< 7 Ra 36 Bm i Bm 2 A—13 A—14 Report DurHam GeropEeTic SURVEY REFERENCES—PRECISE TRAVERSE LINE “A” Bench Mark at the northeast corner of Main and Mangum streets. North curb of Main, center line of east sidewalk of Mangum. 9.86’ southwest of northeast property corner, cor- ner of No. 101 East Main street. Bench Mark at the northeast corner of Main and Corcoran streets. North curb of Main, center line of east sidewalk of Corcoran. 10.10' southwest of northeast property corner. Bench Mark set in south curb of Main street, at PC of curve going north on Chapel Hill street. In front of No. 343 Main street; about on center line, produced, of Morris street. 13.43’ northwest of northeast corner of No. 343 Main, at granite foundation; 33.36’ east of northwest corner of 345 Main at brick foundation; 32.09’ west of light pole in front of No. 339 Main, at base of pole. Lead hub on north side of Chapel Hill street, about 1.5’ north of center line of sidewalk; east of entrance to No. 116 Chapel Hill street. 4.65’ south of south corner of north stone foundation of No. 116 Chapel Hill street. 16.39’ northeast of northeast corner of south stone foundation at 116 Chapel Hill street. 17.58’ north of tag in telephone pole between 116 and 118 Chapel Hill street. Oak hub on the north side of Chapel Hill street about the center line of brick sidewalk, and about 80’ south of railroad track, 11.94’ northeast of telephone pole, third pole south of railroad tracks, on north side of Chapel Hill street. 31.84’ southwest of second telephone pole south of railroad tracks. 22.15’ south of railroad telephone pole. Bm 15 Bench Mark at the northwest corner of Chapel Hill and Duke streets. Center line of west sidewalk of Duke street. 3.44' southeast of northwest property corner; 43.46’ southwest of northeast property corner; 4.62' northeast of tag in telephone pole on northwest corner: 53.36’ north of southwest property corner. Bm 24 Bench Mark at northwest corner of Chapel Hill and Gregson A—17 streets. On center line of north sidewalk of Chapel Hill; 1.0’ east of center line of west sidewalk of Gregson. 4.76’ south- east of northwest property corner; 41.40’ southwest of north- east property corner; 59.70’ northwest of southwest property corner; 6.19’ northeast of tag in telephone pole on northwest corner. Lead hub in the north sidewalk of Chapel Hill street on the north edge of walk, about 2.5' west of east side of house No. 716 Chapel Hill. 23.63’ northeast of tag in telephone pole in front of No. 716 Chapel Hill street. 52.90’ north of tag in tele- phone pole in front of No. 719 Chapel Hill; 70.00’ east of fire hydrant; 21.65 west of southwest corner of small concrete wall in front of No. 714 Chapel Hill street. Ele- vation Point 401.830 407.328 388.804 390.922 396.284 418.510 416.020 413.978 A13 Al4 15 24 A-17 Rerort DurHam Gropetic SURVEY 37 POSITIONS—PRECISE TRAVERSE LINE “A” Co-ordinates Corrected Corrected North East Course Distance Azimuth 50 000.00 50 000.00 1-2 400.50 124 45 06 50 228.29. 49 670.94 2-6 772.07 121 27 41 50 631.25 49 012.37 50 717.03 48 690.05 6-A13 333.54 104 54 13 50 727.22 48 171.75 A13-Al4 518.40 ‘91 07 34 50 733.37 47 543.37 A14-15 628.41 90 33 40 50 730.58 47 100.92 15-24 442.46 89 38 21 50 706.72 46 344.04 24-A17 = 757.26 88 11 41 38 Bm Bm Bm 39 57 80 58 44 28 22 12 10 8 5 Report DurHam GroprEeTic SURVEY REFERENCES—PRECISE TRAVERSE LINE “A”—(Continued) Bench Mark at the north curb of Chapel Hill street and west line of Milton avenue. 5.15’ east of tag in telephone pole on northwest corner; 7.70' southeast of northwest property corner- stone wall; 50.80’ north of southwest property corner, northeast corner of No. 1001 Chapel Hill; 53.00' northwest of end of small concrete wall on southeast corner; 42.45’ west of fire hydrant. f Bench Mark in north curb of Chapel Hill street, west side of east sidewalk of Chapel Hill road, towards cemetery. About 1.0’ east of east line of No. 1206 Chapel Hill street, 18.08’ west of tag in telephone pole in front of No. 1204; 62.60’ north of base of mail box post; 27.83’ south of northwest corner of No. 1206 Chapel Hill street. Bench Mark at the southwest corner of Holloway and Park. Center line of west sidewalk of Park street, about 1.0’ north of center line of south sidewalk of Holloway; 57.90' southwest of fire hydrant. Bronze plug at the northwest corner of Albright and Holloway, north curb of Holloway, 2.0' east of west property line of Al- bright; 8.22’ southwest of property corner, corner of No. 895 Holloway street. Bench Mark at the northeast corner of Holloway and Al&ton, at the north curb of Holloway, 7.0' west of east line of Alston; 54.50’ northeast of fire hydrant. Bench Mark at the northwest corner of Holloway and Railroad streets. North curb of Holloway, center line of west sidewalk of Railroad. 47.50’ northwest of fire hydrant. Bench Mark at the southwest corner of Holloway and Elizabeth. Center line of west sidewalk of Elizabeth; 2.5’ north of center line of south sidewalk of Holloway. 3.28’ southwest of tag in telephone pole. Bench Mark in south sidewalk of Holloway, in front of No. 514; 2.0' north of center line of south sidewalk; 13.84’ southwest of tag in telephone pole. Bench Mark at the southeast corner of Holloway and Dillard, center line of east sidewalk of Dillard; 0.5’ north of center line of south sidewalk of Holloway; 35.84’ northeast of fire hydrant. Oak hub at the northeast corner of Dillard and Liberty, center line of north sidewalk of Liberty, 2.0' east of brick wall on east side of Dillard. 15.12 northeast of fire hydrant; 49.82’ east of tag in hickory tree; 43.33’ southeast of northwest property cor- ner, small concrete pedestal. Bench Mark'at the northeast corner of Dillard and Main, north curb of Main street, center line of east sidewalk of Dillard. 10.23’ southwest of northeast property corner. Bench Mark at the northwest corner of Roxboro and Main, 1.5’ east of center line of Roxboro, on north curb of Main. 38.70’ northwest of fire hydrant. Ele- vation Point 428.870 408.174 385.186 362.436 338.807 393.532 405.202 415.200 407.990 415.694 410.644 402.365 39 57 80 58 44 28 22 12 10 AT 4 Report Duruam Geropetic SuRVEY POSITIONS—PRECISE TRAVERSE 50 50 49 49 49 49 49 49 49 49 48 49 LINE “A”—(Continued) Co-ordinates North 673.71 612.08 749.56 804.29 820.34 834.67 803.70 803.01 769.07 338.37 954.28 560.59 45 44 56 55 54 53 52 52 52 51 51 50 East 705.51 865.82 978.27 528.26 330.94 264.72 837.63 447.38 030.65 732.32 463.76 623.48 Course A17-39 39-57 80-58 58-44 44-28 28-22 22-12 12-10 10-A7 639.38 841.95 1451.04 1197.43 1066.33 428.22 390.25 418.11 523.93, 468.67 1036.20 762.77 39 Corrected Corrected Distance Azimuth ° UTE 87 02 27 85 48 08 92 09 42 90 46 05 90 46 13 85 51 10 89 53 53 85 20 37 34 42 35 34 57 40 125 48 49 125 10 32 40 Rerort Duruam Geropetic SuRVEY REFERENCES—PRECISE TRAVERSE LINE “B” Bm 25 Bench Mark at the northwest corner of Primitive and Elizabeth, Center line of west sidewalk of Elizabeth, center line of north sidewalk of Primitive; 23.88' southeast of southeast corner of foundation of No. 501 Elizabeth street. B—2 Lead hub at the southeast corner of Elizabeth and Markham at west edge of east sidewalk of Elizabeth; about south property line of Markham. 3.67' northeast of fire hydrant; 42.40’ south of tag in telephone pole; 54.60’ southeast of tag in telephone pole. Bm 31 Bench Mark at the northwest corner of Dowd and Elizabeth, at the north curb of Dowd. 3.0’ west of the center line of west sidewalk of Elizabeth; 55.80’ northwest of fire hydrant. Bm 36 Bench Mark on the center line of south sidewalk of Dowd, 119.0’ east of center line of Hazel street, 12.0' west of west line of No. 606 Dowd street. Bm 41 Bench Mark at the southwest corner of Dowd and Hanover, in path. Center line of south path of Dowd and west path of Hanover. 4.30' northeast of southwest property pipe. B—6 Oak hub on the north side of Dowd road, 4.0' south of north gut- ter 3.0' east of east property line of Hanover. 19.37’ southeast of tag in pine tree; 52.30’ southwest of tag in elm tree; 51.60’ northeast of tag in fence corner; 43.33’ northwest of tag in telephone pole. B—7 Oak hub on south side of Dowd road, about 500.0' south of rail- road, at first bend to north, 4.0’ north of south gutter. 58.60’ northeast of tag in telephone pole; 45.25’ southeast of tag in cedar tree; 42.70’ southwest of tag in oak tree; 22.23’ west of tag in telephone pole. B—8 Oak hub on the east side of Dowd road, about 140.0' north of road leading southeast into pine woods. 3.0’ west of gutter; 9.75' west of tag in telephone pole; 44.62’? north of tag in willow tree. B—9 Oak hub 30.0’ south of center line of Albright road, between one-story yellow frame house with blue trimmings (No. 1329 Albright) and tar paper shingles, and one-story unpainted frame house with hedge in front. 19.12' southwest of tag in large maple tree; 47.94’ west of tag in willow tree; 42.57’ north- west of tag in Henry Horris’ mail box; 64.00’ south of south line of M. Suit’s house. Bm 74 Bench Mark on the west side of Albright road; 2.0' west of west gutter; 62.0’ north of north line of No. 1321 Albright road. Bm 68 Bench Mark at the southeast corner of Albright and Juniper roads. East line of Albright, south line of Juniper; 8.24’ north- east of tag in telephone pole No. 231542. B—12 Oak hub at the southwest corner of Juniper and Park street, about the center line of west sidewalk of Park street, 8.0’ north of edge of sidewalk south side of Juniper. 7.31’ northeast of tag in oak tree; 45.92’ northwest of tag in oak tree; 38.05’ southwest of tag in oak tree; 7.56’ northeast of southwest property pipe. Bm 79 Bench Mark at the southwest corner of Park and Evergreen streets. At the south curb of Evergreen; center line of west curb of Park; 2.81’ east of tag in telephone pole No. 23221. Rerort Duryuam Gropetic SURVEY 41 POSITIONS—PRECISE TRAVERSE LINE “B” Ele- Co-ordinates Corrected Corrected vation Point North East Course Distance Azimuth 405.202 22 49 803.70 52 837.63 a it 390.568 25 50 568.88 52 890.47 22-25 767.00 183 57 00 379.398 B2 50 843.79 52 946.95 25-B2 280.65 191 36 38 383.504 31 51 948.90 52 955.42 B2-31 1105.14 180 26 21 383.157 36 51 924.65 53 598.00 31-36 643.04 272 09 41 376.852 41 51 927.55 54 051.02 36-41 453.03 269 38 O1 379.403 B6 52 138.86 54 096.13 41-B6é 216.07 192 03 00 353.481 B7 52 195.41 54 841.06 B6-B7 747.07 265 39 33 321.904 B8 52 500.33 55 702.91 B7-B8 914.20 250 30 59 370.734 B9 52 146.14 56 241.32 B8-B9 644.47 303 20 19 371.262 74 51 864.37 56 119.41 B9-74 307.01 23 23 42 370.847 68 51 338.60 55 893.10 174-68 572.41 23 17 20 336.617 B12 51 312.61 57 044.08 68-B12 W1W51.27 8960271 17 36 350.080 79 50 868.64 BY 025.55 B12-79 444.36 02 23 24 385.186 80 49 749.56 56 978.27 79-80 1120.08 02 25 09 42 Report Duruam Geropetic SuRVEY REFERENCES—PRECISE TRAVERSE LINE “C” Bm 19 Bench Mark at the northeast corner of Walker and Main, at the C2 C—3 C—5 north curb of Main, center line of east sidewalk of Walker; 4.66’ southeast of fire hydrant. Lead hub at the north curb of Main street, 20.0' east of center line of east sidewalk of Angier street, 22.58’ northwest of tag in telephone pole; 43.81' northeast of tag in telephone pole; 10.12’ southeast of tag in telephone pole. Lead hub in the north sidewalk of Main street, 0.5’ east of east side of stairway to No. 915 Main street, 1.0’ north of center line of north sidewalk of Main. 28.34 southeast of corner of No. 913 Main; 5.13’ northwest of tag in telephone pole; 66.5’ north of tag in telephone pole. Lead hub at the northeast corner of Main and Elm, 2.5’ north of center line of north sidewalk of Main; 0.5’ east of center line of east sidewalk of Elm. 39.40’ southeast of base of mail box; 2.56’ northwest of northeast property corner; 47.26’ northeast of tag in telephone pole. Lead hub on the north side of Main street in front of stairway to Edgemont school. 0.5' north of center line of north sidewalk of Main; 2.19’ southwest of property line (base of stairway) ; 50.58’ northwest of tag in telephone pole; 31.94’ southeast of tag in telephone pole. Report DurHam GroprETIc SURVEY 43 POSITIONS—PRECISE TRAVERSE LINE “C” Ele- Co-ordinates Corrected Corrected vation Point North East Course Distance Azimuth 410.644 8 48 954.28 51 463.76 Ome esl, 411.650 19 48 569.70 52 004.38 8-19 663.46 305 25 37 396.736 C2 48 146.65 52 598.48 19-C2 729.32 305 27 15 376.637 C3 47 907.97 52 941.01 C2-C3 417.49 304 52 10 376.698 C4 47 631.14 53 321.03 C3-C4 470.16 306 04 19 384.008 C5 47 494.83 53 464.78 C4-C5 198.10 313 28 42 373.919 48 47 245.22 53 733.85 C5-48 367.01 312 51 05 4:4 Bm 64 Bm 70 Bm 54 Bm 46 D—10 Report DurHAM GEODETIC SURVEY REFERENCES—PRECISE TRAVERSE LINE “D” Lead hub in center of concrete walkway on west side of Alston street about 200’ north of viaduct; directly in front of corner steps leading up between house No. 216 and 218. 37.50’ north of tag in telephone pole; 5.82' southeast of corner of concrete wall. Oak hub in center of walkway on north side of Alston street, 50’ east of Glenn street, 2.0' east of west line of house No. 316; 4.25' northwest of tag in telephone pole; 15.46’ east of tag in post supporting shed in front of store; 15.81’ southeast of tag in corner of store; 12.74’ south of tack in corner of porch of house No. 316. ; Bench Mark in west curb of Simmons street, center of walkway on north side of Alston street, southeast of house No. 602; 8.40' northeast of tag in telephone pole; 37.50’ north of tag in telephone pole on south side of Alston. Bench Mark at the northwest corner of Alston and Linwood streets, west curb of Linwood, center of north walkway of Alston. 3.15’ east of telephone pole in center of walkway; 12.98' east of telephone pole; 36.40’ west of center of fire plug. Oak hub on east side of Linwood street, 8.0’ east of center line; about 200’ north of Alston street, 10.40’ southwest of tag in small sycamore tree; 17.10' northwest of tag in small poplar tree; 29.22’ northeast of tag in telephone pole on west side of Linwood. Oak hub near west line of Linwood street, on top of small knoll; southeast of small yellow frame house; 1.67’ northeast of small pine stake; 2.31’ southeast of pine stake. Oak hub on east line of Linwood street, east of old hospital; 26.51' south of telephone pole; 53.0’ northeast of black oak tree; 45.14’ southwest of brick pillar at corner of porch to house No. 509. Bench Mark at southeast corner of Fayetteville and Linwood streets. South curb of Fayetteville, east line of Linwood. 2.30’ ‘west of tag in telephone pole; 38.55’ northeast of tag in black oak tree. Bench Mark at the southwest corner of Fayetteville and Um- stead. South curb of Fayetteville, west curb of Umstead, pro- duced; 2.26' east of tag in telephone pole; 41.80' south of tag in telephone pole on east side of Umstead. Lead hub set in asphalt paving, south side of Fayetteville street, east line of private drive, 5.0’ east of east line, pro- duced, of Piedmont avenue; 3.60' north of telephone pole; 28.16’ south of tag in small tree on corner of Piedmont; 16.41’ north- west of tag in end of board on east side of private driveway. Ele- vation 381.644 395.927 397.716 387.356 390.981 392.878 382.678 406.839 395.029 401.703 405.781 Report Duruam Groprtic SurRvEY POSITIONS—PRECISE TRAVERSE Co-ordinates Point North 50 46 763.99 D1 46 264.98 D2 45 592.88 64 44 984.65 70 44 300.54 D5 44 422.66 D6 44 771.26 Di 44 943.14 54 45 017.93 46 45 581.15 D10 46 055.87 53 53 53 52 52 52 51 50 50 50 LINE “D” East Cowrse 543.66 48-50 352.40 50-D1 088.87 D1-D2 848.54 D2-64 577.97 64-70 305.29 70-D5 201.33 D5-D6 675.58 D6-D7 396.64 D7-54 538.52 54-46 681.95 46-D10 45 Corrected. Corrected Azimuth Distance 517.45 534.40 721.92 653.99 735.67 298.77 1157.69 553.13 288.79 580.81 495.91 ° 21 20 21 21 21 114 107 108 105 194 196 33 58 24 33 34 07 31 06 00 08 48 ” 56 15 32 38 45 28 28 13 38 21 41 46 D—l1 Bm 23 Bm Il Bm 82 Bm 81 Bm 75 Report DurHam GeropETIc SURVEY REFERENCES—PRECISE TRAVERSE LINE “D”—(Continued) ' Lead hub in south curb of Fayetteville street, opposite center line of St. Joseph street. 6.36’ east of tag in telephone pole; 40.00’ southeast of telephone pole at corner of St. Joseph Church. Bench Mark set in granite curb on north side of Fayetteville street, center of west sidewalk of Pettigrew street. 3.51' east of telephone pole; 8.50’ west of telephone pole; 13.71’ south of corner of store. Bench Mark set in west sidewalk of Pettigrew street and east line, produced, of Dillard street, 4.26’ east of fence post; 8.37’ northeast of tag in fence post. LINE “E” Lead hub at the northwest corner of Park avenue and Lottie street, north curb of Lottie, 1.0’ west of center line of west sidewalk of Park. 26.85' southwest of tag in telephone pole; 44.35' northwest of tag in telephone pole; 32.52’ northeast of tag in telephone pole; 19.17' southeast of tag in oak tree. Oak hub at the southwest corner of Driver and Lottie streets, in west curb of Driver, about 15.0’ south of south property line of Lottie. 10.57’ northeast of tag in telephone pole; 45.47’ west of tag in telephone pole; 39.80’ south of tag in telephone pole. Lead hub at west curb of Driver street, about 80.0’ north of north side of ball park; 25.05' south of tag in telephone pole; 1.63’ east of tag in telephone pole; 34.20’ north of tag in tele- phone pole. Bench Mark at the northwest corner of Driver and East Main street (Reams avenue), in west curb of Driver, 3.0’ north of north property corner of Reams; 2.99’ northeast of tag in tele- phone pole. Bench Mark at the west curb of Driver, about 100.0’ north of first street north of Angier street, 50.0’ north of old mill; 16.25’ north of tag in telephone pole. Bench Mark at the northeast corner of Driver and Angier streets, at the center line of north sidewalk of Angier, 1.0’ west of center line of east sidewalk of Driver; 3.02’ southwest of northeast property corner, small concrete pedestal. Bench Mark at the south curb of Angier street, about 500’ west of Driver, 3.0’ west of west line of J. E. Parehein’s Grocery Store; 20.35’ east of tag in telephone pole. Ele- vation Point 406.545 396.760 389.534 410.644: 385.186 396.707 384.763 395.730 386.593 403.115 413.710 392.685 Rerort Duryuam GeropEetTic SURVEY POSITIONS—PRECISE TRAVERSE LINE “D”—(Continued) Co-ordinates North DI11 46 648.82 23 80 El E2 E3 78 82 81 75 47 490.26 48 175.61 48 954.28 49 749.56 48 998.30 49 028.75 48 354.29 46 672.75 45 720.42 45 291.68 45 411.12 East Course 50 901.95 D10-D11 51 192.80 D11-23 50 926.75 23-11 51 463.76 11-8 LINE “EK” 56 978.27 56 946.44 80-El 56 437.49 El-E2 56 492.16 E2-K3 56 661.29 E3-78 56 766.27 78-82 56 750.13 82-81 56 370.78 81-75 Corrected Distance 632.45 890.29 735.18 945.89 751.93 509.86 676.67 1690.02 958.10 429.04 397.71 AT Corrected Azimuth On a 200 21 22 199 04 05 158 47 02 214 35 32 02 25 34 93 25 26 355 21 58 354 15 24 353 42 34 02 09 22 107 28 37 48 Bm 63 Bm 55 Bm 50 Bm 48 E—16 Bm 20 Rerort DurHam Geroprtic SuRVEY REFERENCES—PRECISE TRAVERSE LINE “E”—(Continued) Lead hub at the southeast corner of Angier and Smith, south curb of Angier, 1.0’ east of east curb of Smith; 10.12’ north of southeast property corner, corner of concrete wall; 39.18’ southeast of tag in telephone pole. 41.65’ northwest of tag in telephone pole. Lead hub at the northwest corner of Plum and Angier, at the west curb of Plum, 1.5’ north of north curb of Angier; 30.92’ northwest of tag in telephone pole; 6.80’ south of tag in tele- phone pole No. 2328; 25.11’ east of tag in telephone pole. Bench Mark at the northeast corner of Goley and Angier, 0.5’ north of center line of north sidewalk of Angier, east curb line of Goley; 44.63’ east of tag in telephone pole. Bench Mark at the northwest corner of Holman and Angier, center line of north sidewalk of Angier, center line of west sidewalk of Holman; 27.18’ northeast of tag in telephone pole. Bench Mark at the northwest corner of Angier and Alston, 0.5’ north of center line of north sidewalk of Angier; 1.5’ east of center line of west sidewalk of Alston; 5.29’ southeast of north- west property corner, corner of building. Bench Mark at the northwest corner of Main and Alston, west curb of Alston, 0.5’ north of center line of north sidewalk of Main; 13.16’ east of tag in telephone pole. Bench Mark at the northwest corner of Alston and Taylor, cen- ter line of west sidewalk of Alston, center line of north side- walk of Taylor; 57.70’ north of fire hydrant. Oak hub at the northeast corner of Alston and Lottie, 2.0’ south of north gutter of Lottie, center line of east sidewalk of Als- ton; 14.39' west of tag in telephone pole; 6.59’ south of tag in telephone pole; 43.89’ northeast of tag in telephone pole. Oak hub on the east side of Alston street, 1.0’ west of east gut- ter of Alston. 71.0’ north of center line of Eva street. 6.92’ southwest of tag in telephone pole; 40.82’ southeast of tag in telephone pole; 34.93’ east of tag in telephone pole. LINE “F” Bench Mark at the northeast corner of Mangum and Holloway streets, in north curb of Holloway, 1.0’ east of center line of east sidewalk of Mangum, in front of No. 302 Mangum; 10.94" west of fire hydrant. Bench Mark at the northeast corner of Mangum and Hunt streets, 0.5' east of center line of east’sidewalk of Mangum, center line of north sidewalk of Hunt; 55.3’ east of fire hydrant. Bench Mark at the southeast corner of Mangum and Cleveland, 1.5’ south of curb of Cleveland, 1.5’ west of center line of east sidewalk of Mangum, 28’ north of north line of No. 712 Man- gum. 97.5’ southwest of fire hydrant. Ele- vation Point 407.843 393.421 370.894 384.926 381.644 373.919 356.675 357.724 352.598 338.807 401.830 411.198 388.425 386.494 E8 E9 63 55 50 48 45 E15 E16 44 Oo = 20 Report Duruam GeropvEetic SuRVEY POSITIONS—PRECISE TRAVERSE 45 46 46 46 46 AT 48 49 49 49 50 51 52 LINE “E”—(Continued) Co-ordinates North 733.00 021.51 377.38 630.41 763.99 245.22 335.63 172.83 520.98 820.34 000.00 366.71 678.03 160.53 East Course 55 728.84 75-E8 55 278.68 E8-E9 54 453.89 E9-63 53 859.02 63-55 53 543.66 55-50 53 733.85 50-48 54 240.61 48-45 54 317.01 45-E15 54 323.96 E15-E16 54 330.94 K16-44 LINE “F” 50 000.00 50 255.33 1-3 51 161.25 3-9 51 493.52 9-20 Corrected Distance 718.12 534.68 898.29 646.44 342.49 517.45 1202.41 840.68 348.22 299.44 446-84: 1593.82 585.84 49 Corrected Azimuth On pn TP 116 37 44 122 39 22 113 20 15 113 02 32 112 57 23 201 33 56 204 55 53 185 12 50 181 08 37 181 20 07 214 50 54 214 38 20 214 33 10 50 Report Duruam Gropretic SuRVEY REFERENCES—PRECISE TRAVERSE LINE “F”—(Continued) F—S3a Lead hub at the northwest corner of Mangum and Corporation streets, 2.0' east of center line of west sidewalk of Mangum, 4.0' south of south line of No. 801 Mangum, 2.0’ north of curb; 7.15' east of tag in telephone pole; 30.81 northeast of northeast corner of No. 715 Mangum; 6.43’ southwest of tag in telephone pole. Bm 26 Bench Mark at the northeast corner of Haywood and Roxboro streets, in north curb of Haywood, center line of east sidewalk of Roxboro; 46.38’ east of fire hydrant. Bm 21 Bench Mark at the southeast corner of Dowd and Roxboro ' streets, south curb of Dowd, center line of east sidewalk of Roxboro; 11.24’ west of fire hydrant. LINE “G”. Bm 47 Bench Mark in south curb of Umstead street, in front of house No. 312; 10.40’ east of west line of house No. 312; 55.87’ west of tag in telephone pole; 40.60’ southwest of center of fire plug, on north side of Umstead street. Bm 52 Bench Mark at the southeast corner of Umstead and Pine streets, south curb line of Umstead, east curb line of Pine, in front of colored high school. 4.49’ west of tag in maple tree; 32.30' south of tag in telephone pole; 19.75’ east of tag in maple tree. G—8 Oak hub at east of west sidewalk of Pine street, 7.10’ south of south line of house No. 900; 11.95' east of tag in root of small sweet gum tree; 38.97’ north of tag in telephone pole. G—7 Oak hub in center of west sidewalk of Pine street, 5.0’ north of north line of house No. 706; 36.26’ south of tag in telephone pole; 19.40’ north of first corner of concrete steps of walkway to house No. 706; 27.43’ northeast of top of slab on top of brick pillar of porch near corner. G—6 Oak hub on southwest corner of Pine street and Hillside avenue, west line of Pine, south line of Hillside; 8.0' east of east line of house No. 117; 2.75' south of iron pipe in ground; 54.0’ northeast of corner of end brick porch column, house No: 709. Bm 16 Bench Mark at the northwest corner of Pine and Cobb streets, center of west sidewalk of Pine, center of north sidewalk of Cobb, near house No. 528; 10:52' west of iron pipe near corner of house No. 528; 39.90' north of tag in telephone pole, on south side of Cobb street. Bm 17 Bench Mark at the southwest corner of Cobb and MecMannen; 4.26' east of telephone pole; 17.38’ north of tag in tree. Bm 4 Bench Mark in center of west sidewalk of McMannen street on south side of driveway to freight station; 41.65’ north of tag in tel. pole; 21.44’ east of tag in end of wooden track bumper. Ele- vation 385.937 382.054 399.723 383.504 401.703 396.017 410.120 381.174 378.111 355.734 331.690 347.685 401.830 383.108 Point F3a 26 31 46 47 G6 16 Report Duryuam GeEopDETIc SURVEY POSITIONS—PRECISE TRAVERSE 52 52 51 51 45 45 45 46 46 47 47 50 49 LINE “F”—(Continued) Co-ordinates North 264.68 261.75 907.74 948.90 581.15 539.42 493.78 451.06 983.83 209.93 000.00 577.63 East Course 51 504.15 20-F3a 52 062.44 F3a-26 51 991.56 26-21 52 955.42 21-31 LINE “G”. 50 538.52 49 971.42 46-47 49 359.34 47-52 49 333.45 52-G8 49 336.51 G8-G7 49 346.88 G7-G6 49 550.88 G6-16 49 073.84 16-17 50 000.00 49 707.23 1-4 Corrected Distance 104.69 558.30 361.04 964.74 568.63 613.78 957.63 226.34 513.92 51 Corrected Azimuth o ,7 185 49 47 270 18 02 11 19 18 267 33 17 85 44 09 178 27 04 180 19 45 182 37 29 207 16 04 105 07 34 34 43 41 52 Rerort DurHam GroprtTic SURVEY REFERENCES—PRECISE TRAVERSE LINE “G’—(Continued) G—2 Oak hub in center of west sidewalk of McMannen, 3.0’ south of south line of house No. 408; 18.18 north of tag in telephone pole; 14.91’ south of corner of granite step to house No. 408. G—3 Oak hub in center of west sidewalk of McMannen, 6.0’ north of south line of house No. 524; 4.78’ west of tag in telephone pole; 5.15’ southeast of tag in step leading to house No. 524; 24.19’ north of tag in tree. LINE “H” Bm 71 Bench Mark at the southeast corner of Chapel Hill and Under- wood streets, north edge of south sidewalk of Chapel Hill, west edge of east sidewalk of Underwood; 6.46’ northwest of southeast property corner; 6.13’ northeast of tag in telephone pole on southeast corner; 38.96’ southeast of tag in telephone pole on northwest corner; 38.42’ southwest of fire hydrant. H—2 Oak Hub on the south side of Rigsbee road, 1.0’ south of gut- ter, center line of road running north (first road east of Un- derwood avenue); 13.05’ west of tag in telephone pole on southeast corner; 12.14’ northeast of tag in maple tree; 39.05’ southwest of tag in telephone pole on northeast corner; 69.80’ southeast of south corner at base of small concrete wall, east side of concrete steps. H—3 Oak hub on the west side of Swift street, at top of hill, about 45.0’ south of break; 108.0’ northwest of tag in fence post; 23.46’ west of tag in stake on east side of road; 11.19’ south of tag in stake on west side of road. H—4 Oak hub on the north side of road running east and west, 15.0’ west of Swift street, 22.0' southeast of small frame house; 13.30' southwest of tag in ash tree; 16.53’ south of tag in maple Hee 27.95’ southeast of tag in elm tree; 31.16’ east of tag in ree. : H—5 Oak hub on the west side of Neuse street, about 5.0’ north of north line of fourth house from south; 56.20’ northeast of tag in pine tree; 9.86’ east of tag in tree stump; 59.40’ west of tag in fence post, entrance to fourth house from south; 66.10’ ie of tag in fence post, entrance to fifth house from south. H—6 Oak hub on the west side of Neuse street, 17.0’ south of south line of G. Steven’s house (two-story white frame house at top of hill south of creek) ; 9.80’ northeast of tag in elm tree; 47.02" northwest of tag in telephone pole; 49.32’ southwest of tag in elm tree; 21.45’ south of tag in stump. Bm 72 Bench Mark on the east side of Neuse street, about 200’ north of Church, about 43.0' south of end of south line of hedge, cen- ter of path; 43.13’ southeast of tag in telephone pole; 34.78’ east of tag in fence post; 42.15’ northeast of tag in fence post. Ele- vation Point 391.801 374.869 347.685 408.174 399.068 364.440 _ 386.440 376.865 364.080 387.117 412.206 G2 G3 17 57 71 H3 H4 H5 H6 72 Report DurHam GeEoDETIC SURVEY POSITIONS—PRECISE TRAVERSE LINE “G”’—(Continued) Co-ordinates Corrected North East Course Distance 48 997.18 49 507.82 4G2 613.75 48 354.70 49 285.57 G2-G3 679.83 47 734.66 49 073.84 G3-17 655.19 LINE “H” 50 612.08 44 865.82 50 627.05 43 591.84 57-71 1274.07 50 781.39 42 967.80 71-H2 642.84 51 24749 43 087.75 H2-H3 481.29 51 942.12 43 29234 H3-H4 724.13 51 834.10 438 800.54 H4H5 519.55 52 248.78 44 049.34 H5-H6 483.59 53 019.81 44 554.79 H6-72 921.94 53 Corrected Azimuth , ” ° 18 57 31 19 04 50 18 51 14 90 40 23 103 53 30 194 25 54 196 24 38 281 59 59 210 57 42 213 14 46 54 Report DurHam Geropetic SurvEY REFERENCES—PRECISE TRAVERSE LINE “H”—(Continued) Bm 77 Bench Mark at the north side of Main street about the center line of Neuse street, about 90.0' east of east line of “South- gate Memorial Building,’ 28.0’ east of center line of entrance to driveway to “Southgate Memorial Building;” 7.39’ north- east of tag in telephone pole; 15.04 southeast of southeast corner of stone gatepost on east side of driveway; 39.34’ east of southeast corner of west gatepost of driveway. H—9 Oak hub on the north side of Main street, about 74’ east of center line of main driveway to Trinity College; 1.5' south of center line of north sidewalk of Main street; 5.62’ northwest of tag in telephone pole; 26.74’ west of tag in telephone pole; 46.92’ north of tag in telephone pole. Bm 42 Bench Mark at the northeast corner of Main street and Buch- anan road, in grass plot on north side of Main, 3.5’ east of center line of east sidewalk of Buchanan; 8.77’ east of tag in telephone pole; 23.11’ southwest of tag in maple tree; 26.27’ southeast of fire hydrant. Bm 35 Bench Mark at the southwest corner of Main and Watts streets, south curb of Main, 1.5’ west of west curb of Watts; 8.0’ east of east line of porch of No. 1101 Main; 11.93’ northwest of tag in telephone pole; 11.67’ east of tag in telephone pole; 25.50’ northeast of northeast corner of porch foundation of house No. 1101 Main. Bm 27 Bench Mark at the southwest corner of Main and Gregson streets, south curb of Main street, west of west property line of Gregson; 47.66’ northwest of fire hydrant; 18.80’ north of northeast corner of warehouse; 48.24’ southeast of tag in tele- phone pole; 41.34’ south of tag in telephone pole. Bm 7 Bench Mark in south sidewalk of Main street, about 130’ west of Great Jones street; 1.0’ south of center line of sidewalk; 7.96’ southeast of tag in telephone pole; 7.50’ northeast of northeast corner of concrete foundation of bumper; 6.71' north of northwest corner of warehouse brick foundation; 19.18’ northwest of tag in warehouse. LINE “J” Bm 18 Bench Mark at southeast corner of Cobb and South streets, center of south walkway of Cobb, center of east walkway of South; 4.52’ south of tag in telephone pole; 32.91' east of telephone pole on west side of South. J—2 Oak hub about 5.0’ south of center line of Cobb street, east curb line of Matthews street; 13.58’ north of tag in tree; 25.81 southwest of tag in tree; 19.50’ north of stone porch column. J—3 Oak hub four feet south of center line of Cobb street, center of east walkway of Willard street; 10.76’ northeast of tag in tele- phone pole; 22.36’ south of tag in telephone pole; 17.60’ north- west of corner of stone house. Ele- vation Point 412.829 417.363 409.190 399.555 384.215 397.335 388.804 347.685 348.049 351.103 324.509 77 H9 42 35 27 17 18 J2 J3 Rerort DurHam Groprtic SuRVEY POSITIONS—PRECISE TRAVERSE LINE “H”—(Continued) Co-ordinates North East Course 53 674.01 44 871.50 72-77 53 047.46 45 852.61 T7-H9 52 566.40 46 478.68 H9-42 52 236.77 46 839.73 42-35 51 813.09 47 390.73 35-27 50 990.29 48 495.92 27-7 50 631.25 49 012.37 17-6 LINE “J” 47 734.66 49 073.84 47 761.35 48 748.11 17-18 47 791.14 48 454.72 18-J2 47 823.04 47 870.90 J2-J3 Corrected Distance 726.83 1164.10 789.54 488.89 695.07 1377.84: 629.00 326.82 294.90 584.69 55 Corrected Azimuth ° , ” 205 49 54 302 33 50 307 32 21 312 23 45 307 33 31 306 40 06 304 48 29 94 41 04 95 AT 54 93 07 40 56 Rerort DurHAM GEODETIC SURVEY REFERENCES—PRECISE TRAVERSE LINE “J”—(Continued) Bm 29 Bench Mark at northeast corner of Cobb and Duke streets, center of north sidewalk of Cobb, center of east sidewalk of Duke; 41.71' north of tag in telephone pole on south side of pees 37.11’ east of tag in telephone pole on west side of uke. : Bm 30 Bench Mark at the northeast corner of Cobb and Hill, center of north sidewalk of Cobb, center of east sidewalk of Hill; 4.80’ southwest of iron pin in corner of Hill property; 42.61’ north of tag in telephone pole on south side of Cobb; 59.00’ north- east of iron pipe in southwest corner of Hill and Cobb streets. J—6 Oak hub on the north side of driveway of Cobb street, 7.0’ east of west line, produced, of barn, on north side of street; 27.25’ southeast of tag in small cedar; 18.26’ south of tag in fence post; 32.82’ southwest of tag in fence post. Bm 40 Bench Mark at the southwest corner of Cobb and Cross streets, 2.17' southeast of property corner (Iron pipe); 26.90’ south- east of corner of catch basin; 47.45’ southwest of east catch basin. Bm 37 Bench Mark at the southeast corner of Shepherd and Proctor streets, center of east walkway of Shepherd, center of south walkway of Proctor; 5.00' southwest of tag in telephone pole; 32.80’ east of tag in telephone pole on north side of Shepherd. Bm 32 Bench Mark at the northwest corner of Shepherd and Morehead streets, center of west sidewalk of Shepherd, north curb of Morehead; 9.62’ southwest of tag in telephone pole; 45.82’ west of center of fire plug. J—10 Oak hub about 5.0’ south of center line of Morehead street. 33.34 north of tag in sycamore tree; 40.98’ northeast of tag in cor- ner of porch of house No. 1007; 45.61' south of tag in corner of porch of house No. 1006. Bm 66 Bench Mark at the southeast corner of Chapel Hill and More- head streets, south line of Morehead, 8.0' east of west line of Chapel Hill; 15.13’ northwest of tag in corner of building; 24.42’ east of tag in corner of white store building. Bm 61 Bench Mark in center of east sidewalk of Chapel Hill road, at north side of entrance to Maplewood Cemetery; 6.17’ southeast of tag in telephone pole. LINE “K” K—1 Lead hub in the east sidewalk of Morris street, 23.0’ south of south property line of Randolph street, 2.0’ north of south property line of No. 222 Morris; 2.77' northwest of corner of small concrete pedestal at north property line of No. 220 Morris; 27.60’ northeast of tag in telephone pole; 6.94’ south- east of tag in tree. Bm 14 Bench Mark at the southeast corner of Morris and Corporation streets, north curb of Corporation, center line of east side- walk of Morris; 18.50’ northeast of street signpost. Ele- vation 350.881 368.605 375.234 372.858 388.787 356.885 404.721 411.415 408.174 388.804 399.631 363.932 Point 29 30 J6 40 37 32 J10 66 61 14 Report DurHam GropeTic SURVEY 57 POSITIONS—PRECISE TRAVERSE LINE “J”—(Continued) Co-ordinates Corrected Corrected North East Course Distance Azimuth 47 862.69 47 51243 J3-29 360.66 96 18 44 47 881.20 47 003.15 29-30 509.62 92 04 52 47 877.73 46 786.05 30-J6 217.13 89 05 07 47 863.11 46 262.92 J6-40 523.33 88 23 55 48 305.36 46 295.80 40-37 443.47 184 15 07 48 784.02 46 260.60 37-32 479.95 175 47 40 48 799.41 45 351.90 32-J10 908.83 90 58 14 48 842.50 44 279.85 J10-66 1072.92 92 18 06 49 141.75 44 413.05 66-61 327.56 203 59 40 50 612.08 44 865.82 61-57 1538.46 197 06 58 LINE “K” 50 631.25 49 012.37 51 589.50 49 10046 6-Kl1 962.29 185 15 12 52 496.76 49 16446 KI-14 909.51 184 02 11 58 Report DurHam GEoDETIC SURVEY REFERENCES—PRECISE TRAVERSE LINE “K’—(Continued) Bm 13 Bench Mark at the southwest corner of Corporation and Foster streets, north curb of Corporation, 1.0’ east of center line of west sidewalk of Foster; 8.52' north of fire hydrant. Bm 34 Bench Mark at the northwest corner of Trinity and Orient streets, center line of west sidewalk of Orient, north sidewalk of Trinity; 25.41’ east of tag in telephone pole. K—6 Oak hub under stake, 3.0' east of east line of No. 508 Hargrove street, 1.0’ north of north path to Trinity Avenue; 10.19’ south- west of tag in stake. K—5 Oak hub on the south side of Hargrove street, 3.0’ east of west line of No. 507 Hargrove, about south property line of Har- grove; 18.97’ northeast of northwest corner of foundation of No. 507 Hargrove; 3.85’ west of tag in maple tree; 28.55’ south- west of tag in sycamore tree. K—4 Oak hub at the northeast corner of Hargrove and Foster streets, 2.0’ east of east gutter of Foster, about north property line of Hargrove (in grass); 7.0’ south of south line of No. 802 Foster; 17.84’ southwest of corner of brick foundation of No. 802 Foster; 40.63’ north of tag in telephone pole; 43.76’ north- east of tag in telephone pole. LINE “P” P—1 Oak hub on the south side of Green street, about 320’ east of Duke street, 29.0’ west of west line of Hibberd house; 14.68’ northeast of tag in stake; 104’ southeast of southeast truss of transmission line tower; 45.07 southeast of tag in cedar tree. Bm 65 Bench Mark on the south side of Green street, 212’ west of cen- ter line of Eblin ave., 16.0 east of east line of wire fence; 2.0' south of south gutter of Green street; 30.33’ southeast of tag in fence post; 46.50’ east of tag in fence -post. Bm 67 Bench Mark at the southwest corner of Green and Glendale streets, 3.0' southeast of street sign post; 31.32’ southwest of tag in corner fence post; 25.09’ south of tag in sweet gum tree; 38.49’ southeast of tag in fence post. Bm 59 Bench Mark on the north side of Markham street, 3.0’ south of north gutter; 200’ east of center of Glendale street; 13.08’ southwest of tag in stake; 9.65’ southeast of tag in stake. Bm 62 Bench Mark at the northwest corner of Mangum and Markham streets, 5.0’ east of west curb of Mangum; 5.0’ north of north gutter of Markham; 10.56 east of fire hydrant; 21.70’ south of tag in telephone pole; 56.10’ southwest of tag in hickory tree; 4.21' northeast of center of, manhole. P—6 Lead hub on west side of Mangum street, 5.0’ east of west curb; 2.0' south of south edge of bridge over N. & W. R.R. 14.7’ northeast of fire hydrant; 16.98’ northeast of tag in telephone pole; 2.04’ south of tag in end of guard plank, west side of bridge; 25.57’ west of tag in guard rail post. Ele- vation 360.814 335.457 339.342 362.504 357.602 358.352 360.814 365.581 350.658 365.861 368.094 384.382 391.936 400.591 Point K5 K4 13 60 Pl 65 67 59 62 P6 Report Duruam Geropretic SURVEY POSITIONS—PRECISE TRAVERSE LINE “K”—(Continued) Co-ordinates Corrected North East Course Distance 52 509.06 49 732.95 14-13 568.64 53 841.03 48 475.24 53 840.18 49 335.63 - 38-34 860.39 53 636.87 49 529.96 34-K6 281.24 53 312.12 49 551.73 K6-K5 325.48 53 388.40 49 772.87 K5-K4 233.93 52 509.06 49 732.95 K4-13 880.25 LINE “P” 55 513.80 48 495.87 55 805.81 48 798.54 60-P1 420.57 55 783.29 50 780.62 PI1-65 1982.21 55 788.32 51 335.55 65-67 554.95 55 488.43 51 551.46 67-59 369.53 55 361.26 52 211.96 59-62 672.64 54 862.41 52 109.21 62-P6 509.32 59 Corrected Azimuth 268 270 316 356 250 ~ 02 226 270 269 324 280 11 yee 45 38 03 24 17 35 09 56 58 04 35 58 01 37 39 03 28 50 14 46 53 52 38 21 60 Report Duruam Geropetic SuRVEY REFERENCES—PRECISE TRAVERSE LINE “P”—(Continued) Bm 56 Bench Mark at the northeast corner of Lynch and Mangum; center line of east sidewalk of Mangum, center line of north sidewalk of Lynch; 9.55’ northwest of fire hydrant; 40.97’ north of southeast property corner; 65.7' northeast of south- west property corner; 35.76’ east of tag in telephone pole; 5.84’ southeast of tag in telephone pole. Bm 43 Bench Mark at the northeast corner of Mangum and Trinity Q—4 ave., 0.5’ east of east property line of Mangum, 1.0’ north . of center line of north sidewalk of Trinity; 11.41’ southeast of fire hydrant; 10.27’ northwest of tag in telephone pole; 36.6’ north of tag in telephone pole. Lead hub at the southeast corner of Mangum and Geer streets, 1.0' west of center line of east sidewalk of Mangum; 11.08’ northeast of tag in telephone pole; 38.45’ east of tag in tele- phone pole; 38.17’ south of tag in telephone pole. LINE “ j $2 , ‘Ti } ‘ a qT bis Envelope Contains: oe _ MAP OF DURHAM, N.C. ra eg Showing Bench Marks and ite } — Semi-Permanent Points In Precise Traverse Scheme . : Lt i} 2 | * ey e iW l ON ©) I OA GK % mx DNWAKG iy a me c \ ae i eee Seo \ = Rr ¥ s : oxy J oy ‘ = %. 0, %; Ne © % > %, % a 2 2 x o gs ie AT oY oe BEES Zi || sr a als %, —¥ a) : x, a! sto py bed on RSs NS ——- ~ XN 4 BLACKWELL EN aw © o @ 9 Ww D961R g Durham geodetic surve 526