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QUIDE TO 
 
 WASHINGTON 
 
 AND ITS 
 
 WITH 
 TWO MAPS. 
 
 Scientific 
 Institutions 
 
 international congress of geologists. 
 
 FIFTH SESSION, WASHINGTON. 
 1891 
 
 OPENING SESSION, WEDNESDAY, AUGUST 20, 2 P. M. ^ 
 COLUMBIAN UNIVERSITY. 
 
 Prepared by the Local Committee for the use of tiie Congress. 
 

 LOCAL COMMITTEE. 
 
 Gardiner G. Hubbard, Chairman. 
 
 Charles D. Walcott, Secretary. 
 Marcus Baker. vS. F. Emmons, Prof. S. P. Langley, 
 
 Dr. G. F. Becker, G. K. Gilbert, W. J. McGee, 
 
 Whitman Cross, G. Brown Goode, Dr. T. C. Mendenhall, 
 
 Dr. \V. H. Dall, Arnold Hague, Maj. J. W. Powell, 
 
 Dr. David T. Day, Jos. P. Iddings, Hon. Edwin Willetts, 
 
 Maj. C. E. Dutton, U. S. A. Bailey Willis. 
 
 EXECUTIVE COMMITTEE. 
 
 Gardiner G. Hubbard, Chairman. 
 Dr. W. H. D.vll, G. K. Gilbert, Maj. J. W. Powell, 
 
 S. F. Emmons, Arnold Hague, Charles D. Walcott. 
 
 COMMITTEE ON HALLS AND PLACE OF MEETING. 
 
 Dr. W. H. Dall, Chairman. 
 G. Brown Goode, ^' ■ J- McGee. 
 
 COMMITTEE ON PRINTING. 
 
 Maj. J. W. Powell, Chairman. 
 Dr. T. C. Mendenh.\ll. Hon. Edwin Willetts. 
 
 COMMITTEE ON SHORT EXCURSIONS. 
 
 G. K. Gilbert, Chair77tan. 
 Maj. C. E. Dutton, U. S. A. Bailey Willis. 
 
 COMMITTEE ON FINANCE. 
 
 Gardiner G. Hubbard, Chairman. 
 Marcus Baker, Jos. P. Iddings. 
 
 COMMITTEE ON ENTERTAINMENT. 
 
 Arnold Hagu,E, Chairman. 
 Whitman Cro.ss, •''. : Jos. P. Iddings, 
 
 Dr. David T. Day, *••"" Bailey Willis. 
 
 By Tranflfer 
 Qeologicat Survey 
 
 NOVg - ^^^ 
 
+^' 
 
 "xlhe DistPiei of Columbia. 
 
 The District of Columbia is the permanent seat of government of the United 
 States, and Washington is the capital city within its hounds. Its exact site was cho.sen 
 by President Washington in accordance with a resolution passed by Congress 
 July ID, 1790, which .specified that the location should be upon the banks of the 
 Potomac river between certain limits. This choice was reached after a heated sectional 
 contest, and conformed to the declaration that " the site of the future capital should be 
 as near as po.ssible the centre of wealth, of population, and of territory." 
 
 The District was originally ten miles square ; its centre was very near the spot 
 occupied by the W^ashington Monument, and jurisdiction was ceded to the general 
 government by the States of Maryland and Virginia. The boundaries of the District 
 as originally defined are shown upon the accompanying geological map. When the 
 site was chosen Georgetown had been a thriving trading point, with extensive foreign 
 commerce, for nearly a hundred years, and Alexandria was also a prominent .settlement, 
 but the ground occupied by the present City of Washington was for the most part 
 unimproved. 
 
 %hc (Bit2 of tQazhington. 
 
 The ground plan of the capital is the work of Major L'Enfant, a young French 
 engineer residing in Philadelphia, chosen by Washington for this purpose. The plan 
 was made after a careful study of the phj^siography of the District, and shows a wonder- 
 ful appreciation of the requirements of the caj^ital of a great nation. 
 
 The Capitol is the centre of this plan. The north and south and east and west 
 lines passing through that building divide the city into four quarters. Either side from 
 the meridian line the streets are numbered : First street, Second street, etc. Each 
 way from the east-west line the streets are named in order from the alphabet : A street, 
 B street, etc. Besides the lettered and numbered streets there are many avenues, 
 named after states of the Union. These a\enues run in directions diagonal to the 
 streets and are so arranged that .several of them intersect at certain important points — 
 as at the White House and at the Capitol. 
 
The streets and avenues of the city are so wide (80 to 160 feet) that in most 
 cases only the central part is used for pavement and sidewalks, leaving a strip on either 
 side which holders of adjoining property are allowed to improve with flowers, shrubs 
 and trees, but may not encroach upon with buildings. 
 
 The largest park within the city limits is that known as the Mall, which lies 
 between the Capitol and the Washington Monument. In various divisions of this park 
 are situated the Smithsonian Institution, the National Museum, and other scientific 
 l)ureaus and museums. (See map). Between the White House grounds and the 
 Monument is the President's Park, commonly known as the " White I^ot." 
 
 Within a few years the park area of the city will be more than doubled by the 
 improvement of the grounds now being reclaimed, by dredging and filling, from the 
 malarial fiats of the river. This land adjoins the Mall on the west and extends south- 
 ward to a point opposite the Arsenal grounds. 
 
 One of the most beautiful features of the city is the great number of small parks, 
 most of them situated at points of intersection of several avenues, while in other cases 
 one or more squares are thus occupied. Perhaps the most beautiful of these small 
 parks is Lafayette Square, situated in front of the White House, between Pemisyl- 
 vania avenue and H street, and surrounded by houses with which many events of 
 historic interest are connected. It contains a great variet}' of beautiful trees, many of 
 them exotics. In the centre of this park is an equestrian statue of Andrew Jackson, 
 seventh President of the United States. At the southeastern corner of the park is the 
 monument recently erected to the memory of Lafayette and his compatriots. Count de 
 Rochambeau and Chevalier Duportail, of the French army, and Counts D'Estaing and 
 De Grasse, of the French navy, who served as allies in the closing years of the Revolu- 
 tionary war. The statue, which was ordered by Congress at a cost of $50,000, was 
 designed by the French artists, Falquiere and Mercie. 
 
 On Vermont avenue are three pretty parks. McPherson Square, situated 
 between I and K streets, contains an equestrian statue to General J. B. McPherson, 
 erected by the Society of the Army of the Tennessee. Two blocks further up Vermont 
 avenue, at the intersection of Massachusetts avenue, is Thomas Circle, in the centre of 
 which is a statue of General George H. Thomas, erected by the Society of the Army 
 of the Cumberland. Two blocks still further out Vermont avenue is Iowa Circle. 
 
 On Connecticut avenue, which leads off" in a northwesterly direction from 
 Lafayette Square, is Farragut Square, between I and K streets. In this is a statue of 
 Admiral David G. Farragut. Four blocks up the avenue is Dupont Circle, in the 
 centre of which is a statue to Rear Admiral Samuel F. Dupont. 
 
 In Scott Circle, at the intersection of Sixteenth street and Massachusetts 
 avenue, stands an equestrian statue of General Winfield Scott. 
 
 On East Capitol street, in the eastern section of the city, is the fine Lincoln 
 Park, with a statue representing the emancipation of the slave. 
 
Besides the parks above mentioned the visitor will find many others, at short 
 intervals, on nearly all the {principal avenues of the city. The grounds about the 
 Naval Observatory, the Arsenal, and at the Congressional Cemetery are also improved 
 as ]-)arks. 
 
 The Botanical Gardens are situated on Pennsylvania avenue, between First and 
 Third streets. They cover ten acres of ground, and are beautifully laid out with trees, 
 shrubs and flowers. They may l)e considered as forming a part of the Mrdl, although 
 enclosed l)y an iron railing. Admission may l)e had between 9 a. m. and 6 p. m. 
 every da}- except Sunday. The grounds and greenhouses are well worth a visit. 
 
 %hc Eoologieal IPark. 
 
 Thiv grounds of the new Zoological Park in the near suburbs of the city lie on 
 both sides of Rock Creek, just north of Woodley lane. They compri.se 166 acres. 
 The land was purchased by Act of Congress in 1889 at a cost of nearly $200,000. 
 Already the park is enclosed, and several structures suitable for the use of the animals 
 have been erected. A considerable number of North American animals have been 
 placed in their new home, and an excellent nucleus started for a national zoological 
 garden. A number of the larger Rocky Mountain animals have been captured in the 
 Yellowstone National Park, and will be transferred to Washington for the Zoological 
 Park earh' in the autumn. 
 
 The park is most picturesquely located and admirably adapted for its purpose. 
 It is under the direction of the Smithsonian Institution. 
 
 %h^ (SapiJol. 
 
 The Capitol as it now stands is the result of several additions to and changes of 
 the original building. The central part, exclusive of the dome, represents the original 
 design by Mr. Stephen Hallet. The two wings of this part, erected in 1793-1811, 
 were destroyed by the British in 1814. but were soon rebuilt with the connecting 
 portion and a wooden dome. The extensions on the north and south, containing the 
 present legislative chambers, were added 1851-1867, after the plans of Mr. Thomas U. 
 Walter, and the great iron dome, by the same architect, was completed in 1S63. 
 
 The length of the building is 751 feet, its greatest width 320 feet, and the dome 
 rises 307 feet above the foundation. 
 
 In the different facades of the Capitol are 134 beautiful Corinthian columns, 
 100 of them monolithic. The material of the new wings is white marble, that of the 
 older part sandstone. 
 
 5 
 
At the eastern front of the building, flanked b}- a double row of columns, is a 
 portico 1 60 feet long, upon which most of the Presidents have been inaugurated. 
 
 The Capitol contains the legislative chambers of the Senate and of the House 
 of Representatives, the United States Supreme Court Room and Congressional 
 Library. 
 
 The rotunda of the Capitol is 96 feet in diameter at its base, and 185 feet high, 
 to a canopy 65 feet in diameter. In the rotunda are eight large paintings by American 
 artists, four of them commemorating events in the discovery and settlement of the 
 country, and four representing scenes in the Revolutionary war. The frieze, 10 feet 
 in height, is likewise historical in character. In the canopy is an allegorical fresco, 
 the apotheosis of Washington, by Brumidi, who also began the frieze. 
 
 From the rotunda one can ascend to the dome and to the cupola above, from 
 which a beautiful view of the city may be obtained. The dome is crowned by a bronze 
 statue of the Goddess of Freedom, by Crawford, an American sculptor. The dome is 
 135 feet 5 inches in diameter at its base. 
 
 At the entrance to the rotunda from the eastern portico is a bronze door repre- 
 senting in its relief figures the history of Columbus and his discoveries. There are 
 also heads of many sovereigns and discoverers whose names are associated with the 
 discovery of America, and of historians who have written upon the subject. The door 
 was designed by Randolph Rogers, in 1858. Another fine bronze door is at the eastern 
 entrance to the Senate wing. This was designed by Crawford, and was cast at 
 Chicopee, Massachusetts. 
 
 The assembly halls of the Senate and of the House of Representatives, and the 
 rooms connected with them, are ornaniented with many frescoes, paintings, and 
 artistic decorations. Attention is especially called to two large paintings by Thomas 
 Moran, situated in the vestibule to the ladies' gallery of the Senate chamber. One of 
 these represents the "Grand Caiion of the Yellowstone," and the other the "Grand 
 Caiion of the Colorado." Both are well worthy of study. Among the mi.scella- 
 neous paintings which adorn the halls and galleries are " Westward Ho," by L,eutze, 
 and the " Signing of the Declaration of Independence." 
 
 Between the rotunda and the House wing of the building is the National Hall 
 of Statuary. To this collection each State of the Union has been invited to contribute 
 two statues of prominent citizens. Many of them have already done so. 
 
 %h2; tnhil'e House. 
 
 TiiK Executive Mansion, or White House, is situated in a park between the 
 Treasury and the State, War and Navy buildings. It was erected in 1792-1799, after 
 the designs of Mr. James Hoban, and is said to be similar to the palace of the Duke of 
 
I^einster. in Dublin. Its popular name is said to have its origin in the fact that for a 
 Ioul; time after its completion it was the only white building in the city. 
 
 The largest of the reception rooms is open to visitors from lo a. m to 3 p. m. 
 Concerts by the Marine Band are given at 6 o'clock every Saturday afternoon during 
 the summer in the grounds south of the White House. 
 
 %he IQashmgl'on TDonumenl'. 
 
 The Washington Monument stands on the bank of the Potomac river south of 
 the While House, very near the spot designated by Major L'Knfant in the original 
 plan of the city for an equestrian statue to the memory of Washington. It is also very 
 near the centre of the original District of Columbia. 
 
 The designer of the Monument was Robert Mills, of South Carolina. Its erec- 
 tion was begun in 1847, but was interrupted in 1855, when it had reached a height of 
 152 feet, through failure of funds, which had thus far been contributed by private in- 
 dividuals. Work was resumed in 1878 under appropriations made by Congress. The 
 capstone was put in place December 6, 1884, and the dedication took place on Feb- 
 ruary 21, 1885, with imposing Masonic ceremonies. Robert C. Winthrop, of Massa- 
 chusetts, was the orator both at the laying of the cornerstone and at the dedication. 
 The total cost of the Monument has been $1,200,000, of which $300,000 was raised by 
 contributions from the people. 
 
 The shaft is of Vermont marble. Its original foundation was 80 feet square at 
 the base^ 55 feet square at the top and 25 feet high, 17 feet above the surface. 
 When work was resumed in 1878 it was found advisable to enlarge the foundation, and 
 a mass of concrete i26>2 feet square and i3>4 feet in thickness was placed under the 
 original foundation, a noteworthy feat of engineering. The engineer in charge of the 
 work from 1878 to the completion of the Monument was Col. (now Gen.) Thomas h. 
 Casey. 
 
 The Monument is 555 feet in height, 55 feet square at the base, and 31 }4 feet 
 square at the base of the summit pyramid, which is 55 feet high. The apex of the 
 pyramid is a solid block of aluminum 9 inches high, 4>2 inches square at the base and 
 weighing 6}( pounds. The total weight of the Monument is 80,000 tons. At the 
 time of its completion this shaft was the highest building in the world. It is now 
 (i8gi) surpassed only by the Eiffel Tower in Paris. 
 
 By means of an elevator one can ascend to a landing at the base of the summit 
 pyramid, and through port holes obtain magnificent views of the city and surrounding 
 country. By walking down the iron staircase one can see the numerous memorial 
 tablets set in the walls, contributed by various nations, states, cities, societies, cor- 
 porations and individuals. 
 
 7 
 
The elevator ascends at the even hour and half hour. The Monument is open 
 every week day from g a. m. to 5.30 p. m. 
 
 "^he (Sopeopan Tivi! Qallep'^. 
 
 Situated on Pennsylvania avenue, corner of Seventeenth street, opposite the 
 State, War and Navy Departments. This Gallery was founded and endowed by W, W. 
 Corcoran, a citizen of Washington. The present building was erected in 1859. The 
 two bronze lions at the main entrance are copies of Cantora's at the tomb of Pope 
 Clement XIII. It has one of the best collections of paintings in this country, and is 
 constantly being enriched by purchase. Connected with the Gallery is a school of art. 
 Unfortunately the Gallery is closed for repairs during August. 
 
Tlhz 'Departments and Zeienhfie lnzhK\honz. 
 
 jSuilding of the State, IQar ai^d T}aT?2 'Departments. 
 
 This massive structure stands on the south side of Pennsylvania avenue just 
 west of the White House. It is built in Italian Renaissance style, and was begun in 
 187 1 and completed in 1887, from designs by Mr. A. B. Mullett, late supervi.sing arch- 
 itect of the Treasury. The stone is granite, from Maine and Virginia. The State De- 
 partment occupies the southern portion of the building ; the War Department the 
 northern and western, and the Navy Department the eastern wing. Many of the rooms 
 are richly frescoed and decorated, and contain numerous portraits, historical relics and 
 other objects of interest. 
 
 State Department. 
 
 Honorable James G. Blaine, Secretary of vState. 
 
 The Department is open from 9 a. m. to 2 p. m. On the third ffcor is an excel- 
 lent library for the purposes of the Department. The original Declaration of Inde- 
 pendence is exhibited in the library with other historical documents, many of them 
 relating to the earl}' days of the country. 
 
 Tdap Department. 
 
 Honorable RedfieIvD ProcTOR, Secretary of War. 
 
 Man}' of the rooms and corridors are adorned with portraits of distinguished 
 generals, most of which may be seen by applying to the messenger at the Secretary's 
 door. 
 
 Headquarters of tJie Army. Major-General John M. Schofield, Commanding. 
 The office is located in the north wing at the east end of the corridor. 
 
 Corps of Engineers. Brigadier-General Thomas I^. Casey, Chief of Engineers. 
 The Corps of Engineers are charged with all duties relating to fortifications; with tor- 
 pedoes for coast defen.ses ; with all military bridges ; and such services as may be re- 
 quired for these objects. It is also charged with the harbor and river improvements. 
 
Ordnance Bureau. Briji^adier-Geiieral D. W. Flagler, Chief of Ordnance. The 
 Bureau of Ordnance has charge of all the national armories, gun factories, arsenals and 
 ordnance depots, and is expending large sums of money in the manufacture of 
 modern guns. 
 
 %hz T^rrn]? TDedieal TDuscum ai^d liibparg. 
 
 The Arni}' Medical Museum occupies a portion of the new building erected at 
 the northwest corner of Seventh and B streets southwest, east of the National Museum. 
 The rest of the building is occupied b}- the Library of the Surgeon-General's Office, a 
 portion of the Record and Pension Division of the War Department, and the L,aboratory. 
 The Museum was removed in 1887 from the building formerly known as Ford's 
 Theater (Nos. 509 and 511 Tenth street northwest.) 
 
 The Mu.seum was founded and a large portion of the medical and surgical speci- 
 mens collected during the war of the rebellion. Since the close of the war, however, 
 the officers in charge have continued to collect specimens from the medical officers of 
 the army at the several military posts, and a number of valuable specimens have been 
 contributed by physicians engaged in private practice. 
 
 At the close of the fiscal year terminating June 30, 1891, the Museum contained 
 about 10,135 pathological specimens, 3,314 anatomical specimens, 11,500 microscopical 
 specimens, and 1,717 .specimens of comparative anatomy. It was visited last year by 
 more than 42,000 persons. 
 
 This collection is richer in specimens illustrative of the results of gun-shot 
 wounds, and of the surgical operations which they necessitate than any other collection 
 in the world. In other departments, though it does not equal some of the wealthy and 
 long established museums of Europe, its collections are, nevertheless, by far the most 
 important in America, and are annually increasing in extent and value. 
 
 The Library of the Surgeon-General's Office, which occupies a portion of the 
 same building, is the largest and most valuable medical library in the world. At the 
 close of the fiscal year terminating June 30, 1891, it contained about 100,000 books and 
 150,000 pamphlets, and the number is steadily increasing. Medical men from any part 
 of the country desirous of consulting the works in this library are courteously welcomed 
 and granted free access. 
 
 Both the Museum and Library are open to visitors daily, except Sundays, from 
 9 a. m. to 4 p. m. The Seventh-street Cable Road, which connects with the principal 
 street railroads, carries visitors direct to the Museum. 
 
 10 
 
lla-c^ 'Dcparlrncnl'. 
 
 Honorable Benjamin F. Tracy, Secretary of the Navy. 
 
 The Chiefs of the Bureaus of the Nav,v Department are officers of the United 
 vStates Navy and part of the Naval estabHshnient. Upon the walls of the vSecretary's 
 office are hung some excellent portraits of former secretaries ; in the corridors are to be 
 seen some fine models of the new cruisers. The Library is on the fourth floor. 
 
 TJa-^al ©bser'^pal'OP'^- 
 
 Captain S. V. McNair, U. S. N., Superintendent. 
 
 The Observatory is situated on the corner of Twenty-fourth and D streets North- 
 west. It was established in 1S42, its object being to promote the ends of navigation. 
 The Observatory is equipped with a 26-inch equatorial mural circle and transit and 
 a prime transit for declinations, and many other notable instruments. Astronomical 
 observations are made in order to establish and correct the data used by the navigator, 
 and all the instruments connected with navigation are tested in this office. Connected 
 with the Observatory is a corps of astronomers of national reputation. The results 
 of the investigations are published annually under the title of ' ' Washington Observa- 
 tions." The Observatory is open to the public on all work-days from 9 a. m. to 4 p. m. 
 . A • new observatory is being built one mile north of Georgetown, but it is not yet 
 ready for occupancy. It has an excellent position, admirably chosen for its purposes. 
 The grounds surrounding the building embraces about 60 acres. 
 
 llauheal T^lmanae. 
 
 Prof. Simon Newcomb, U. S. N., Superintendent. 
 
 The Nautical Almanac Office is situated at the northwest corner of Pennsylvania 
 avenue and Nineteenth street ; entrance. No. 810 Nineteenth street. A regular staff 
 of ten assistants is employed in this office. 
 
 f The American Ephemeris and Nautical Almanac. 
 The American Nautical Almanac. 
 Annual Publications : <| ^^^ ^^^^^^.^ Coasters Nautical Almanac. 
 
 I The Pacific Coasters Nautical Almanac. 
 
 Publicafions^ issued at ( Astronomical Papers of The American Ephemeris. 
 irresutar intervals : { 
 
 II 
 
"U, Z. H^dpographie Offiec. 
 
 Lieutenant-Commander Richardson Clover, U. S. N., Hydrographer. 
 
 A branch of the Bureau of Navigation, Navy Department. Offices in the 
 Department building, basement, east front. 
 
 Work consists essentially in the supplying to vessels of war and the merchant- 
 marine of charts, sailing directions, light lists, publications relating to marine meteor- 
 ology, and other information. The object of the office is to secure the earliest possible 
 reliable information from all sources and to put it promptly before those especially 
 interested in navigation. 
 
 Branch offices are established in nine of the principal ports of the United States ; 
 each of these is in the charge of a naval officer, with one or more assistants. In this 
 way information is readily collected and promptly circulated. 
 
 The Office is divided into the following divisions : 
 
 First. — Chart Construction. In charge of the actual engraving of charts. Here 
 can be seen everj- step in the process, from the time the working sheets are received 
 from the surveying vessels until the final chart is printed from the copperplate. 
 Abottt 60 new nautical chart-plates are produced every year, and about 30,000 charts 
 are printed from copperplates. 
 
 Second. — Issue and Supply. In charge of the issuing and supplying of charts 
 to naval and other vessels. A supply of every chart likely to be required is kept on 
 hand. Including lithographed charts, the office itself issues 863 different charts, about 
 10,000 copies being sold per year and 7,000 issued to U. S. Naval vessels. 
 
 Third. — Sailing Directions. This division has general charge of the archives of 
 the office (where all original data are kept, copies of every chart ever issued by any 
 office and now in actual use, and a copy of every chart ever issued by the Hydrographic 
 Office) ; the preparation and publication of .sailing directions for various oceans ; the 
 publication and correction of the six volumes of light lists (lists of light-houses) ; and 
 the weekly Notices to Marines, a pamphlet containing mention of all corrections and 
 changes in charts and other publications (circulation about 1,000 copies per week, not 
 counting the reprints of various paragraphs). 
 
 Fourth. — Marine Meteorology. In charge of the general subject of climate, 
 weather, storms, currents, best sailing and steam routes, etc. The monthly Pilot 
 Chart of the North Atlantic Ocean, the "weekly Hydrographic Bulletin, and occasional 
 treatises on storms of various oceans are prepared and publi.shed by this division, which 
 has a corps of about 1,000 voluntary observers who take daily observations and send 
 in their reports from every port. The Pilot Chart has a monthly circulation of 3,300 
 copies, and is supplied free to the voluntary observers in return for their observations. 
 It contains a forecast for the month succeeding the day of issue and a review of the 
 
 12 
 
precediiii; month, showing graphically the direction and force of prevailing winds, the 
 tracks of storms, positions and tracks of derelict vessels, ice, buoys, and other obstruc- 
 tions to navigation. 
 
 -pi[ih.—A/ai//ni>- Division. This has charge of the correspondence with the 
 In-anch ofRces and the mailing of all publications. 
 
 'U. 5. Tl^v^ yapd. 
 
 Commodore J. vS. vSkerrETT, U. vS. N., Coiiunandant. 
 
 The Navy Yard is situated on the Anacostia river, southeast of the Capitol. 
 It is reached by the Washington and Georgetown Railroad in cars marked "Navy 
 Yard"; time from Lafayette Square to the Navy Yard, about 35 minutes. It was 
 formerly a ship-yard and many famous vessels were built there. It is now entirely de- 
 voted to the construction of modern ordnance, and its various shops are amply equipped 
 with the l)est modern machinery for the manufticture of large guns. There is a 
 museum of interesting articles in the Yard. The Navy Yard is open to visitors from 
 7 a. m. initil sundown. 
 
 U. S. TDanne !Bai'paeks. 
 
 The Marine Barracks is the long row of buildings on the ground facing Eighth 
 street, two squares north of the Navy Yard. In the armory on the south side are 
 found some interesting old relics. 
 
 "Q^reasup-g "DepaplTncnl?. 
 
 Honorable CharIvES Foster, vSecretary. 
 
 The Treasury Department stands on Fifteenth street, east of the White House. 
 This building, of Grecian Ionic style of architecture, is, like the Capitol, the result of 
 extensions of the original plan. Mr. Thomas U. Walter w^as in both cases the archi- 
 tect of the extensions, and produced a very harmonious effect. The old part of the 
 building fronts on Fifteenth street, while the extensions form the northern, western 
 and southern fronts. The original portion of the building is of Virginia sandstone, 
 while the stone employed in the extensions is granite from Dix Island, Maine. 
 
 Any one visiting the Treasury should not fail to examine the columns of the 
 new portions, as they are monoliths, 31 feet high and nearly 4 feet in diameter. The 
 main objects of interest are the United States Treasury or Cash Room, the Vaults, and 
 the Secret Service Bureau. The Ca.sh Room is ornamented with beautiful marbles 
 from various places. Open to visitors from 9 a. m. to 2 p. m. A guide is sent with 
 visitors to all places open to the public. 
 
 13 
 
Xlnil'cd Zio.tcz Tflint. 
 
 Dr. R. O. Leech, Director. 
 
 The Office of the Director of the Mint is in the Treasnry Building. The 
 Director has general supervision of all mints and assay offices, the purchase of 
 silver bullion, and the allotment of its coinage. Two annual reports are published, 
 one upon the operations of the mints and assay offices, and a second upon the 
 statistics of the production of the precious metals in the United States. The report 
 for the calendar year 1890 bears the date of February 26, 1891. 
 
 United States Coast and Qeodetie Zuvve^ ^^nd ©ffiee of Standard 
 
 TCLeights and TlQeasures. 
 
 Dr. T. C. Mendenhall, vSuperintendent. 
 
 The Coast and Geodetic Survey is a bureau under the Treasury Department. 
 Its work, begun in 1S17, was almcst immediately stopped by legislation, but 
 was resumed in 1832 under the direction of Hassler, its first superintendent. He 
 was succeeded b}' Bache, under whom the Survey reached a fuller development on the 
 plans proposed by his predecessor. 
 
 Its objects are primarily to make surveys of the coast and the adjacent waters, 
 and to collocate these surveys by extended trigonometric operations along the coasts 
 and across the interior. It is also charged bj^ law with the duty of furnishing trigono- 
 metric pQints to the several States. 
 
 The extent of the surveyed and unsurveyed shore line is estimated at about 
 145,000 kilometers. 
 
 In addition to its mensurational work, which is of the highest degre^ of 
 precision, the Survey conducts pendulum observations, tidal researches and a general 
 magnetic survey of the whole territory of the United States. The office of the U. S. 
 Standard of Weights and Measures is also under the direction of the Superintendent, 
 and furnishes standards to the several States and verifies weights and measures. 
 
 The publications of the Survey are : 
 
 A7i7iual Reports, .showing progress and containing professional papers. 
 
 Charts on various scales, covering the coast line, for the use of navigators. 
 
 Coast Pilot, a series of volumes giving minute descriptions of the coast, with 
 sailing directions. 
 
 Tide Tables, giving the predicted tides at the chief ports of the United States. 
 
 Professional and scientific papers, published separately from the aiuiual reports, 
 but also contained in them. 
 
 Bulletins, giving early results of work accomplished. 
 
 14 
 
Noliirs to Mariners, giving new data in rc^iird to published charts. 
 
 The Charts, Tide Tallies and Coast Pihn can be p urchased at the Coast and 
 Geodetic Survey Office, or at agencies existing in the principal seaport towns, at 
 about the cost of paper and printing. 
 
 The other publications are for gratuitous distribution. 
 
 The office is located on New Jersey avenue, near B street southeast, just south 
 of the Capitol. 
 
 Bureau of "Engpa^^ing ai^d IPpii^ting. 
 
 WlLLlAiM M. MiCRKDiTH, Chief of Bureau. 
 
 This Bureau occupies a large brick building situated on the corner of Fourteenlli 
 and B streets southwest, a .short distance from the Department of Agriculture. Here are 
 engraved and printed all the United States bonds, the paper money of the Government, 
 and the internal revenue stamps. It is regarded as one of the most interesting l)ureaus 
 to the general visitor. A competent guide is furnished upon application to the Sui:)er- 
 iutendent of the building. Open to visitors from 9 a. m. to 2 p. m. 
 
 T)epapl'menl' of the Inizviov. 
 
 Honorable John W. Noblk, Secretary. 
 
 This department building occupies the block bounded by F and G and Seventh 
 and Ninth streets northwest, with the main entrance on F street. It is a massive white 
 structure of imposing appearance ; the centre is built of sandstone and the wings of 
 white marble, resting upon a basement of granite. Under this department are gathered 
 a large number of bureaus : the Patent Office, the Pension Office, General Land Office, 
 Office of Indian Affairs, Bureau of E^ducation, Commissioner of Railroads, U. S. 
 Geological vSurvej', and U. S. Census. 
 
 United Zicktzz Geologieal Zmvvz^- 
 
 Major J. W. PowELL, Director. 
 
 The Geological Survey is a bureau of the Department of the Interior. It was 
 establi.shed by Act of Congress, March 3, 1879, the objects as provided for in the Act 
 being the " classification of public lands and examination of the geological structure, 
 mineral resources and products of the National domain." The President appointed 
 Hon. Clarence King as first Director of the Survey. In March, 1881, Mr. King 
 retired from the directorship and was succeeded by Maj. J. W. Powell, under whose 
 guidance the work of the Survey has developed to its present large proportions. 
 
 15 
 
On nccounl of tlic extent and diversity of its operations this work is at present 
 carried on 1)\ a nnniher of coiMdinalc divisions enibracini; nearly every department of 
 geolo.i;y and paleonlolo!;\-, willi wliieli are associated laboratories for the investij^ation 
 of chemical and ])liysical prol)leins directly related to ideology. The preparation of a 
 tojio^raiihical map, to serve as a basis npon which the K<^'ological features of the 
 country are liiially In \k- laid down, is carried on in the Division of Geography, with 
 which is connected a large force of topographical engineers and a corps of expert litho- 
 graphers. There is a Division of Mining vStatistics and Technology engaged in prepar- 
 ing annual reports, showing for each calendar year the mineral jiroducts of the country. 
 There is also a Division of Tlhistration. with which is connected a complete photo- 
 graphic lal)orator\- for the reproduction of negatives taken in the field, and copy- 
 ing n\aps and drawings. The (Geological Sinvey Library contains nearly -^0,000 
 volumes, 42. 000 pamphlets, and over 22,000 maps. The di.stribulion of the Survey 
 publications is in charge of the Librarian. 
 
 The oflicc of the Geological Sni \ey is located in the Hooe Building, No. 1330 
 I'" street northwest, where the greater part of the geological and topographical work is 
 elaborated, the field explorations being con(ln(k<l during the season in all portions of 
 the United States. The paleontological collections and workshops are loca'ed either 
 in tlie vSmithsonian Institution or in the U. S. National Museum ; in the latter are also 
 the chemical and physical lalioratorics. There are branch offices and laboratories of 
 the Survey in various portions of the country, where special work is being carried on 
 b>- persons connected with universities and colleges. These form a very considerable 
 portion of the scientific force. 
 
 The publications of the Survey are : 
 
 Annual Reports. By the Director to the vSecretary of the Interior, ])re.senting a 
 summary of the plans and ojierations of the Survey, accompanied by short adminis- 
 trative reports from chiefs ol divisions, followed by a number of scientific papers of 
 general interest. 
 
 Monofi;raphs. Quarto volumes, containing the more important and elaborate 
 publications of the Survey. Seventeen monograi)hs have been published. 
 
 BuUciins. Each of these contains but one paper and is complete in it.self. 
 They are, for the most part, short articles giving the more important results of an 
 investigation, and do not inoperly come under the head of Annual Reports or Mono- 
 graphs. Sevent\-nine luilklins have been pnl>lished. 
 
 Annual Kcpotis upon the Hfincfal Resources of the Uniied States 
 
 The Annual Reports are for gratuitous distribution. Monographs and Bulletins 
 are sold at about the cost of pul»lication. A limilrd mimlKM- of the Mineral Resources 
 are for gratuitous distribution. 
 
 For a detailed account of the general plan and scope of the Survey and its 
 methods of work, see the ICighth Annual Rcjiort of the Dirci^tor for the year iSvSG-S;. 
 
 16 
 
U. Z. raJenl- ©ffiee. 
 
 Honorable W. K. vSimonhs, Coiiimissioiicr. 
 
 The Patent Ofiice was organized in its ])rcsent form in 1X36. It occupies cer- 
 tain portions of the main building on F street. As an object of interest to visitors its 
 ])rincipal features arc the simple massive architecture of the Iniilding itself, and the 
 Model Room in the top story, where models of all patented inventions capable of being 
 thus represented are arranged in cases, classified by subjects. The organization includes 
 an Examining Corps with thirty-two divisions, the la.st two having been added 
 recently on account of the great expansion of the work ; the Issue and Gazette, 
 Drafting, As.signment, or copying divisions, and the vScientific Library. This 
 library may be of .somewhat especial interest to scientific men. It aims to embody, 
 as far as conditions admit, the whole literature of human industry, according to 
 its main purpo.se of assistance to the examiners in their researches. It is a repository 
 of applied, rather than of pure science. It contains about 50,000 volumes, including 
 pamphlets, and is much used by the patent profession and by branches of the Govern- 
 ment doing .scientific work. 
 
 U. Z. TJureau of 'Edueal'ion. 
 
 William T. Harris, IJ.. I)., Commissioner. 
 
 This Bureau is situated at the northwest corner of Eighth and G streets north- 
 west. Its functions will be best understood when it is remembered that the Federal 
 Government of the United States does not support or control the schools and colleges 
 of the country. Each State has full jurisdiction over the subject of education, and the 
 public schools are State institutions, subject entirely to State laws. The Bureau of Ed- 
 ucation is an agency with the especial function of increasing the enlightened directive 
 power of the people with regard to their schools. This function is performed by the 
 publication of annual and special reports, and occasional bulletins and circulars of in- 
 formation upon educational questions. 
 
 The material for these reports is collected by extensive correspondence with 
 the officials in charge of State, city and county public school .sy.stems, with the presi- 
 dents and principals of universities, colleges, seminaries, high .schools, and other sec- 
 ondary schools, and with the ministers of education of foreign countries and officers 
 and professors of foreign in.stitutions of learning. 
 
 The Library of the Bureau contains 17,500 bound volumes, including all im- 
 portant pedagogical works, and 100,000 pamphlets. 
 
 17 
 
'U. Z. Census. 
 
 Houorable Robert P. Portkr, Superinteiulent. 
 
 The Census Office is established by act of Congress every ten years. During 
 its short term it employs thousands of clerks, besides enumerators and special agents in 
 all parts of the United States. The executive office is at the corner of Third and G 
 streets northwest. The count of the population for the year 1890 was made at the 
 Inter-Ocean Building on Ninth street, between E and F streets northwest. In this 
 work the ingenious electric counting machines invented bv Dr. Hollerith were used 
 and may be seen in operation, together with the electric classifying sy.stem. The 
 results thus far published are in the form of bulletins, eighty-four of which have ])een 
 issued. Copies of most of these can l^e ol^tained by application at the executive office. 
 
 Pension Bureau, 
 
 Honorable GreEN B. Raum, Commissioner. 
 
 The administration of the enormous business of the Pension Office requires a 
 large building. It stands by itself in Judiciary Square, between Fourth and Fifth and 
 F and G streets northwest. It is an imposing edifice, constructed entirely of red brick 
 ornamented with terra cotta. The inauguration balls of March 4, 1SS5, and March 4, 
 18S9, were given in the central hall. 
 
 'Depapl'ment' of T^gneulture. 
 
 Honorable J. M. RuSK, Secretar}'. 
 
 (Kslablishcd by an .\ct of Congress, February 9, 1S89). 
 
 • 
 
 The Secretary of x\griculture is charged with the supervision of all public 
 business relating to the agricultural industry of the country. He exercises advisory 
 supervision over the agricultural experiment stations deriving support from the National 
 Treasury, and has control of the quarantine stations for imported and domestic cattle. 
 
 The Assistant Secretary has general control and direction of a large number 
 of scientific divisions in charge of specialists, whose duties may be concisely expressed 
 as follows : 
 
 The Statistician collects all information as to the principal crops and farm animals, 
 and obtains similar information from European countries. He publishes a monthly 
 bulletin of the statistics of the agricultural production, distribution and consumption. 
 
 The iMitomologist obtains and dis.seminates information regarding insects, and 
 appropriate remedies for their extirpation. 
 
 18 
 
The Botanist investigates platils and grasses of agricultural value or of injurious 
 character, and answers inquiries relating to the same, and has charge of the Herbarium. 
 
 The Chemist makes analyses of natural fertilizers, vegetable products and other 
 materials which pertain to the interests of agriculture. 
 
 The Ornithologist investigates the economic relations of birds and mammals, and 
 recommends measures for the preservation of those species beneficial to crops and the 
 destruction of injurious species. 
 
 The Director of the Office of Experiment Stations secures, as far as practicable, 
 uniformity of methods in the work of the stations throughout the country. He also 
 compiles and publishes such of the results of the station experiments as may be deemed 
 necessary. 
 
 The Chief of the Bureau of Animal Industry investigates the existence of 
 dangerous contagious disea.ses of live stock, superintends the measures for their extir- 
 pation, and makes original investigations as to the nature and prevention of such 
 diseases ; has charge of the quarantine stations for cattle, and reports on the animal 
 industries of the country. 
 
 The Pomologist collects and distributes information in regard *to the fruit 
 industry of the United States and the best means for its improvement. 
 
 The Chief of the Division of Vegetable Pathology investigates the diseases of 
 plants, and seeks to determine remedies for their mitigation and prevention. 
 
 The Chief of the Division of Forestry is occupied with experiments and reports 
 regarding forestry ; with the distribution of seeds of valuable economic trees, and with 
 the dissemination of information upon forestry matters. 
 
 The Microscopist makes investigations relating to parasitic growths ; to the 
 characteristics of fibres, and to the adulteration of foods. 
 
 The Seed Division collects new and valuable seeds and jilants for propagation 
 in this country and distributes them to applicants, who are required to furnish the 
 department with a report as to results obtained with seeds so furnished them. 
 
 The publications of the Department of Agriculture consists of an 
 Annual Report. 
 
 Special Reports on various subjects, published from time to time. 
 
 Bulletins b}- the Divisions of 
 
 Botany, Chemistry, Statistics, Entomology, Forestry, Pomology and Experiment 
 Stations. 
 
 Periodical Bulletins entitled : 
 
 "Insect Eife," "North American Fauna," "Journal of Mycolog}'," and " Con- 
 tributions from the U. S. National Herbarium." 
 
 19 
 
%lm tQeathep ^Bureau. 
 
 Professor Mark W. Harrington, Chief. 
 
 The Weather Bureau, which was transferred to the Department of Agriculture 
 on July I, 1891, has its office at the corner of Twenty-fourth and M streets northwest, 
 innnediately adjoining the grounds of the Columbia Hospital. 
 
 The Library, under the management of Mr. O. L. Fassig, containing 11,000 
 volumes and 3,000 pamphlets ; the Instrument Room, under Professor C. F. Marvin, 
 and the Indications Room will be found interesting to visitors. 
 
 The observations made daily at 8 a. m. are displayed on a printed map with 
 accompanying predictions for the next thirty-six hours, and will be furnished by 1 1 
 a. m. daily for the use of the American Association, the Geological Society of America, 
 and the International Congress of Geologists. 
 
 IPost-^ffiee 'Departmci}!'. 
 
 Honorable John Wanamaker, Postmaster-General. 
 
 This department occupies a massive structure opposite the Department of the 
 Interior. It covers an entire square bounded by E and F and Seventh and Eighth 
 streets. It is built of white marble. The main feature of interest is the dead-letter 
 office, to visit which a pass from the Chief Clerk is necessary. 
 
 T)epar-l'mei2l' of ^uzl'iee. 
 
 Honorable William H. H. MillER, Attorney-General. 
 
 This department is situated on Pennsylvania avenue, between Fifteenth street 
 and Lafayette Square. It is four stories high and built of Potomac Seneca redstone. 
 The office of the Attorney-General contains a gallery of portraits of all the Attorneys- 
 General of the United States since the foundation of the government. The Court of 
 Claims occupies the first floor of the building. 
 
 %lm Zmithzonidin Inzhl'uhoij. 
 
 Professor S. P. Langley, Secretary. 
 
 The Smithsonian Institution is supported b}^ a permanent fund at present 
 amounting to $703,000, the accumulations of a bequest to the United States made in 
 1826 by James Smithson, a scienti.st of England, " to found at Wa.shington under the 
 
 20 
 
name of Uie vSmithsoiiiaii Inslilution an cstal.lishiuent for the increase and diffusion of 
 knowledge among men." Some years were occupied in securing the bequest and in 
 perfecting plans for carrying out its provisions. By Act of Congress, August lo, 
 1846, the Institution was created as an "Establishment," of which the President and 
 the other principal officers of the general government were made ex-officio members, 
 while the direction of affairs was intrusted to a Board of Regents "to be composed of 
 the Vice-President, the Chief Justice of the Supreme Court, (the Mayor of Washing- 
 ton), three members of the Senate, and three members of the House of Representa- 
 tives', together with six other persons other than members of Congress, two of whom 
 shall be resident in the City of Washington, and the other four shall be inhabitants of 
 some state, but no two of the same state." 
 
 The plan of organization adopted contains the following propositions : 
 
 "I. To increase knowledge. It is proposed to stimulate men of talent to make 
 original researches by offering suitable rew^^rds for memoirs containing new truths. 
 
 "II. To increase knowledge. It is also proposed to appropriate a portion of 
 the income annually to special objects of research under the direction of suitable per- 
 sons. 
 
 "III. To diffuse knowledge. It is proposed to publish a series of periodical 
 reports giving an account of the progress of the different branches of knowledge. 
 
 "IV. To diffuse knowledge. It is proposed to publish occasionally separate 
 treatises on subjects of general interest." 
 
 A further part of the plan contemplated the formation of a Library, a Museum 
 
 and a Gallery of Art. 
 
 While the developments of the past forty-five years have been greater in some 
 directions than in others, the original plan has been consistently followed with highly 
 gratifying results. 
 
 The chief administrative ofiEicer of the Institution is the Secretary, a position 
 which has been occupied by only three persons, namely, Joseph Henry, Spencer F. 
 Baird and Samuel P. Langley. The Assistant Secretary is the officer in charge of the 
 National Museum. 
 
 The Smithsonian Building is situated in that division of the Mall, between 
 Seventh and Twelfth streets, known as Smithsonian Park. It was built, 1847-1856, 
 at a cost of $450,000, after designs by Renwick. The style is termed " Norman " or 
 " Romanesque," and the material is a lilac-gray freestone, found in the red sand- 
 . stone formation about twenty-three miles above Washington. The building contains 
 at present the administrative offices, reading room, the exchange deparcment, and 
 ■ several collections of the National Museum, notably those of birds, shells and archaeo- 
 logical specimens. 
 
 The Library of the Smithsonian Institution consists of more than 250,000 
 volumes and parts of volumes. It is for the most part deposited in the Congressional 
 
 21 
 
Library, but each department of the Institution and the National Museum is supplied 
 with such books as relate to its special work. The collection of the publications of 
 scientific societies and of scientific periodicals is very large. 
 
 The Smithsonian Bureau of International Exchanges, which was early insti- 
 tuted, has accomplished a great work in distributing in this country and abroad the 
 government publications, and the publications of scientific and literary societies of 
 almost every country in the world. By its agency the Smithsonian Library has been 
 enriched with many rare works of reference, and the publications of the Institution 
 have been scattered far and wide. The general government has now assumed the 
 support of this Bureau, and has made the Institution its agent in distributing all 
 government scientific publications to foreign countries. An idea of the magnitude of 
 the work may be formed from the statement that more than 90,000 packages, repre- 
 senting over 100 tons of books, pass through the Bureau each year. Over 16,000 
 correspondents, societies and individuals, are upon the exchange list. 
 
 The Smithsonian Institution is charged by Congress with the expenditure of 
 the sums annually appropriated for the Bureau of International Exchanges, the Bureau 
 of Ethnology, the National Museum, and the National Zoological Park. 
 
 Publications. — The Smithsonian Institution has three classes of publications : 
 
 First — "Contributions to Knowledge," a quarto series, in which are included 
 memoirs giving new facts obtained in original research. 
 
 Second — "Miscellaneous Collections," an octavo series, containing practical 
 papers or treatises, such as systematic lists of species in the animal, vegetable or 
 mineral kingdoms, tables of natural constants, scientific bibliographies, and other 
 summaries. 
 
 Third — "Annual Reports," an octavo series, containing the yearly report of the 
 Secretary to Congress of work done, and supplemented by short papers upon the most 
 important scientific discoveries of the year, by bibliographies of current literature, and 
 by accounts of progress in various sciences. 
 
 In the Park near the northwestern corner of the building is a bronze statue to 
 the memory of Joseph Henry, the first Secretary, to whose wise guidance the Institu- 
 tion owes a large share of its prosperity. 
 
 %hz llaMonal TDuscum. 
 
 G. Brown Goode, Assistant Secretary. 
 
 The National Museum is maintained by annual Congressional appropriations 
 which are expended under the direction of the Smithsonian Institution, and the Assistant 
 Secretary- of the latter is in charge of the Museum. The Museum originated in 1840, 
 when the National Institution was organized, and the collection of the Wilkes expe- 
 dition constituted its nucleus. In 1849 a museum was established b}^ the Smithsonian 
 
 22 
 
Institution, and this, in 1S58, was made the repository of all the scientific collections 
 of the government, including those of the National Institution. It acquired very large 
 collections from various sources at the close of the Centennial lixposition, in 1S76, and 
 from that time has been recognized as the National Museum of the United States. 
 The large accessions in 1876 led to the erection of the present museum building (1879- 
 1881), but the additions since its occupation are sufficient to fill a much larger building 
 than the present one. Out of thirty-three departments and sections there are seven to 
 which no room for exhibition purposes can be assigned in the Museum building for lack 
 of space. To some of these departments, however, have been allotted inadequate ac- 
 commodations in the Smithsonian building. 
 
 No official guide to the collections has yet been published, although the curators 
 of several of the departments have prepared hand-books descriptive of the collections 
 under their charge. On the right, at the entrance to the Museum, is a bureau of in- 
 formation for the guidance of visitors. 
 
 The following is a list of the Scientific Departments in the Museum : 
 fArts and Industries || : G. Brown Goodc,* Assistant Secretary, acting as 
 
 curator. 
 fEthnology : Otis T. Mason, curator. 
 
 t American Aboriginal Pottery : Wm. H. Holmes,* curator. 
 X Prehistoric Anthropology : Thomas Wilson, curator. 
 t Mammals : F. W. True, curator. 
 I Birds : Robert Ridgway, curator. 
 :|: Birds' Eggs: Capt. Charles E. Bendire,* curator. 
 
 Reptiles : Dr. Eeonhard Stejneger, curator, 
 t Fishes : Tarleton H. Bean,* curator, 
 t Vertebrate Fossils: O. C. Marsh,* curator. 
 
 iMollusks: W. H. Dall,* curator. R. E. C. Stearns, adjunct curator. 
 t Insects : C. V. Riley,* curator. 
 
 Marine Invertebrates : Richard Rathbun,* curator, 
 t Comparative Anatomy : Frank Baker,* curator. 
 t Invertebrate Fossils : 
 
 Paleozoic — C. D. Walcott,* curator. 
 
 Mesozoic — C. A. White,* curator. 
 
 Cenozoic — W. H. Dall,* curator. 
 t Fo.ssil Plants : Lester F. Ward,* curator. 
 
 § Botany : Dr. George Vasey,* curator, Botanist of the Department of Agri- 
 culture. 
 t Minerals : F. W. Clarke,* curator. 
 t Geology : George P. Merrill, curator. 
 
 I. 
 
 II. 
 
 III. 
 
 IV. 
 
 V. 
 
 VI. 
 
 VII. 
 
 VIII. 
 
 IX. 
 
 X. 
 
 XI. 
 
 XII. 
 
 XIII. 
 
 XIV. 
 XV. 
 
 XVI. 
 XVII. 
 
 II This department at the present time includes twelve different sections, each of which is under 
 the charge of a curator, or an assistant acting as a curator. 
 
 * Honorary. 
 
 t Departments with cxliil^ts in the Museum building. 
 
 X Departments with exhihits in the Smithsonian building. 
 
 ■iiThe National Herbarium is for the present kept in the building of the Department of Agri- 
 culture. 
 
 23 
 
For information regarding the general collections of the National Museum the 
 visitor is referred to a guide : "The Smithsonian, the National Museum and the Zoo," 
 to be purchased (25c.) in the rotunda of the Museum. This book is not an official 
 ]ni])lication. For the geological collections, the arrangement of which has recently 
 been changed, the visitor should secure the preliminary hand-book of the department 
 of geology by the curator, G. P. Merrill. The Geological Department embraces both 
 economic and general geology. In the Mineralogical Hall are the systematic mineral 
 collection, a collection of gems and precious stones and one of meteorites. 
 
 The pu))lications of the National Museum embrace the "Proceedings," the 
 " Bulletins" and the "Annual Report," which forms the second volume of the Smith- 
 sonian Report, and whose appendix contains many scientific papers. 
 
 ^Bureau of 'El'hnolog^- 
 
 Major J. W. Powkll, Director. 
 
 The Bureau of Ethnology was organized in 1S79, and was placed under the 
 direction of Major J. W. Powell, Director of the Geological Survey. In its early years 
 it was so closely associated with the Geological Survey that its work was and still is 
 often confounded with the work of that Bureau. It is, however, a separate and distinct 
 organization supported by specific appropriations made by the general government, and 
 the general supervision of its scientific work is confided to the Secretary of the Smith- 
 sonian Institution. The appropriation for the current year is $50,000. 
 
 The work of the Bureau comprises the whole field of North American 
 Ethnology, including Archaeology ; and the range of its work extends from Alaska 
 on the north to Panama and the Isthmus of Darien on the south. Its collections are 
 deposited in the National Museum, and those branches of Indian art to which it has 
 especially devoted attention are now illustrated by collections of specimens which 
 compare favorably with those of the largest museums. Its collection of aboriginal 
 American Pottery, now in the National Museum, is notably the largest and finest in 
 existence. 
 
 The publications of the Bureau comprise Annual Reports, to which are 
 appended papers upon subjects of general interest, a series of Bulletins, consisting of 
 reports upon .special subjects, and Quarto Contributions to North American Ethnology. 
 These publications are distributed through the exchange system of the Smithsonian 
 Institution. 
 
 The office of Major Powell is in the Geological vSurvey Building, No. 1330 F 
 street northwest. 
 
 24 
 
"^he "U. 5. Commissior] of "Pish and ^Eisheriez. 
 
 Colonel Marshall McDonald, Commissioner. 
 
 The Commission was established primarily with the object of determiiiin<; llie 
 cause of decrease amons food-fishes, and of suggesting measures for the improvement 
 of the fishing grounds. Its scope, however, has been rapidly enlarged to cover all 
 matters pertaining to fisheries which come within the jurisdiction of the general gov- 
 ernment, including the propagation of useful fishes and the methods and statistics of 
 the fishing business. Colonel Marshall McDonald, the present Commissioner, suc- 
 ceeded Professor Spencer F. Baird, upon the death of the latter in 1887. 
 
 The work of the Commission is arranged under three divisions, as follows : The 
 Division of Scientific Inquiry is charged with the investigation of the fishing grounds 
 relative to their resources and characteristics, their depletion and the methods suited to 
 their replenishment ; and also with the study of the habits and development of fishes 
 as a basis for fish culture, legislation and fishery methods. The Division of Fish Cul- 
 ture undertakes the propagation of food-fishes, their distribution to different localities, 
 the restocking of exhausted grounds, and the introduction of useful foreign species. 
 The Division of Fisheries considers the methods and apparatus of the fishermen with 
 a view to their improvement^ and collects the statistics of the different branches of the 
 business. 
 
 The investigations along the seacoasts are chiefly carried on by means of two 
 steamers, the Albatross and Fish Hawk, and one sailing vessel, the schooner Grampus. 
 The xVlbatross is now stationed on the Pacific coast, the Fish Hawk and Grampus on 
 the Atlantic coast ; the two latter vessels being also employed to some extent in fish 
 culture. There are two marine stations for the hatching of cod, mackerel, lobsters and 
 several other salt-water species, one located at Wood's Holl, the other at Gloucester, 
 Massachusetts. The former is also adapted to scientific inquiries, being provided with 
 large and well equipped laboratories for biological and physical research. A number 
 of fresh-water and anadromous fishes are propagated upon a very exhaustive scale, 
 the most important being the shad, lake whitefish, carp, Atlantic and Pacific salmon 
 and several species of trout. For conducting this work twenty-one stations have been 
 established in different parts of the country, each embodying the most approved methods 
 applicable to the branch of fish culture for which it is adapted. Several cars, specially 
 constructed for that purpose, are used for the distribution of the eggs and fry as well 
 as the adult fishes. 
 
 The ofiicers of the Commission are located in Armory Square, Washington 
 (B street southwest, between Sixth and Seventh streets). The same building contains a 
 biological laboratory, extensive aquaria for the study and display of salt and fresh- 
 water fishes, and also one of the principal shad-hatching stations, for which the supply 
 of eggs is obtained from the important fisheries of the Potomac river during the spring. 
 
 25 
 
Large ponds for the breeding of German carp are situated on the Mall near the Wash- 
 ington Monument. Tench, golden ide and goldfish are also produced there in small 
 numbers, and one of the ponds now contains about 2,000,000 shad fry of the last sea- 
 son's hatching. 
 
 Collections illustrating the work of the Fish Commission are exhibited by the 
 National Museum. The models of fishing boats, fishing apparatus and the Cetaceans 
 are displayed in the Museum building, and the fishes, mollusks, crustaceans and lower 
 marine invertebrates in the Smithsonian building, where a large part of the zoological 
 material obtained during the investigations of the Commission is also stored. 
 
 "EdueaMonal Insl^itutionz. 
 
 Gcorgetoivn University is the oldest educational institution of the Catholic 
 Church in America. Founded in 1789 ; incorporated as a university in 18 15. Has 
 collegiate, law and medical departments. President, Rev. J. Haven Richards, S. J. 
 
 The Colmnbian University was incorporated by Act of Congress February 9, 
 182 1, as a college and re -incorporated as a university in 1873. It has collegiate, law 
 and medical departments. Its main building is that within which the meetings of the 
 Congress of Geologists are held, corner of H and Fifteenth streets northwest. Presi- 
 dent, Dr. J. C. Welling. 
 
 Howard University is devoted to the higher education of the colored race. It 
 was founded in 1867, and is supported by the Government. It has a collegiate 
 department, and schools of theology, law and medicine. The average attendance is 
 300. President, Rev. J. E. Rankin. 
 
 Catholic University of Ajnerica. Founded in 1889. Situated at Brookland, a 
 suburb of the city, east of the Soldiers' Home. Is reached by the Metropolitan 
 Branch of the Baltimore and Ohio Railroad. The Divinity School is the only depart- 
 ment at present organized. The Rector is the Rt. Rev. John J. Keane, D.D. 
 
 Columbia Institution for the Deaf and Dumb and National Deaf Mute College. 
 This institution has two departments, a primary and a collegiate ; the former estab- 
 lished in 1S57, the latter in 1864. It is supported by Congressional appropriations. 
 The development of the institution has been from the first under the guidance of Dr. 
 E. M. Gallaudet, now President of the Faculty. This college is the only one in the 
 world for deaf mutes. It is situated ju.st beyond the northeastern boundary of tlie city 
 in the park called Kendall Green, a portion of the estate of Amos Kendall, the orig- 
 inal promoter of the school and its first President. 
 
 26 
 
Go'C'Cpnmenl' IPvintinq ©ffiee. 
 
 This building; is situated on the corner of North Capitol and 11 streets. It is 
 300 feet long on H street and four stories high. All the printing and landing ordered 
 by the Legislative, Ivxecutive and Judicial Departments of the Government is done 
 in this building. It is the largest establishment of the kind in the world. Open from 
 S a. m. to 5 p. m. 
 
 Ijibrariez of tJIashington. 
 
 The libraries of the General Government have arisen from the exigencies of 
 public business, and with the growth of new bureaus the formation of separate reference 
 libraries has become necessary. With few exceptions these libraries have been formed 
 with reference to the special need of bureaus, and though small are very complete 
 in their own subjects. 
 
 %ibpaF2 of (Congress. 
 
 The Library of Congress dates from the first meeting of Congress in the City 
 of Washington in 1800 ; it was burned by the British in 18 14; was replaced by the 
 purchase of Jefferson's Library and grew to contain about 55,000 books in 185 1, when 
 a fire destroyed all but 20,000 books. Since 1852 it has grown steadily and of late 
 rapidly. In 1866 the books accruing to the Smithsonian Institution by exchange 
 were diverted to the Library of Congress, and in 1867 the large historical collection 
 of Peter Force was purchased and added to it. It now numbers about 650,000 
 volumes. 
 
 House of l^cpresentatiTpez. 
 
 The Library of the House of Representatives is almost exclusively of a docu- 
 mentary character, containing legislative and executive volumes for the use of members 
 of the House. Including duplicates it numbers 125,000 volumes. 
 
 £enate. 
 
 The Library of the Senate was begun in 1852, and consists entirely of public 
 documents for the u-se of Senators. At present it contains 47,000 volumes. 
 
 27 
 
'E^eeul'i'oe TDat^zion. 
 
 The Library of the Executive Mansion is very like a miscellaneous family 
 library'. It began to accumulate in the time of President Madison and now contains 
 about 4,000 volumes. 
 
 Ztats T)cpapl'menl'. 
 
 The Library of the State Department dates from the organization of the govern- 
 ment, in 1789. It is made up of works on the laws of nations,- diplomatic and general 
 history, voyages and cognate subjects, and contains 50,000 volumes and 3,000 
 pamphlets. 
 
 The Bureau op American Republics has collected about 1,100 volumes 
 relating to the Spanish republics of this continent, with special reference to all 
 questions of international comity and commerce. 
 
 %TCciZ\xi?2 'Deparl'menl'. 
 
 The General Library of the Treasury is for the entertainment of Treasury 
 Department clerks and is mainly biography, history and fiction. It contains 18,000 
 volumes. 
 
 The Bureau op Statistics began in 1866 to collect the statistical publications 
 of the world, and now contains 5,000 volumes and 6,500 pamphlets. 
 
 The Coast Survey Library contains about 8,000 volumes and 7,000 pamph- 
 lets of highly special character. Its archives contain about 5,000 original manuscript 
 maps and 65,000 record books of observation, computation and reduction. Its collec- 
 tion of foreign maps and charts numbers 9,000. 
 
 The Light-House Board has a library begun in 1852, and containing now 
 3,496 volumes on light, sound, naval architecture and engineering. 
 
 The Marine Hospital Bureau has a library of 1,500 books and 1,000 
 pamphlets. 
 
 '^ap Deparl'menl'. 
 
 The General Library of the War Department was begun in 1832 under Secre- 
 tary Lewis Cass. It is devoted chiefly to military science and contains 30,000 volumes. 
 
 The Library of the Ordnance Bureau is devoted to military engineering, gun- 
 nery and military and civil law. It contains 3,000 volumes. 
 
 The Library of the Surgeon-General's Office has been formed since the war 
 of i86i-'65, and is practically the medical section of the Library of Congress. It 
 covers the entire field of medical and surgical literature, and contains 101,969 volumes 
 and 152,225 pamphlets. 
 
 The Soldier's Home has a library dating from 1850. It is of a miscellaneous 
 character and contains 5,632 volumes. 
 
 28 
 
The Library at the Army Hradquarters, besnn by General Grant and added 
 to by Generals Sherman and Sheridan, is of considerable value for its especial purpose. 
 
 T}a;?2 'Depai'tmei2l'. 
 
 The General Library of the Navy Department is made up of historical, scientific 
 and legal works with especial relation to naval affairs. It numbers 24,086 volumes and 
 1,000 pamphlets. 
 
 The Bureau of Medicine and Surgery has a library of special reference 
 works of a medical and scientific character, which numbers 15,998 volumes. 
 
 The Hydrographic Office library was begun in 1867, and is made up of 
 hydrographical, nautical and meteorological works ; it contains al)Out 3,000 volumes 
 and 2,000 pamphlets. 
 
 The Library of the Naval Observatory dates from the founding of the Ob- 
 servator}' in 1843. It is a collection of the best works relating to astronomy, mathe- 
 matics and geodes}^ and niunbers 13,000 volumes and 3,000 pamphlets. 
 
 But a small portion of the library of the Post-Office Department is general lit- 
 erature. It consists of public documents pertaining to the duties of the office, and 
 numbers 8,000 volumes. 
 
 Interior T)eparl'menl'. 
 
 The Library of the Interior Department was begun in 1850, and is made up of 
 miscellaneous literature for the use of Department clerks. It has 10,500 volumes. 
 
 The Library of the Bureau of Education was begun in 1870, and contains 
 books and journals on educational topics, and school reports of all the world, to the 
 number of 17,500 volumes. 
 
 The General Land Office Library contains the laws and documents relating 
 to the public domain, and numbers 3,000 volumes. 
 
 The Columbia Institution for the Deaf and Dumb has a collection of 
 works relating to the instruction of the deaf and dumb surpassed by only one other in 
 the world. It numbers 4,000 volumes. 
 
 The Scientific Librar}^ of the Patent Office was begun in 1839, and contains 
 a very fine collection of works in all departments of science and all reports needed for 
 reference in determining questions concerning inventions. It numbers 50,000 volumes. 
 
 The Library of the Geological Survey is not yet ten years old, but has 
 already a practically complete collection of official geological reports and of the 
 standard w'orks on geology and its cognate subjects to the number of 30,000 volumes, 
 40,000 pamphlets and 22,000 maps. 
 
 29 
 
'Depaplrnenl' of Justice. 
 
 The Library of the Department of Justice was begun in 1853, and forms an 
 excellent collection of American, English, Spanish-American and Roman law books. 
 It contains 20,000 volumes. 
 
 The lyibrarj'' of the Solicitor op the Treasury dates from 1843, and is made 
 up wholly of law books and official documents for reference to the number of 7,000 
 volumes. 
 
 IDepaptmenl' of Sgrieulturc. 
 
 The Department of Agriculture has a collection of works on agriculture and 
 natural historN^ and their kindred branches, to the number of 24,000 volumes and 
 8,000 pamphlets. 
 
 The Library of the We.\ther Bureau was begun in 1871. It is made up en- 
 tirely of books on meteorology, telegraphy and cognate subjects to the number of 12,000 
 books and 2,500 pamphlets. 
 
 These libraries of the General Government contain more than 1,248,761 books 
 and 228,225 pamphlets, mo.st of which are accessible to any student in legitimate 
 scientific study. 
 
 Soeiet^ l^ibrariez. 
 
 Among important libraries not governmental should be noticed the following : 
 The American Medical Association Library, which contains 7,000 volumes, the 
 Law Librarj^ of the Bar Association, which numbers 7,000 books, the Library of the 
 Supreme Council 33°, a collection especially rich in works of histor5^ religion, phil- 
 osophy and folk-lore to the number of 15,000, which though especially intended for 
 and free to all masons is yet accessible to every student ; the Masonic Library of 
 3,000 volumes and the library of the Young Men's Christian Association numbering 
 2,000 books. 
 
 2ehool libraries. 
 
 Carroll Institute has a select library of 3,000 volumes ; Columbian Univers- 
 ity has a miscellaneous collection of 6,000 books and 2,000 pamphlets ; Georgetown 
 College possesses the fine Riggs Library of 35,000 volumes and of very broad scope ; 
 Gonzaga College and St. John's College have special libraries of 10,000 and 4,000 vol- 
 umes respectively ; and Howard University has 15,000 books, among which are some 
 rare Americana. 
 
 A general table of Washington libraries is here given : 
 
 .30 
 
tClashington Ijibraries. 
 
 Academy of the Visitation, 
 
 American Medical Association. 
 
 Bar Association, ..-..- 
 
 Bureau of Education — Gov't, - - - - 
 
 Bureau of Medicine and Surgery — Gov't, 
 Bureau of Ordnance (Navy Dept.) — Gov't, 
 Bureau of Statistics (Treas. Dept.)— Gov't, - 
 Carroll Institute, ------ 
 
 Coast and Geodetic Survey — Gov't, 
 
 Columbia Institution for Deaf and Dumb, 
 
 Columbian University, - . . - - 
 
 Department of Agriculture — Gov't, 
 
 Department of Justice — Gov't, . . . - 
 
 Department of State — Gov't, . - - - 
 
 Department of the Interior — Gov't, 
 
 District of Columbia — Gov't, - - - - 
 
 Executive Mansion — Gov't, - - - - 
 
 General Land Office — Gov't, . - - - 
 Geological Survey — Gov't, . - - - 
 
 Georgetown College, (Riggs Eibrary), 
 Gonzaga College, ------ 
 
 Government Hospital for the Insane — Gov't, 
 
 Health Department, D. C— Gov't, - 
 
 House of Representatives — Gov't, 
 
 Howard University, ----- 
 
 Hydrographic Office — Gov't, - - - - 
 
 Library of Congress — Gov't, - - - - 
 
 Library of Supreme Council 33° southern jurisdic- 
 tion U. vS. A., - 
 Light Battery C, 3d Artillery - - - - 
 
 Light-House Board (Treas. Dept.)— Gov't, - 
 
 Marine Hospital Bureau — Gov't 
 
 Masonic Library, ------ 
 
 Nautical Almanac Office — Gov't. 
 
 Naval Ob.->ervatory — Gov't, ----- 
 
 Navy Department — Gov't, - - - - 
 
 Patent Office Scientific Library — Gov't, 
 Post-Office Department — Gov't, 
 
 U(juk.s. 
 1,000 
 7,000 
 7,000 
 17.500 
 15-998 
 3,000 
 5,000 
 3,000 
 8,000 
 4,000 
 6,000 
 24,000 
 20,000 
 50,000 
 10,500 
 2,000 
 4,000 
 3,000 
 30,000 
 35.000 
 10,000 
 2,480 
 2,000 
 125,000 
 15,000 
 3,000 
 650,000 
 
 15,000 
 2,000 
 
 3.496 
 
 1,500 
 
 3,000 
 
 1,600 
 
 13,000 
 
 24,086 
 
 50,000 
 
 8,000 
 
 r.imiililcls. 
 
 6,500 
 
 7,000 
 
 2,000 
 8,000 
 
 3,000 
 
 42,000 
 
 2,000 
 200,000 
 
 1,000 
 
 3.000 
 1,000 
 
 i'i 
 
 31 
 
tQashington Ijibrarics (Continued.) 
 
 St. John's College,' ----- 
 
 Senate— Gov't, . - - - - 
 
 Soldiers' Home— Gov't, - . - - 
 
 Solicitor of the Treasury — Gov't, 
 
 Surgeon General's Office, U. S. Army— Gov't, 
 
 Treasury Department — Gov't, - 
 
 War Department — Gov't, - - - - 
 
 Weather Bureau — Gov't, - - - - 
 
 Young Men's Christian Association. - 
 
 Total, ------ 
 
 Hooks. 
 
 4,000 
 47,000 
 
 5.632 
 
 7,000 
 
 101,969 
 
 18,000 
 
 30,000 
 
 12,000 
 
 2,000 
 
 Pamphlets. 
 
 1,362,761 
 
 152,225 
 
 2,500 
 
 230,225 
 
 "* The existence of this vast body of literature in the city has naturally operated 
 against the formation of great private libraries in Washington, but there are neverthe- 
 less some worthy of notice. 
 
 The historical library of the late George Bancroft, the general libraries of 
 Justice Joseph Bradley, Justice Horace Gray, Mr. Henry Adams, Col. John Hay and 
 Mr. John G. Nicolay, the musical library of Mr. Edward Clarke, the Scotch library of 
 Mr. Wm. R. Smith, the library of Americana of Mr. L. A. Brandenburg, and the col- 
 lection of books relating to the civil war of i86i-'65 which Mr. John Davenport has 
 collected, are very fine in their class. 
 
 One of the interesting collections in the city is the one made by Mr. Frederick 
 Schneider who, in the intervals of a life as an iron founder and dealer in hardware, has 
 through correspondence with booksellers of Europe collected a library of illustrated 
 books, from the Nuremburg Chronicle to the present day, which contains rarities not 
 in the great libraries. He has printed an annotated catalogue of his treasures, setting 
 the type and doing all the press-work, etc., with his own hand. 
 
Qeneral Informahon. 
 
 A Bureau of Information will be maintained during the sessions of the 
 Congress in the Columbian University, where some one will be in constant attend- 
 ance. Programs, circulars, the Washington Directory, railroad guides and time- 
 tables, etc., may be found here. Macfarlane's Geological Railway Guide and local 
 guide-books to Washington may be purchased at the bureau. 
 
 The Telephone is free for use of members by courtesy of S. M. Bryan, President 
 of the Chesapeake and Potomac Telephone Company. The District Messenger call 
 may be used for messengers, cabs, etc., and telegraph. 
 
 There will be a temporary Post-OJJiee in the building, where mail for members 
 will be found. Stamps can be purchased here, and the Postal Guide consulted. 
 
 Money Exehange.—Voteign members of the Congress desiring to exchange 
 foreign currency can do so at the banking house of Crane, Parris & Co., No. 1344 F 
 street northwest. Arrangements will also be completed whereby this exchange can be 
 made at the office of the Congress in the Columbian University. 
 
 Zeientifie Soeiel'ies Of IQashingl'on. 
 
 Organized 1871 
 
 Philosophical Society, - - - - 
 
 President : T, C. Mendenhall. 
 Anthropological Society, - - - - 
 
 President : J. C. Welling. 
 
 Biological Society, - - - - 
 
 President : C. Hart Merriam. 
 
 Chemical Society, - - - - 
 
 President : R. B. Warder. 
 
 Microscopical Society, - - - - 
 
 President : Thomas Taylor. 
 
 Entomological Society, - - - - 
 
 President : George Marx. 
 
 National Geographic Society, 
 
 President : Gardiner G. Hubbard 
 Women's Anthropological Society, 
 
 President : Alice C. Fletcher. 
 
 Organized 1S79. 
 Organized 18S0. 
 Organized 1884. 
 Organized 1884. 
 Organized 1884. 
 Organized 1888. 
 Organized 1885. 
 
 33 
 
0ffiec2 of "Eopcign Ibegat^ionz.* 
 
 \ Austria- Hungary : 1537 I street northwest. 
 
 Chevalier de Tavera, Envoy Extraordinary and Minister Plenipotentiary. 
 
 f Belgium : 1336 I street northwest. 
 
 Mr. Alfred I^e Ghait, Envoy Extraordinary and Minister Plenipotentiary. 
 
 France: 1901 F street northwest, (two squares west of the State, War and Navy 
 Building). 
 Mr. Theodore Roustan, Envoy Extraordinary and Minister Plenipotentiary. 
 
 t Germany : 734 Fifteenth street northwest, (opposite the Columbian University). 
 
 Count Ludwig von Arco-Valley, Envoy Extraordinary and Minister Plenipo- 
 tentiar3^ 
 § Great Britain : Corner Connecticut avenue and N street northwest. 
 
 Sir Julian Pauncefote, Envoy Extraordinary and Minister Plenipotentiary. 
 
 f Italy : 729 Eighteenth .street northwest. 
 
 Marquis Imperiali di Francavilla, Charge d' Affaires. 
 
 \ Mexico : 141 3 I street northwest. 
 
 Senor Don Matias Romero, Envoy Extraordinary and Minister Plenipotentiary. 
 
 Netherlands : Office of the Consulate-General of the Netherlands, New York City. 
 Mr. G. de Weckherlin, Envoy Extraordinary and Minister Plenipotentiary. 
 
 § Russia : 1 705 K street northwest. 
 
 Mr. Alexandre Greger, Charge d'Affaires. 
 Spain : 1400 Massachusetts avenue northwest. 
 
 Senor Don Miguel Suarez Guaues, Envoy Extraordinary and Minister Pleni- 
 potentiary. 
 
 ^ Sweden and Norway : 201 1 Q street northwest. 
 
 Mr. J. A. W. Grip, Envoy Extraordinary and Minister Plenipotentiary. 
 
 % Switzerland : 2014 Hillyer Place northwest. 
 
 Mr. Alfred de Claparede, Envoy Extraordinary and Minister Plenipotentiary. 
 
 eiubz. 
 
 Cosmos Club — H street, opposite The Arlington. 
 
 Metropolitan Club — Corner of Seventeenth and H streets northwest. 
 
 University Club— No. 1726 I street northwest. 
 
 United Service Club — G street, near Seventeenth street northwest. 
 
 * Only those countries are given from which members are in attendance at the Congress. 
 
 Those marked t are within three squares of the Cohimbian University. 
 
 Those marked ^ are easily reached by the cars passing the Columbian University on H street. 
 
 34 
 
Holiel Heeommodal'ions. 
 
 Sjiecial rates have been secured for nienibcrs of the Conj^rcss at the foHowiiig hotels, which 
 are within five miiuites' walk of the Columbian University. 
 
 Arlington Hotel (Headquarters) — On Vermont avenue from II to I streets. (American plan). 
 Re_nular rate $^ per day and upwards, according"; to accommodations. A reduction of one-third of 
 these rates will be allowed to members of the Couj^ress. 
 
 The Arno — On Sixteenth street, between I and K streets. (European ])lan). Rooms at |;i 
 each for members of the Congress, including use of the hotel baths. Private bath-rooms $i per day 
 extra. Restaurant and cafe inj.he hotel. 
 
 I'lhbitt House — Corner of F and Fourteenth streets. (American plan). Adjoining the olTices 
 of the U. S. Geological vSurvey, Regular rates $4 per day. Rates to members of the Congre.ss f 2.50 
 per day and %\ extra for rooms with bath. 
 
 The. Elsfnere 1408 H street, between F'ourtecnth and Fifteenth streets. Board ami lodging 
 for members of the Congre.ss at ^10.50 per week during the meeting.s. 
 
 Arrangements have been made to i)rovide apartments in lodging-houses for such as may desire 
 them. 
 
 T)pix?es !Zilpound TQashingl'on. 
 
 The Soldiers^ Home. — This is one of the most attractive drives in the suburbs of the city. The 
 grounds are beautifully laid out and are kept up as a park. President Lincoln resided here in the 
 summer during his administration. It is three miles from the Arlington Hotel. 
 
 ^■lrli}i<^foji and Fort 3Tyer, situated on Arlington Heights, overlooking the Potomac. The 
 former was the home of George Washington Custis, and in later 3ears was the residence of txeneral 
 Robert E. Lee. The estate was sold under the confiscation act of 1863, and 200 acres set apart as a 
 National Cemetery. Over 16,000 soldiers lie buried here. General Sheridan's grave is but a short 
 distance from the house. The drive is through Georgetown and over the Aqueduct Bridge. I'rom 
 the portico the view of the Potomac Valley is exceptionally fine and adds much to the pleasure of 
 the drive. Distance from Washington, five miles. 
 
 An attractive drive is through the northwest portions of the city to the Zoological Patk, 
 thence northward to the country in and adjacent to the new Rock Creek Park. 
 
 vStill another drive is to follow the Conduit Road along the north and east side of the Potomac 
 River to Gle7i Echo Heights and Cabin John Bridge. The bridge is a magnificent structure spanning 
 Cabin John Run ; it is 20 feet wide, w'ith an extreme length of 420 feet. It is said to be the largest 
 single span stone arch in the w'orld. At the hotel near the bridge one can obtain a good dinner. 
 
 R. L- Cooper, No. 1335 H street northwest, offers the following .special reduced rates for 
 carriages to members of the Congress : 
 
 To Soldiers' Home and return, #3. 
 ' To Arlington and I'ort Myer and return, ^4. 
 
 To Cabin John Bridge and return, $5. 
 
 William F. Downey, No. 1624 L street northwest, and B. P\ McCaully & Co., No. 920 O street 
 northwest, also offer reduced rates for carriages. 
 
 35 
 
"E-^eupzions in the neighborhood of Idashingl'on. 
 
 Mount rernoti — the fi)niier residence and now the Tom1) of Washington — situated on the 
 Potomac river, ten miles lielow the Capitol, is easily reached b}- sleamer which leaves daily, except 
 JSunda}-, at lo a. m. The boat reaches the city on its return trip at 2.20 p. m. Fare, round trip, $1, 
 including admission to Mount Vernon. 
 
 Old Point, Fort Monroe, and I'^irs^inia Beach. These points, on the Virginia shore, are 
 reached by the iiew steamers of the Washington and Norfolk line, which leave Washington daily at 
 7 p. m., passing the evening and night on the Potomac river and Chesapeake bay, arriving at Old 
 Point at 7 a. m. the following day. Here the time may be pleasantly spent in visiting the Hygeia 
 Hotel, Fort Monroe, and the Soldiers' Home at Hampton. Those remaining on the steamer reach 
 Norfolk at S a. m., where the day may be passed in visiting the city, the U. S. Navy Yard at Ports- 
 mouth, or taking a short trip by rail to Virginia Beach, on the Atlantic. Returning steamers leave 
 Norfolk at 5 p. m., Old Point at 6 p. m., arriving in Washington at 7 a. m. the following day. Fare, 
 round trip, ^5. .Staterooms, %\ and %2 each way, according to location. 
 
 Liiray Cavern, Virginia, situated about one mile west of Luray station, on the vShenaudoah 
 Valley Railroad, and sixty-five miles from Washington, is reached by the Baltimore and Ohio Rail- 
 road, connecting at Shenandoah Junction for Luray. The best excursion is that leaving Washington 
 from the Baltimore and Ohio Depot at 3.30 p. m., arriving at Luray at 7.45 p. m. Visit the Cavern 
 that evening, after supper at Luray Inn. Leave Luray the following day at 7.10 a. m., arriving in 
 Washington about 11.45 a- "'■ Those wishing to see Harper's Ferry and vicinity can stop over and 
 find trains to Washington at 3.06 p. m., 4.25 p. m. and 6.18 p. m. Fare, Washington to Luray and 
 return, fc.50. Admission to the Cavern, |;i.oo. Board at Luray Inn, |;2.oo and I2.50 per day. 
 
 'E^eurzions afl^er l^hc (Congress. 
 
 Members of the Congress will have received the Congress Circular giving the itinerary of the 
 long excursion which it is proposed to make from Washington to the Yellowstone Park, vSalt Lake, 
 Denver, and back via Chicago and Niagara I<'alls to New York, starting September 2d, and to be 
 en route twenty-five days. The expense of this trip will be 1:265.00 for each person. 
 
 Another excursion contemplated by the Congress Committee will leave Washington Septem- 
 ber 2d, and make a circuit through Pennsylvania, via Philadelphia, Pottsville, Wilkesbarre, Harris- 
 burg and Cresson, visiting the Anthracite basins, and localities made famous by Rogers and Lesley 
 as illustrating Appalachian stratigraphy, structure and topography. Glacial phenomena will be .seen 
 at Berwick. The production and use of oil and gas will be shown at Pittsburg. From Pittsburg 
 the party will pass through the Connellsville coke region, the Valley of Virginia, stopping at Luray 
 Cave ; thence down the New river gorge to Pocahontas, and to Middleboro' at Cumberland Gap ; 
 return via Knoxville, across the PaUeozoic of Tennessee and the Archieau of North Carolina, and up 
 the coastal plain to Washington. The carrying out of this plan will depend upon the nunil)er wish- 
 ing to make the trip. Railroads have cordially offered reduced rates, and mining companies oppor- 
 tunities for seeing the things of interest. The cost will probably fall below |ioo, and sixteen days 
 will be required. A special descriptive circular and itinerary will be issued. 
 
 36 
 
21'pcel' Gap Tjines. 
 
 Street car fare, 5 cents, or 6 tickets for 25 cents. Tickets of one line received for fare on all 
 other lines 
 
 Transfer tickets can be obtained at points of intersection of lines belonj^ing to the same Com- 
 pany. (See map.) 
 
 The green cars of the Metropolitan Railroad Company passing the Columbian University on H 
 street go west to Georgetown, passing the Legation of Great Britain, and near those of Russia, Sweden 
 and Norway, and Switzerland (see p. 34). They go east past the U. vS. Geological Survey, Patent 
 Office, Post-Ofiice Department, Pension Building, Baltimore and Ohio Railroad depot, the Capitol, and 
 out East Capitol street one mile to Lincoln Park. On Ninth street is another line belonging to this 
 Company. These cars go north beyond the city limits and south past the Baltimore and Potomac 
 Railroad depot to the wharves at the foot of Seventh street. 
 
 One block south from the University the cars of the Washington and Georgetown Railroad 
 Compan}' go west past the White House to Georgetown, and south past the Treasury Department to 
 Pennsylvania avenue, thence east to the Capitol and Navy Yard. They pass near the depot of the 
 Baltimore and Potomac (Pennsylvania) Railroad on Sixth street. By transfer to the caljle cars on 
 Seventh street one can go north to the city limits or south past the Fish Commission and Army Med- 
 ical Museum to the steamboat wharves and the Arsenal grounds. 
 
 On Fourteenth street, one block east of the Columbian University, is another line of cars of the 
 Washington and Georgetown Railroad Company. These go north to the city limits, while southward 
 they join the main line at the Treasury Department, so that from this point to the Capitol the cars of 
 the two lines alternate. The Fourteenth street cars leave Pennsylvania avenue at the foot of Capitol 
 Hill and go to the Baltimore and Ohio depot. 
 
 Rates of Fare for Hacks, Cabs and Other Vehicles. 
 
 {^Extract from Police Regulations). 
 
 RV TMP MriTTH Between 3 a.m. Het'n 12.30 a.m. 
 
 BY fHh, HOUR. and 12.30 a.m. and 5 a.m. 
 
 For one passenger or two passengers, for the first hour ^75 $1 00 
 
 For each additional quarter of an hour or part thereof 20 25 
 
 Provided, That for multiples of one hour the charge shall be at the 
 
 rate per hour of 75 i 00 
 
 For three or four passenger, for the first hour i 00 i 25 
 
 For each additional quarter of an hour or part thereof 25 35 
 
 Provided, That for multiples of one hour the charge shall be at the 
 
 rate per hour of 100 i 25 
 
 BY THE TRIP. 
 
 By the trip of fifteen squares or less for each passenger 25 40 
 
 For each additional five squares or part thereof 10 15 
 
 Provided, That for multiples of fifteen squares the charge shall be 
 
 at the rate for each fifteen squares of 25 40 
 
 Two-horse hacks, for four persons, may charge I1.50 for the first hour, and 25 cents additional 
 for each extra quarter hour. 
 
 Railroads. 
 
 Baltimore and Potomac (Pennsylvania) Railroad, "j 
 
 Richmond and Danville Railroad, >• Depot : Corner Sixth and B streets northwest. 
 
 Chesapeake and Ohio Railroad, j 
 
 Baltimore and Ohio Railroad — Depot : Corner New Jersey avenue and C street northwest. 
 
 37 
 
%h2 Geology of tnashingl^oi] and ^Oieinil'^/''' 
 
 PACK 
 
 The General Physiographj-, ....---.- 38 
 
 The Local Physiography, ....----- 41 
 
 The General Geology, - - - - - - - - - - 43 
 
 The Rocks of the Piedmont Plateau, ------- 43 
 
 Present State of Knowledge, .-.-----43 
 
 The Rocks and their Relations, .-.--.-- 43 
 
 The Formations of the Costal Plain, - - - -.- - - - 44 
 
 Present State of Knowledge, ...--.- 44 
 
 The Formations and their Relations, ---.---46 
 
 The Geology of the Appalachian Zone, ------- 53 
 
 Present State of Knowledge, --------53 
 
 The Origin and Relations of the Rocks, ------ 54 
 
 The Appalachian Structure, --------55 
 
 The Local Geolog}-, ---------- 56 
 
 Crystalline Rocks of Washington, --------56 
 
 General Features, ---..-_.- 56 
 
 Leading Rock Types, ......... c^-j 
 
 Clastic Formations of Washington, ------- 59 
 
 The General Structure, ...------59 
 
 The Columbia Formation, -..-.-.- 60 
 
 The Lafayette Formation, .--_---. 60 
 
 The Chesapeake Formation, -------- 60 
 
 The Pamunkey Formation, . - - - - - - - - 61 
 
 The Severn Formation, -------- 61 
 
 The Potomac Formation, - - - - - - - - - 61 
 
 Post-Columbia Deposits, -------- 62 
 
 Artificial, ........... 62 
 
 The Geomorphology, ---.--..-- 62 
 
 The General PhysiocxRAphy. 
 
 There are in eastern Uniled States three distinct physiographic provinces. 
 Most conspictions of these is the Appalachian zone, an area of long, low motmtain 
 chains of wonderful parallelism. At the eastern base of the mountains lies the 
 Piedmont plateau, an undulating plain standing 500 to 1000 feet above sea level. 
 Between this plateau and the ocean lies the Coastal Plain, a generally smooth lowland 
 rising gently from ocean waters to altitudes reaching about 300 feet. 
 
 The rocks of the Appalachian zone are Paleozoic, running from the Carbon- 
 iferous down to the Cambrian and probably to the Algonkian, aggregating 25,000 
 to 40,000 feet in thickness. The entire series is nearly or qtiite conformable ; the 
 
 * Prepared by W J McGee, with the collaboration of Professor G. H. Williams, and Messrs. 
 N. H. Darton and Bailey Willis. 
 
 38 
 
materials range from coal seams toward the summit, and pure limestone at various 
 horizons, to coarse sandstones, and in Peinisylvania to great beds of conglomerate. 
 The strata, originally horizontal or slightly inclined westward, have been deformed 
 and altered in a variety of ways. In the western and central portions of the ])rovince 
 they have been flexed symmetrically and thrown into a series of anticlinal and syn- 
 clinal corrugations, seldom more than a mile or two in width though often scores or 
 even hundreds of miles in length— a series of mountain-folds unparalleled elsewhere 
 (Ml the globe in length, symmetry, and concordance in direction. In the central part 
 of the zone the symmetric flexing is combined with faulting, and in many cases the 
 faulting is of that overthrust type which characterizes the Scottish Highlands and 
 the Canadian Rocky Mountains. In the eastern portion of the zone the symmetric 
 flexing fails, faulting (both normal and overthru.st) prevails, and the rocks are more or 
 less profoundly metamorphosed — the limestones transformed into marbles, the shales 
 into slates, the sands into quartzites. Throughout the province the distinctive struc- 
 ture and the rock composition are both reflected in topographic configuration ; the 
 prevailing forms are long narrow ridges, separated by long and generally narrow 
 valleys ; but these land forms represent respectively the outcropping edges of hard 
 strata and soft beds rather than original flexures. 
 
 The rocks of the Piedmont belt are more or less crystalline, chiefly metamor- 
 phic schists and gneisses of considerable diversity in composition, but sometimes 
 including ancient eruptives, as well as quartz veins and dikes. The structure of the 
 province is obscure and diverse, and has not yet been fully investigated. It is known, 
 however, that in the latitude of Washington at least the Piedmont belt is separable 
 into two distinct parts. Of these the western is composed of semi-crystalline slates, 
 phyllites and schists having a constant inclination toward the east ; while the ea.stern 
 part is made up, except for a few included folds of the less crystalline rocks, of highly 
 crystalline gneisses and a variety of foliated eruptives, all of which have a prevailing 
 dip toward the west. The nearly vertical position of strata intermediate between 
 these extremes gives a pseudo fan-structure to a section of the Piedmont plateau in 
 Maryland. The line betw^een the western semi-crystalline and the eastern gneissic 
 areas is not a sharp one ; and there is an apparent progressive increase in the intensity 
 of metamorphism from the western border to the eastern limit of the Piedmont belt 
 by which casual students have been misled. The surface of the zone is characterized 
 by meandering stream channels and w^andering divides, with moderately strong local 
 relief ; yet, while the harder rocks of the province find a certain expression in the 
 topography, the general configuration is independent of rock structure but represents 
 baselevel conditions during past eons. 
 
 The composition and configuration of the Piedmont zone are locally diversified 
 by considerable areas of Mesozoic rocks, commonly referred to the Triassic. These 
 rocks are red sandstones and red or purple shales, with occasional beds of couglomer- 
 
 39 
 
ate. The}' are characterized by strong dips toward the Appalachian zone ; and they 
 are frequently cut and sometimes interbedded with or overlain by contemporaneous or 
 younger dikes and sheets of trap. In the northern part of the Coastal plain the trap 
 occurs in considerable volume, and forms prominent ridges by which the topography 
 of the entire Piedmont belt is dominated ; but in general the sandstones and shales 
 are soft and friable, and find topographic expression in low-lying plains and basins. 
 
 The rocks of the Coastal plain are clastic, ranging in age from Pleistocene to 
 middle IMesozoic, probably reaching a total thickness of 2,500 to 3,500 feet. The 
 entire series inclines gently seaward, the inclination increasing from the newer to the 
 older formations. The strata are manifestly made up of the debris of the Appalach- 
 ian and Piedmont provinces, are rarely lithified, and range from alluvium or alluvium- 
 like silts along the rivers and toward the coast, and glauconitic marls and fine clays in 
 the middle of the series, to coarse gravels and beds of arkose toward the base and near 
 the old shorelines. Except for the gentle inclination of the strata, and except for a 
 dislocation coinciding with the inland margin of the province, the strata are not visibly 
 deformed, but retain substantially the attitudes as well as the composition of original 
 deposition. The surface of the province is commonly characterized by meandering 
 rivers, throughout the middle Atlantic slope by broad estuaries, and in general by 
 broad low divides, often terraciform — the configuration seldom expressing structure or 
 localized earth movement, but representing simple erosion combined with wave action 
 during several continental oscillations of general character. 
 
 The western boundary of the Appalachian zone is indefinite ; the characteristic 
 corrugations gradually die out and the flexed strata of the Appalachian pass into 
 the undisturbed strata of the interior plain. 
 
 The common boundary of the Appalachians and the Piedmont zone is generally 
 trenchant, consisting of a prominent ridge of quartzite — -the Blue ridge. Somewhat 
 south of the latitude of Washington the ridge is simple and single ; where cut by the 
 Potomac river west of Washington it is triple or quadruple ; in Maryland and Pennsyl- 
 vania it is frequently multiple ; and in Virginia and the Carolinas it is sometimes 
 interrupted and again divided ; but in general it definitely marks a fairly decided 
 transition from comparatively simple to comparatively complex structure, and from 
 incipient metamorphism to pronounced alteration in the rocks. 
 
 Throughout the middle Atlantic slope the common boundary of the Piedmont 
 zone and the Coastal plain is pronounced ; along this line there is a svtdden and 
 decided transition in the rocks from highly altered crystallines to practically unaltered 
 elastics ; along this line the water-ways change from narrow, rock-bound gorges of 
 considerable declivity to broad tidal canals, and each river passes from the one prov- 
 ince to the other in a cascade or rapid ; along this line the rivers are diverted from 
 courses cutting across the trend of structure and athwart the provinces to courses par- 
 allel with the line of cascades, thus peninsulating most of the Coastal plain ; and along 
 
 40 
 
tliL- line tluis accenlualcd bv llic divL-rtcd (lr:iiii:ii;c Uiltc is conuuonl)- a proniiiieut 
 scarp of Piedmont rocks overlooking? the flat-lymi; rocks of the Coastal plain. This 
 physiographic l)i)nndary is one of the most trenchant on the surface of the globe, and 
 the uatural line is emphasized by a prominent cultural line to which it gave origin ; all 
 the principal cities of the eastern United States from New York to the Carolinas are 
 located along this natural landmark. 
 
 The eastern boundary of the Coastal plain may be drawn at the shore of the 
 Atlantic; but it may more properly be drawn loo miles offshore at the great sub- 
 marine escarpment, 3,000 to 10,000 feet high, hugged bv the Gulf Stream — in general 
 configuration, in inclination of the surface, and unquestionably in structure and compo- 
 sition, the subaerial and the submarine portions of the Coa.stal plain are es.sentially a 
 unit, and the present coast line is but an accident of present relation between sea and 
 land. 
 
 Despite the diversity in rocks, structure and configuration in the three prov- 
 inces, the principal rivers of the middle Atlantic slope traverse all alike. The Mohawk 
 and the Hud.son run around the northeastern extremity of the typical Appalachian 
 zone, separating the three distinctive provinces from the analogous (but probably not 
 homologous) physiographic tract of New England ; the Delaware, with its great 
 secondarys, the Lehigh, the vSusquehanna, the Potomac and the James, rise well 
 within the Appalachian zone, cut through the successive ridges in a series of clefts, 
 cross directly the Piedmont plateau, and, although diverted at the fall line, thence 
 intersect the Coastal plain to the Atlantic ; and except at the fall line their counses 
 are essentially independent of structural conditions. Yet even along the great 
 rivers the boundaries of the physiographic divisions find expression : The Appa- 
 lachian-Piedmont boundary is marked by narrow notches in the Blue Ridge, forming 
 the far-famed "water gaps" of the Delaware, of the Lehigh, of the Susquehanna near 
 Harrisburg, of the Potomac at Harper's Ferry, and of the James at Balcony P'alls ; 
 the Piedmont-Coastal boundary is still more strongly marked by the line of cascades 
 on every river, large and small, from the Raritan in New Jersey to the Roanoke in 
 North Carolina, and by the deflection of the water-ways which peninsulate the lowland 
 plain from New York to Richmond. 
 
 The Local Physiography. 
 
 The City of Washington, like the other metropoles of the middle Atlantic slope, 
 is located at the common boundary of the Piedmont and Coastal zones. The western 
 part of the city is built on the ancient crystallines, the eastern on the nou-lithified 
 elastics ; though outliers of the clastic formations occasionally occur on the uplands 
 .some miles farther westward. Located like neighboring metropoles at the head of 
 navigation, the city marks the po.sition of the fall line. At Washington the Potomac 
 river is tidal, and perhaps half a mile wide ; within four miles up stream the channel 
 
 41 
 
contracts at ordinary stages to barely loo feet, changing meantime from a slack-water 
 canal into a rnsliing torrent. This is the " Little Falls of the Potomac." Then follow 
 twelve miles of nearly continuous rapids to the " Great Falls of the Potomac," where 
 at ordinary stages the river contracts to about 50 feet and descends 40 feet in a suc- 
 cession of plunges of which the highest is about 15 feet. Between Great Falls and 
 Washington the river occupies a narrow gorge excavated in a broader one, whose bot- 
 tom averages 150 feet above tide ; above Great Falls the river wanders over the bottom 
 of the older gorge. 
 
 Just west of the city the embouchure of the gorge expands, and its walls merge 
 into the general Piedmont scarp overlooking the Coastal lowland. Just east of the 
 city lies Anacostia river, a goodly mill-stream only, clear and rapid in its headwaters 
 among the Piedmont hills, but sluggish and marsh-bordered for the last five miles of 
 its course. A century ago it was navigable, and trans- Atlantic shipping embarked 
 and debarked at Bladensburg ; but now it is clogged with alluvium and barely navi- 
 gable above the Washington Navy Yard. Between the rivers lies a triangular amphi- 
 theater, bounded on the west by the Piedmont scarp, on the north by a terraciform 
 upland, on the east and southeast by low bluffs carved out of Coastal plain deposits, 
 and opening .southward through the Potomac estuary. Most of this amphitheater, 
 together with the upland borders toward the north and west, is occupied by the 
 cit}-. 
 
 Southwest of the city there are extensive terraces, evidently wave fashioned but 
 deeply invaded b}' erosion ; north of the city the upland is similarl}' terraced, though 
 broad and deep ravines interrupt the continuity of the plains ; and beyond the Anacos- 
 tia most of the surface represents two or more wave-fashioned plains which, although 
 deeply scored by erosion, .sometimes maintain their integrity quite to the verge of the 
 river bluffs. The Fort Myer upland, southwest of the city, is simply the scarp 
 of a broad terrace ; Kalorama Heights and Columbia Heights toward the north- 
 west are the salients of a similar terrace ; Good Hope Hill on the southeast is a rem- 
 nant of another terrace ; the bluff on which the National Asylum of St. Elizabeth is 
 located is the scarp of a lower terrace of wonderful horizontality and continuity. Far- 
 ther westward and northward the .surface rises in less regular divides, crests, knobs and 
 .spurs ; but here and there terrace remnants are found up to over 400 feet above tide, 
 or nearly to the greatest altitudes of the region. 
 
 The terrace plains are built ; the broad, low, wave-fashioned plains flooring the 
 amphitheater are compo.sed of the newest deposits of the region ; the higher terraces 
 carved on the walls of the amphitheater are of earlier j^et late Tertiary origin. The 
 smaller ravines as well as artificial excavations reveal the materials of the terraces in 
 Inuidreds of exposures ; the larger ravines as well as artificial excavations reveal the 
 clastic formations beneath and east of the city in numberless exposures ; the Potomac 
 river and its larger tributaries are bound between steep, often precipitous, walls of the 
 
 42 
 
crystalline rocks. The entire region is dissected by water-ways and l)y a niullilude of 
 storni-cnt ravines, and so the local relief is strong except toward the interiors of the 
 broader terraces. 
 
 Tine Gknkral Gholo(;y. 
 
 TIIK ROCKS OF TIIP: TIEDMONT I'LATlvAi:. 
 
 Present State of K)undedo;c. — Since the beginnings of American geology the pre- 
 vailing crystalline character of the Piednient terrane lias been recognized, and the rocks 
 have commonly been referred to the Archean and frequently correlated on petrograj^hic 
 ground with the Huronian, Laurentian and other ancient rock systems of distant parts 
 of the country. During the last decade Dr. George II. Williams began systematic 
 work upon Piedmont rocks in the vicinity of Baltimore ; more recently his studies have 
 been extended westward across the entire zone along several lines in Maryland, Vir- 
 ginia and North Carolina. The more important results of these researches have been 
 published by the Geological Society of America. -i' \\\ means of the.se studies the pe- 
 trographic character, structure and relations of the Piedmont rocks about the latitude 
 of the National Capital have been made known. 
 
 The Rocks and their Relations.^ — The Piedmont plateau is divisible into an 
 X eastern highly cry.stalline and a western semi-crystalline portion. The former consists 
 of gneisses and holocrystalline mica schi.sts, quarlzites and marble, containing an 
 abundance of more or less dynamically metamorphosed eruptive masses. All of these 
 rocks have a prevailing north-northeast strike and a westerly dip. The western por- 
 tion, on the other hand, is composed of partially metamorphosed sedimentary strata 
 (sericite and chlorite schists, ottrelite schist, phyllite and limestone) and is nearly free 
 from ancient eruptives. The strike of these rocks conforms to that of the eastern por- 
 tion, but their dips are prevailingly toward the east. In spite of apparent conformity 
 and even indications of transitions between these two portions of the Piedmont region, 
 they are separated by a great time-break and unconformity. The easterly dips on the 
 west and the westerly dips on the east, together with the nearly vertical strata between, 
 produce a radiating or fan-structure, and the axis of this fan is not coincident with the 
 contact between the crystalline and semi-crystalline portions. The thickness of either 
 series of rocks, as indicated.by their present dips, would be so vast that w^e must assume 
 that the same beds are repeated over and over again by tightly compressed folds or 
 thrusts. In the absence of all paleontologic data it is impossible to a.ssign a definite 
 age to either of these series. In the light of what has been discovered elsewhere, how- 
 ever, it is not improbable that the western and semi-crystalline areas represent the older 
 Paleozoic horizons, metamorphosed by more intense dynamic action than has affected 
 
 *The Petropraphy and Structure of the Piedniout rialcau in Maryland Bull. (',eol. Soc. 
 Anier., vol. 2, 1890, pages 301-322. 
 tBv George H. Williams. 
 
 43 
 
them farther west, while the holocr^-stalline rocks on the east are a remnant of the pre- 
 Cambrian continent, from which the Paleozoic sediments were derived. The apparent 
 conformity betwen the two regions may be explained by supposing that the highly 
 crystalline rocks also formed the floor upon which the now semi-crystalline schists were 
 deposited as sediments. These older rocks, already greatly altered and folded, under- 
 went at the time of the Appalachian uplift one more final folding, which gave them 
 their now prevailing trend and carried the overlying Paleozoic .sediments with them. 
 ' This supposition is also in accord with the fact that several closed synclinals of slate 
 and semi-crj'stalline schists are found pinched into the gneisses far to the east of the 
 main contact. 
 
 The Formations of the Coastal Plain. 
 
 Present State of Knoioledge. — Although geologic reconnaissance was extended 
 over the portion of the Coastal plain lying in the middle Atlantic slope early in the 
 present centur}-, detailed surveys were not made until long after. So, while the com- 
 position, structure and age of the deposits w^ere known in general terms, little was 
 known of the precise limits of the several formations or of the geologic history 
 recorded within them (particularly about the National Capital) uiitil the middle of the 
 last decade. Soon after the organization of the present Geological Survey systematic 
 study was initiated ; within the next three years certain formations were discriminated 
 and classified, and the methods of investigation applicable in this distinctive if not 
 unique geologic province were developed. Subsequently detailed surveys were under- 
 taken, under the auspices of the Geological Survey, by Mr. Nelson H. Darton. Cer- 
 tain formations were by him discriminated and classified, and the composition, attitude 
 and precise areal distribution of the formations lying between the Potomac River and 
 Chesapeake Bay (the "western shore" of Maryland) as well in much of " tide-water 
 Virginia" were ascertained. The areal distribution of the clastic formations devel- 
 oped about Washington, as determined by Mr. Darton, is represented on an accompa- 
 nying map ; maps of other portions of the Coastal plain are not yet published. 
 
 The surveys north and south of the Potomac-Chesapeake peninsula, and of the 
 peninsula lying east of Chesapeake Bay (the "eastern shore" of Mar3dand and Dela- 
 ware) are not yet completed. Accordingly, while the formations enumerated below 
 are probably representative of the Coa.stal plain throughout much of the middle Atlan- 
 tic slope, the}' are in general accurately known only in the immediate vicinity of 
 Washington. 
 
 In the re.searches withitr the Coastal plain certain methods, developed as the 
 work progressed, have been constantly used ; and since these methods are distinctive, 
 and since moreover they affect materially the results of the work, they may briefly 
 be stated : 
 
 44 
 
(i). Reconnaissance and preliminary snrveys showed lliat the Coastal plain 
 deposits are commonly thin bnt extensive, and each composed of distinctive materials, 
 only a part of the series being- fossiliferons. Moreover the Coastal plain is vast, 
 extending over fnlly 15° of latitude and 25° of longitude, and including the deposits 
 of the greatest river of the continent, of many variously conditioned rivers of less size', 
 and of coasts receiving little terrestrial drainage ; from which it was inferred that the 
 distribution of organisms during past eons was affected by diverse conditions of envir- 
 onment, much as the fauna and flora of the present are affected. Accordingly it was 
 deemed feasible to define the formations by composition, attitude and physical relations, 
 and to trace formations from place to place throughout the province by means of strati- 
 graphic continuity, independently of fossil remains, presumptively varying from ]ilace 
 to place with the varying environmental conditions of the periods of deposition. Thus 
 the formations discriminated in the Coastal plain are e.s.sentially phy.sical units. 
 
 (2). As research progressed, it was found that in many cases the materials of 
 the successive Coastal plain deposits may be traced to their sources, and that their 
 character and distribution. indicate the proximity of shores, the depth of waters, the 
 positions and characteristics of sediment-bearing rivers, etc. Thus it was found that 
 each formation represents a certain general relation between sea and land, the recogni- 
 tion of which easily explained local variations in the physical condition of the deposits ; 
 and thus the tracing of the formations by stratigraphic continuity was facilitated and 
 extended. So each Coastal plain formation is a physical unit, and at the same time 
 an expression of the general physiography of the continent during the period of its 
 
 deposition. 
 
 (3). As researches into the relations of land and sea during the several eons 
 ' progressed, it was found that in many cases the character and distribution of deposits 
 composing the formations indicate not only the position and size of sediment-bearing 
 rivers, but the declivities and other conditions of those rivers, which in turn indicate 
 the attitude, altitude and general configuration of the land surface during the period 
 of deposition. It was also found that in many cases the land-forms themselves record 
 geologic history definitely and intelligibly as the deposits from which history is com- 
 monly read ; and accordingly the deposition-record was in many cases supplemented 
 by the degradation-record. So, many of the Coa.stal plain formations not only repre- 
 sent general physiographic conditions, but yield detailed records of geography and 
 topography during the periods of deposition. 
 
 (4). As the discrimination of successive deposits of the sea and of the variously 
 superimposed topographies of the land in the -Coastal plain and Piedmont provinces 
 I)rogressed, it became evident that any local tract gives a record of a certain series of 
 physical episodes, each of definite character, and that recognition of the conditions 
 of each episode facilitates the tracing of deposits from place to place, even throughout 
 the entire Coastal plain and far \yithin the contiguous provinces of concurrent degra- 
 
 45 
 
dation. Thus it was found feasible not only to correlate formations with aspects of 
 the land in each tract, but to correlate the tracts of a vast area by means of genetic 
 identity, or by homogeny.* So, certain of the Coastal plain formations discriminated 
 in the Atlantic slope represent not simple records of local physiographic conditions, 
 but exact indices of geographic and topographic conditions extending over a considera- 
 ble fraction of the continent. 
 
 For these reasons the taxonomy of the Coastal plain formations is largely inde- 
 pendent of the paleontologic scale. Accordingly, while each formation is known to 
 record a definite episode of continental history, its paleontologic position can seldom 
 be indicated with accuracy in the present state of knowledge, and perhaps cannot be 
 ascertained until researches have extended over the entire Coastal plain, and until the 
 distribution of organisms during each episode in Coastal plain development is deter- 
 mined with precision. 
 
 The Formations and their Relations . — The Clastic formations found in the middle 
 Atlantic slope, the geologic groups to which they are provisionally assigned, the 
 thickness, attitude, and certain other characters of each, the history indicated by their 
 physical relations, together with the approximate paleontologic position of each episode 
 (whether of deposition or degradation), are indicated in the accompanying table ; the 
 distribution, as determined by Mr. Darton, being shown in the accompanying map : 
 
 PAIvEONTOIvOGIC 
 FORMATION. CHARACTERS. POSITION. 
 
 I Alluvium Thickness unkuown ; chiefly below tide; undisturbedt. ... 1 I^ate Pleistocene 
 
 SI _ -^ ' J and modern. 
 
 ■2 -| Erosion interval ; dissection of Colnmbia Pleistocene. 
 
 I I Columbia ... ...Thickness 5-40 feet, altitude 150 feet ; undisturbed Early Pleistocene. 
 
 ^ L Erosion interval ; extensive invasion of Lafayette Pliocene (?) 
 
 Lafayette Thickness 5-50 feet ; altitude 500 feet ; undisturbed Pliocene (?) 
 
 Erosion interval ; extensive planing of Chesapeake Miocene (?) 
 
 (r//i!'.s-rt/c'(?/7'.... Thickness 10-125 feet ; tilted slightly; fossiliferous Miocene. 
 
 Erosion interval; extensiveplaningofPamunkey and Severn ? 
 
 Pamtmkey Thickness 3-100 feet ; tilted slightly ; fossiliferous : Eocene. 
 
 o ] Erosion interval ; extensive planing of Severn and Potomac ? 
 
 ^ 
 
 L 
 
 Severn Thickness 2-25 feet ; tilted .seaward; fossiliferous Cretaceous. 
 
 Erosion interval ; profound dissection of Potomac Cretaceous. 
 
 I "j /Wowaf. ..... ...Thickness 5-500 feet ; considerably tilted ; fossiliferous Early Cretaceous. 
 
 t3 Long interval of extensive and profound erosion Jurassic (?) 
 
 * American Journal of Science, third .series. Vol. XL,, 1890, page 36. 
 
 t Except by a late Neocene displacement which is yet in progress (c. f. 7th Ann. Rep. U. vS. 
 Geol. Survey, 1888). 
 
 46 
 
There is a notable dearth of alliuinm Ihrouj-^liout the middle Atlantie slope ; 
 west of the "fall line," which is not only the coiunion bonndary of two stron<;ly dis- 
 tinj^uished iirovinces but a line of modern dislocation as well, the land is rising so 
 rapidly that the rivers, albeit rapid and generally rushing torrents, are unable to cut 
 their channels down to baselev^el ; east of the "fall line" the land is sinking so 
 rapidh' that deposition in the estuaries, albeit localized and ra[)id, does not keep pace 
 with the sinking. 
 
 Anterior to the vaguely limited periotl which may be assigned to alluvium 
 deposition the land stood higher than now, for the antecedent formations are deeply 
 antl broadly trenched l)y the Potomac, the Anacostia, and other Coastal i)lain rivers ; 
 but whether it was the entire region or only the now sinking Coastal plain that 
 formerly stood higher is not certainly known. It seems probable, however, that both 
 Piedmont and Coastal provinces were elevated after Columbia deposition, that both 
 were subsequently depres.sed to some extent, and that while the downward movement 
 of the Coastal plain continues, the movement of the Piedmont i)lateau w'as long since 
 reversed. 
 
 The Columbia formation-i^ commonly consists of brown loam or brick clay, 
 grading downward into a bed of gravel or bowlders. Toward the embouchures of the 
 larger rivers from their Piedmont gorges the loam commonly thins, and the bowlder 
 bed thickens ; in the remoter parts of the estuarine valleys the loam thickens, the 
 bowlder bed thins, the materials become finer, and a sand bed often separates loam and 
 gravel ; farther down the estuaries the gravel bed commonly disappears, and the loam 
 becomes iuterstratified and .sometimes intermixed with silt. Between the rivers the 
 deposit extends over divides up to altitudes of about 150 feet in the latitude of Wash- 
 ington, increasing northward and decreasing southward ; and in such interstream 
 areas the deposit is more heterogeneous than along .the rivers, and contains a consider- 
 able element of materials corresponding with those of the immediate subterrane. As 
 a whole the deposit evidently represents littoral and chiefly estuarine deposition. 
 The materials differ from tho.se of the modern alluvium in (i) greater dimensions of 
 the bowlders, (2) greater coarseness of sediments in general, and, (3) less complete 
 trituration and lixiviation of the several elements. These differences are indicative of 
 long, cold winters, lieav}' snow-fall, and thick ice, but not of glaciation (in this latitude) 
 during the Columbia period. 
 
 The Columbia formation has been traced throughout the greater part of the 
 Coastal plain from the mouth of the Hudson to beyond the Mi.ssissippi, or over an 
 area of more than 200,000 square miles, its thickness and composition varying from 
 place to place with the volumes of rivers and with the character of sediments trans- 
 ported by them ; and the altitudes of occurrences indicate submergence decreasing 
 
 * Defined by McGee in 18S5 ; c. f. American Journal of Science, third series, Vol. XXXV, 
 1888, page 125. 
 
 47 
 
from full}^ 400 feet in the latitude of New York to 150 feet at Washington, and perhaps 
 75 feet in the latitude of Cape Hatteras, thence increasing to nearly or quite 700 feet 
 on the Savannah, diminishing next to less than 50 feet at Mobile bay, and again 
 increasing to variable maxima farther westward and northwestward. 
 
 Traced northward the formation is found to pass under the terminal moraine 
 and the drift sheet it fringes ; at the same time the size of bowlders and other indica- 
 tions of contemporaneous cold multiply, and an element of ice-ground rock flour occurs 
 in the upper member, from which it was long inferred to represent an early episode of 
 glaciation ; and during tbe present summer Salisbury has found it to pass into a pre- 
 morainal drift-sheet in northern New Jersey. From the relative extent of erosion and 
 degree of oxidation, the Columbia formation and the corresponding drift-sheet are 
 inferred to be 5 to 50 times as old as the later glacial deposit, and a rude but useful 
 measure of the duration of the Pleistocene is thus obtained. 
 
 During the post-Columbia period the inner gorge of the Potomac river from 
 Washington to Great Falls was excavated. Anterior to the Columbia period the land 
 stood so high at Washington and northward that the antecedent Lafayette formation 
 was profoundly eroded — indeed, north of the Potomac river only isolated remnants of 
 the I^afayette persist ; but further southward the high level diminished to such extent 
 that the I,afayette formation maintains its continuity over wide areas. This period of 
 erosion was long, yet not so long as to permit planation — deep and broad caiions were 
 carved, to be subsequently converted into estuaries ; ravines were deepened and slopes 
 steepened, and much of the I^afayette formation was degraded ; yet the interstream 
 areas were not reduced to baselevel. 
 
 The Lafayette formation * commonly consists of well-rounded, quartzitic gravel, 
 more or less abundantly imbedded in a matrix of red or orange-tinted loam, the gravel 
 elements predominating in the northwesternmost exposures, and the loam predominat- 
 ing toward the interior of the Coastal plain. The pebbles are evidently derived from 
 earlier members of the elastics ; the loam is derived in part from the same formation but 
 in probably larger part from the residua of the Piedmont crystallines. The deposits 
 differ from those of the younger Columbia formation in that the pebbles are finer, more 
 completely water- worn, and more largely quartzitic ( the Columbia alone containing 
 bowlders and abundant pebbles of the local and sub-local Piedmont crystallines) ; and 
 they may be discriminated from the older Potomac deposits by the smaller size and 
 better rounding of the pebbles, and by the dearth of arkose (which is abundant in the 
 earlier formation), as well as by a number of less striking characters. 
 
 * Described by Safford in 1856 [Geologic Recomiaissance of Tennessee, pp. 14S, 162] and by 
 ^ilt,^^rd in i860 [Geology and Agriculture of Mississippi, p. 3] under the name of Orange Sand ; 
 described by McGee in 18SS [American Journal of vScience, third series, vol. XXXV, p. 328] under 
 the name Appomattox ; formally named Lafayette from original records ( of 1855-56 ) by Hilgard in 
 1891 [American Geol., vol. VIII, p. 129]. 
 
 48 
 
The Lafayette formation, like the Cohunbia, lias been recos^^nized throughout 
 most of the Coastal plain except in the northern portion of the middle Atlantic slope, 
 in the Mississippi valley, and in a nund)er of more restricted areas from which it has 
 been degraded. Its composition varies from place to place in such manner as to indi- 
 cate the local sources of material and conditions of deposition ; yet despite this local 
 diversity it is marvellously uniform throughout the 200,000 square miles over which it 
 has been recognized — indeed, though the youngest member of the clastic series, this 
 formation is at the same time more extensive and more constant in aspect than any 
 other American formation. 
 
 The Lafayette formation overlaps unconformabl}- all the older members of the 
 Coastal plain series in such manner as to indicate that all were extensively degraded 
 anterior to its deposition ; yet the floor on which the formation rests is more uniform 
 than its own upper surface, indicating that, while the antecedent erosion period was 
 long, the land stood low, so that it was planed nearly to baselevel and seldom deeply 
 trenched. During the post-Lafayette elevation, on the contrary, the land was deeply 
 trenched and not planed, indicating a higher altitude than during the earlier eon, but 
 a shorter period of stream work. This record within the Coastal plain proper coincides 
 with a geomorphic record found in the Piedmont and Appalachian zones. Throughout 
 these zones the major and most of the minor rivers flow in broad and deep yet steep- 
 sided gorges excavated in a baselevel plain. The Potomac gorge belonging to this 
 category extends from Washington well toward the sources of the river ; it is within 
 this gorge that the newer Washington-Great Falls caiion is excavated ; the same ancient 
 gorge is admirably displayed at Great Falls, and again at the confluence of the Shenan- 
 doah at Harper's Ferry. Moreover the ancient gorges of this category are best devel- 
 oped in the northern part of the middle Atlantic slope, where the Lafayette formation 
 is most extensively degraded. Now, by the concordance of history thus recorded in 
 plain and plateau, the degradation epochs of the adjacent provinces may be correlated 
 and the ancient gorges of the Piedmont plateau and of the Appalachian zone as well maj' 
 be referred to the period of high level immediately following Lafayette deposition. 
 While the positive evidence for this correlation is liardl}' conclusive, the negative 
 evidence is more decisive — the Coastal plain deposits yield no other record of continent 
 movement of sufficient amplitude and extent to account for this wide-spread topo- 
 graphic feature. 
 
 Accepting the correlation, some conception of the relative antiquit}^ of the 
 Columbia and Lafayette periods nia^^ be formed : In general, post-Lafayette and pre- 
 Columbia erosion was sufficient to remove h\\\y half of the earlier formation through- 
 out its vast extent, and to trench it and the older formations beneath, along the present 
 shore lines of Atlantic and Gulf, to depths ranging from 150 or 200 up to 600 or 800 
 feet, or to effect from 50 to 5000 times the degradation of the post-Columbia period. 
 Again, the post-Lafayette gorges of the Piedmont and Appalachian zones exceed the 
 
 49 
 
post-Columbia gorges excavated by the same rivers in the crystalline rocks certainly 
 not less than 500 times, and perhaps more than 5000 times. Moreover, if the correla- 
 tion 1)e accepted, the immense caiions of the middle Atlantic slope which, albeit more 
 than half filled by later deposits, yet accommodate great estuaries, must be referred to 
 the post-L,afayette high-level, and the p^^gmy submarine trenches of the Atlantic 
 coast * must be referred chiefly, if not exclusively, to the post-Columbia high-level ; in 
 which case the relative erosion measures are many thousands to one. It is indeed 
 known from the steepness of wall of the Piedmont and Appalachian gorges that the 
 excavation was effected rapidl}', and hence that the land stood high above baselevel for 
 a relatively limited period only — a period exceedingly short in comparison with the 
 antecedent period of baseleveling ; and accordingly that the post-Iyafayette high-level 
 may not have persisted, and probably did not persist, to the beginning of the Columbia 
 period. Yet hovvev^er the several variables be evaluated, it is manifest that the pre- 
 Columbia and post-L,afayette degradation interval must have been many times longer 
 than the interval of degradation following the Columbia period. The relative antiquity 
 of the Columbia and I^afayette formations thus indicated is shown graphically in the 
 accompan3'ing figure i . 
 
 
 Lnfiujeite Pteitn\oni Appalnrhiitn. Ottrge-ctUltng Cclumdbi FalUino Ocfge-cuUtngTrmUM 
 
 Prv^LacuU. / a a * 
 
 Prrsent Stta l^vet. 
 
 '-\ / "TT ~-^ 
 
 3z± 
 
 1 EaHy glaci<il. zlnUrt^aciKii ZLat-e glacial -i-RiBt^lacujl 
 
 Fig. I. 
 
 Beneath the Lafayette formation lies the Chesapeake, f a heavy bed of fine sands 
 and clay, sometimes containing more or less abundant glauconite and infusorial remains 
 and characteristic Miocene fossils. This distinctive bed is the most extensively 
 developed member of the Coastal plain series on the "western shore" of Maryland. 
 Although the faunas of the inferior and superior portions are somewhat diverse, the 
 materials of the formation are essentially alike from base to summit, and the faunas 
 intergrade in such manner that it is impracticable to divide the deposits on this ground, 
 at least in the latitude of the National Capital. Although the formation undoubtedly 
 extends eastward to the ocean and both northward and southward for scores or hun- 
 dreds of miles, the deposits have not been actually traced much beyond Delaware Bay 
 on the north and James river on the south. 
 
 Except as modified by the displacement coinciding with the "fall line," the 
 newer deposits sensibly maintain the attitudes of original deposition ; but the Chesa- 
 peake and older formations are slightly deformed. This deformation, best displayed 
 
 * Recently described by Liudenkohl ; Aiiier. Jour. Sci., Vol. XLI, 1S91, pp. 4S9 to 499. 
 t Defined by Darton, Bull. Geol. vSoc. Am. Vol. II, 1890, p. 443. 
 
 50 
 
l)y the surface configuration, is displayed also by the Chesapeake formation ; it con- 
 sists of a slight inclination toward the fall line from an axis api)r()xiniatel>' parallel 
 with and 4 or 5 miles distant from that boundary, together with a somewhat more 
 decided seaward inclination beyond. 
 
 The Chesapeake formation is separated from the Lafayette above and the 
 I Pamunkey below by strong unconformities, each recording considerable degradation 
 of the underlying formations ; but in both cases the inequalities in contact are com- 
 jxaratively gentle, indicating wide-spread planing rather than restricted trenching ; 
 iVom which it may be inferred that the degradation period was long but that the land 
 stood near baselevel. This deposition record of the Coastal plain has been correlated 
 only in a general way with the degradation record of the Piedmont province ; in the 
 latter province the extensive ancient base-level undoubtedly corresponds to several 
 successive periods of Mesozoic and Cenozoic deposition and interruption of deposition 
 in the Coastal plain, of which the Chesapeake period was one. 
 
 The Pamunkey formation * consists of a homogeneous sheet of sand (commonly 
 glauconitic) and clay, with'occasional calcareous layers ; and it commonly abounds in 
 characteristic Eocene fossils. Like the Chesapeake it lies in a gentle anticlinal, its 
 western margin inclining landward, and the great body inclining .seaward. 
 
 Although it has not been actually traced on the ground beyond the limits of 
 the "western .shore" in Maryland, and "tide-water" Virginia, there are good reasons 
 for believing that the Pamunkey formation extends throughout nearly all of the 
 Coastal plain in the middle Atlantic slope, and probably stretches thence southward 
 with unbroken continuity until it merges with the calcareous Eocene series of the 
 eastern Gulf slope. 
 
 The unconformity separating the Pamunkey from subjacent formations is of 
 the planation type, and thus tell, of a long degradation period during which the land 
 was little elevated above baselevel. In general terms this degradation period may be 
 correlated with the baselevel period of the plateau and the mountains ; but there are 
 .some indications that the lifting of the land was greater in the south than in the north. 
 
 The Severn formation f connnonly consists of fine black, micaceous and carbon- 
 aceous sands, sometimes glauconitic, rather poorly fossiliferous, the organic remains 
 beincr of characteristic Cretaceous facies. Southward from the National Capital the 
 formation thins and soon fails ; northward it thickens and expands, undoubtedly pass- 
 ing into the extensive glauconitic Cretaceous beds of New Jersey. Whether the atten- 
 uation southward is due to non-deposition, to extensive degradation in this direction, 
 or to both combined, has not yet been determined. The formation inclines .seaward 
 gentlv, yet more steeply than the Pamunkey ; its extension beyond the gentle anti- 
 
 * Defined by Darton ; Bull. Geol. Soc. Am., vol. 2, 1890, p. 439. 
 t Defined by Darton ; Bull. Geol. Soc. Am., vol. 2, 1890, p. 43S. 
 
 51 
 
clinal axis parallel with the fall line is too slight to give decisive indication of the 
 usual landward dip of this part of the province. 
 
 The floor upon which the Severn formation rests is more uneven than its newer 
 homologues, indicating not only extensive planation but decided trenching, and there- 
 fore may be inferred to represent long-continued degradation of land standing consid- 
 erably above baselevel ; yet the land record of this episode is lost in the remoteness 
 of the period and the feebleness of the record. 
 
 The basal formation of the Coastal plain series (the Potomac *) outcrops along 
 the '■ fall line " from the Delaware to the James as a heterogeneous mass of sand, clay, 
 arkose and qiiartzitic or quartzic gravel. The arkose unquestionably represents the 
 neighboring Piedmont crystallines ; the quartzite is evidently derived from the exten- 
 sive Paleozoic bed forming the Blue Ridge ; the quartz represents the veins by which 
 the Piedmont crystallines are frequently intersected. The more obdurate materials are 
 not, however, confined to the Potomac formation in which they were originally de- 
 posited ; they have been re-arrranged and incorporated with the Lafayette, the Colum- 
 l)ia and probably the Chesapeake formations, and have been accumulated in modern 
 taluses and torrential deposits. Moreover, since the advent of the white man the peb- 
 bles and cobbles have been collected for paving and guttering ; and before his era they 
 were extensively used by the aborigines for the manufacture of rude implements. Al- 
 though not fossiliferous in the District of Columbia so far as known, the Potomac 
 formation has yielded a remarkable fauna and a wonderfully rich and interesting flora. 
 The faunal remains, collected principally between Baltimore and Washington, com- 
 prise dinosaurian bones of unique species but, according to Marsh, strong Jurassic 
 affinities ; the flora, obtained chiefly from Virginia, has been monographed by Fon- 
 taine, by whom it is regarded of Cretaceous facies and probably equivalent to the 
 Cenomanian of Europe, though Ward deems it somewhat older. 
 
 The Potomac formation has been traced southward along the " fall line " in 
 isolated exposures across the Carolinas and Georgia to reappear in considerable volume 
 in Alabama, where it is designated the Tuscaloosa formation, f It has also been traced 
 northward through Maryland and Delaware, and has been recognized in New Jersey. 
 
 The Potomac formation rests unconformably on the Piedmont crystallines, filling 
 steep sided and narrow gorges at low levels, overspreading the moderately undulating 
 plains at high levels. The ancient configuration revealed by this unconformity com* 
 prises an extensive Piedmont peneplain, half reduced to ba.selevel and afterward 
 deeply trenched by the water-ways, much as the smoother baselevel surface of later 
 times was trenched during the post-I^afayette high-level. The duration of the pre- 
 Potomac degradation period was vast : At the close of the Paleozoic the eastern 
 United States was extensively deformed, uplifted and eroded, until many thousand feet 
 
 * Defined by McGee in 1885 ; c. f. jtli Annual Report U. vS. Geological Survey, 1888, p. 546. 
 t Bull. 43, Geol. vSurvey, 1888. 
 
 52 
 
of the surface was carried into the sea ; then came the Newark or Triassic period of 
 local deposition, which was followed in turn by extensive deformation, the faulting 
 amounting probabli' to many thousands of feet ; and tlien followed comparative quie- 
 tude until not only the channels of the water-ways, but the entire surface over some 
 hundred thousand square miles was approximately baseleveled, undoubtedly b\- the 
 degradation of thousands of feet of rock beds. 
 
 This sub-Potomac unconformity gives some indication of the relative position of 
 the Potomac formation in the Meso/.oic period as well as of the relative duration of the 
 several Coastal plain periods of deposition and degradation. L,et post-Columbia erosion 
 represent unity ; then post-Lafayette degradation may be represented ijy kjoo, and the 
 post-Potomac and pre-Lafayette baselevel period may be represented l)y 100,000 ; then, 
 using the same scale, the post-Newark and pre-Potomac erosion must be measured by 
 something like 10,000,000, and the post-Carboniferous and pre-Newark degradation by 
 20,000,000 or 50,000,000. These figures are but rude approximations ; they are more- 
 over in one sense misleading, since degradation undoubtedly proceeded much more 
 rapidly during the earlier eons ; yet they give some conception of the relative imjiort- 
 ance of a long series of episodes in continent growth, and indicate definitively the wide 
 separation of the Newark and Potomac periods. 
 
 
 ^ y ^--^=:;: Z=' 
 
 \ y 
 
 Fig. 
 
 The time relations between the post-Potomac formations are represented graph- 
 ically in the above figure 2. The intervals are of course only rudely approximate, 
 yet they stand for estimates, not guesses. 
 
 THE GEOLOGY OF THE APPALACHIAN ZONE. 
 
 Present State of Knoio ledge. — The general features of this province were long ago 
 made known by the classic work of the Rogers Brothers in Pennsylvania and Virginia ; 
 but since the expansion of the field of geologic science during recent years it has been 
 found necessary to survey in greater detail much of the area already once or twice tra- 
 versed. The Federal surveys of the southern and central Appalachians were for some 
 years in charge of Mr.- G. K. Gilbert, and more recently have been carried on by Mr. 
 Bailey Willis. One of the results of this work has been to raise questions as to the 
 validity of the early correlation of the central Appalachian series with that of New York, 
 except in a general way — the great groups of New York are indeed known to occur 
 throughout the Appalachian province, yet the minor subdivisions with their distinctive 
 
 53 
 
faunas are found to undergo modification of such character and extent as to indicate 
 that identity in each particular case can be determined onl}^ by more extended and de- 
 tailed studies than have thus far been made. Another result has been the discrimina- 
 tion and delimitation of certain well-defined formations in Virginia, West Virginia, 
 Maryland, Tennessee, North Carolina, Georgia and Alabama ; but the rocks of a con- 
 siderable part of the province remain to be classified in accordance with the modern 
 method. For the present it will suffice to say that an essentially complete American 
 Paleozoic series of rocks is represented in the province. 
 
 The Origin and Relations of the Rocks. -'^ — The Appalachian Paleozoic province 
 is characterized by the occurrence of sediments deposited in the Mediterranean sea of 
 North America, which existed during the lapse of time from the early Cambrian to the 
 close of the Carboniferous period. It is bounded on the north and east by ancient 
 crystalline rocks, the bases of a great mountain system, now deeply eroded, and the 
 remains of a continent whose former extent is only to be inferred from the enormous 
 volume of sediments it yielded to the Paleozoic sea ; and on the south and west, Meso- 
 zoic and Cenozoic deposits limit our observation of the older strata. 
 
 The history of subsidence and uplift of erosion and sedimentation may be sum- 
 marized as follows : 
 
 Cambrian : The invasion of the sea, which began the known deposits of 
 Cambrian strata along the Appalachian crystalline area, found a continent mantled in 
 the products of rock disintegration.! These materials, easily swept away, produced 
 a mass of fine sandstones and shales, and near the source they retained fragments of 
 feldspar, hornblende, and other minerals, which gave rise to transition beds between 
 the clearly crystalline and the clearly sedimentary rocks. lyimestones formed where 
 the mechanical debris was not too abundant, and the result is a complex of deposits 
 measuring 7,000 feet and more in thickness. The uppermost member is the Potsdam, 
 a sandstone in its typical locality, elsewhere a shale or a limestone carrying the char- 
 acteristic upper Cambrian fossils. ;{: 
 
 Lower Silurian : This period is divided into two epochs, separated by an inter- 
 val of erosion of the earlier member. The conditions of deposition continue generally 
 unchanged from Cambrian into Silurian time, the principal result being a great thick- 
 ness of chert-bearing dolomite. This formation is the most widespread, the most 
 uniform and the most massive of all the Paleozoic series. From Massachusetts and 
 New York to Alabama, and westward under the Mississippi valley, it is everywhere 
 the great limestone member of the stratigraphic column. It is usually 3,000 to 4,000 
 feet thick. This phase of deposition was closed by an uplift, which permitted the 
 
 * By Bailey Willis. 
 
 t Punipelly, R., "Secular Rock Disintegration, etc." Bull. Geol. Soc. Am., Vol. II. 
 
 X WalcoU, C. D., Cambrian Faunas, Bull. 30, U. S. Geol. Survey. 
 
 54 
 
formation of wave-wrouf^ht conglomerates and sea-cliff debris from the limestone along 
 
 the coast line in Tennessee and in Massachnsetts, and probabl}' throiighoul the entire 
 
 interval where detailed search has not been made. This brings us about to the close 
 
 of the New York Trenton formation. 
 
 The .second epoch began with the transgression of the sea, and continued until 
 
 the coast line of the Cambrian ocean had been submerged. The cojiditions of the 
 
 source of sediments were precisely like those that existed during the Cambrian, and a 
 
 very similar series of conglomerates and .sandstones were formed. The submergence of 
 
 the land was deeper than any that preceded or followed it ; sediments to a depth of 
 
 1,200 feet accumulated locally and thinned out westward to a few hundred feet. A1)out 
 
 Cincinnati they are represented by the highly fossiliferous shales and limestones of that 
 
 name. 
 
 Upper Silurian : The preceding period closed with an uplift, which is possibly 
 
 contemporaneous with the unconformity locall}^ evident in the northeastern province. 
 
 The first deposit of the Upper Silurian is a widespread sandstone, of j^eculiarly clean 
 
 character, followed by the ferruginous shales of the Clinton formation, which contain 
 
 the important fossil iron ores. The later history of the period is recorded in limestones, 
 
 the Niagara, Salina and Helderberg, which are best represented in New York, Penn- 
 
 .sylvania and Ohio, and thin out or disappear southward. 
 
 Devonian : In the Oriskany calcareous sand.stone, followed by the Corniferous 
 limestone in New York, we hav^e a lithologicall}^ variable horizon, which contains 
 fo.s.sils of both Upper Silurian and Devonian types, and marks the transition from con- 
 ditions favoring the deposit of impure limestones of the Silurian to the great subsidence 
 under the load of mud and sand deposited over New York, Penn.sylvania and Virginia 
 during the Devonian. The lowest member of this series is a highly bituminous .shale, 
 the most persistent of all Paleozoic formations except the great limestone, although in 
 Tennessee and Alabama it is often not over 20 feet thick. In Pennsylvania it exceeds 
 500 feet, and in New York the formation reaches 1,200 feet. Above these dark shales 
 follow greenish argillaceous sandstones, succeeded by red shales and sandstones. The 
 total thickness of these mechanical deposits exceeds 8,000 feet in northern Virginia, 
 but they thin out rapidly southward, and are not clearly recognized in Tennessee. 
 
 Carboniferous : The mechanical sediments of the Devonian are overlain by beds 
 of limestone, which are sometimes .shaly, sometimes massive and chert-bearing. Above 
 these are the sandstones and conglomerates at the ba.se of the coal measures, deposits 
 of coarse materials spread over a vast area during a single epoch. Then ensued the 
 conditions of alternating sea and marsh, which built up to a thickness of 3,000 to 4,000 
 feet the mass of sandy shales, shales, limestones and coal beds of the Appalachian coal 
 
 field. 
 
 The Appalachian Structure .^'^ — It has long been the assumption that the deforma- 
 tion of Paleozoic sediments in the Appalachian province took place at the clo.se of the 
 
 * By Bailey Willis. 
 
 55 
 
Carboniferous period. That certainly was the time of greatest development of folds 
 and faults, but there is good reason to believe that there were initial disturbances as 
 far back as the Trenton period. The forms of structure called "Appalachian," and 
 often referred to as a single type, differ greatly in different regions. But they are all 
 manifestations of one phase of deformation, namely, compression. A belt of strata ex- 
 tending along the old shore line from Canada to Alabama has been narrowed in a 
 direction perpendicular to that shore by a reduction to five-sixths or four-fifths of its 
 undi.sturbed width. This compression, which probably went on at several epochs dur- 
 ing the Paleozoic age, raised long narrow arches with intermediate troughs (anticlines 
 and synclines), and in some localities pressed these folds till they closed upon them- 
 selves. The force also produced movements (faults) along planes of weakness devel- 
 oped in the folding mass, movements which sheared across strata opposed to them in 
 such a wa>' as to slide older and deeply buried formations over the edges of younger 
 deposits. Thus a geologic map of the Appalachian province usuall}' represents many 
 narrow parallel belts of strata in some regions, such as Pennsylvania and Virginia, 
 winding around alternating anticlinal and synclinal axes ; in other districts, such as 
 Tennessee, extending for scores of miles adjacent to a continuous fault line. 
 
 The history of Mesozoic and Cenozoic time is recorded in the Paleozoic province 
 in geographic forms, in mountains, baselevel plains and river systems. What we have 
 thus far read of this history is explained elsewhere. 
 
 The; Local Geoi^ogv. 
 crystali.ine rocks of washington.* 
 
 General Features. — The entire area covered by the Washington atlas-sheet is 
 composed of the crystalline rocks of the Piedmont plateau. These are, however, con- 
 cealed in the eastern and southern portions of this area by the comparatively thin 
 covering of Coastal plain deposits, from whose irregular and sinuous western edge they 
 emerge to form the surface. Satisfactory exposures of these rocks are to be found only 
 in the deep ravines cut by the streams (e. g. the Potomac and Rock Creek or their 
 tributaries), since at the surface of the plateau their character has been obscured or 
 obliterated by extensive superficial decay and by cultivation. 
 
 The older rocks of the Washington sheet belong entirely to the eastern or holo- 
 crystalline portion of the plateau province, as already described. They are for the most 
 part granitoid gneisses of varying composition, which grade into wholly massive 
 varieties of probably eruptive origin on the one hand, while they retain occasional 
 evidence of clastic origin (obscure conglomeratic layers) on the other. Toward the 
 west, as displayed along the Potomac section, which is nearly transverse to their 
 strike, these rocks become somewhat more foliated and schistose as they approach the 
 
 * By George H. Williams. 
 
 56 
 
bouiularv of tlic western or senii-cryslalliiie area wliicli passes near (ireal Kails in the 
 extreme northwestern corner ()f the sheet. There are also nnicli larther east occasional 
 l)ancls of very schistose rock (notably those seen alont; Ihoad liraiich) which i)ass 
 indiscriminately from one formation to another, and which owe their present character 
 to nnnsually intense dynamic action. 
 
 The final period of orogenic disturbance which imparted to the entire Piedmont 
 plateau, in common with the Appalachian system, its present structure, gav^e to the 
 crystalline rocks within the Washington sheet a north-south strike. The occasional 
 faint evidences of original bedding that have survived within this area .seem now to 
 accord closely with the foliation which has been developed in all the r(jcks, igneous 
 and clastic alike, during the extreme metanu)r])hism to whicli the>- have been sub- 
 jected. This is a dip almost constantly to the west within the entire area, and growing 
 more and more steep toward the west, in accordance with the general structure of the 
 Piedmont plateau, as explained in a preceding section. Only in the extreme north- 
 western corner of the sheet, near Great Falls, do the rocks begin to incline very 
 steeply toward the east. 
 
 Leading Rock Types. — A partial examination (still in jn-ogress) of the crystal- 
 line formations within the the limits of the Washington sheet has brought to light the 
 following easily distinguishable rock types, which are provisionally enumerated, 
 although it is probable that further study will both modify and enlarge the list. 
 
 Granite, Granite-Gneiss ami Gneiss ; Ouart/.-Orthoclase-Mica Rocks : This is 
 by far the most extensively developed of all the cr\stalline formations of the area in 
 question. It embraces undou1)tedly eruptive granite, secondarily foliated (stjueezed) 
 granite, and t3-pical gneiss, probably metamorphosed .sediments. On account of their 
 close lilhological resemblance, decayed condition, and concealed contacts, these rocks 
 cannot however at present be accurately subdivided on the map. Hence they are rep- 
 resented by a single color. Toward the east, notably along Sligo and Piney branches, 
 the.se rocks are v^ery massive, often quite devoid of any foliation, and are not infre- 
 quently filled with inclusions of other rocks in which characteristic granite contact 
 minerals are largely developed. All this points to an eruptive origin, and these char- 
 acters persist even where a secondarj^ foliation has been developed in accord with the 
 prevailing strike and dip. P'arther westward the rocks appear more like typical 
 gneisses, being banded, more micaceous and more schistose. Apparent beds of con- 
 glomerate have also been noticed in them along the south bank of the Potomac river, 
 and near the Klingle Ford bridge over Rock Creek. 
 
 Diorite : Massive, dark green amphibole-biotite-granite. — These rocks present 
 a marked contrast to the last tj^pe in their dark color. They always contain green 
 hornblende, biotite, orthoclase and plagioclase, sometimes one and sometimes the other 
 in excess. Quartz is also usually present and not infrequently rutile, sphene and 
 epidote as well. I'^nder the microscope they generally show evidence of profound 
 
 57 
 
dj-namic action. In all probability they represent ancient eruptive masses which have 
 been subsequent!}'' greatly changed and recrystallized by earth-movements. They are 
 most extensively developed around Georgetown and near Cabin John. In quarries at 
 the former place clearly defined inclusions of other rocks have been noticed, which 
 substantiate the theor}- of their eruptive origin. 
 
 Serpentine and Steatite : A few small lenticular areas of serpentine and soap- 
 stone occur within the area under consideration. They are usually closely associated 
 with the more basic hornblendic rocks, and are, probably, like these of eruptive origin, 
 although this hypothesis cannot as j-et be considered as definitely proved. 
 
 Gabbro : Two small elongated exposures, presumably dikes, of trap-like rocks, 
 which the microscope shows to be in all respects identical with the Baltimore hypers- 
 thene-gabbro,* occur near West Falls Church station, but have been as yet noticed 
 nowhere else within the Washington region. 
 
 Broad Branch Schists : On the road leading northward from the Pierce Mill road 
 along Broad Branch, a narrow band of thinly foliated sericitic, chloritic and siliceous 
 schists is exposed. These rocks differ considerably in character and appearance from 
 those about them, but still they grade imperceptibly into the granite and gneiss which 
 lie both on their eastern and western sides. The belt, although quite narrow, has a 
 considerable extent from north to south in the direction of its strike. Under the micro- 
 scope all of these schists show evidence of the most extreme dynamic action. Their 
 distinguishing characters (mineralogical composition, foliation, etc.) are clearly second- 
 ary ; and they may readily have been produced by an unusual amount of compression 
 brought to bear on the normal material of the granite or gneiss, This schist belt is 
 therefore probably the result of extraordinary pressure at the axis of a closed synclinal 
 fold, rather than the product of metamorphism of beds originall}- distinct from those 
 around them. 
 
 Siliceous Gneisses and Schists of Great Falls : The barrier at the Great Falls 
 of the Potomac is an unusually siliceous, and therefore unusually hard, band in, the 
 gneiss. In some places this rock is so siliceous that it contains hardly anything 
 except quartz and mica, and thus becomes a quartz schist. It exhibits throughout 
 definite microscopic evidence of having been subjected to great pressure. 
 
 In spite of the considerable variet}' showai b}- this list, the crj'Stalline rocks near 
 Washington are much more uniform and monotonous than those forming the eastern 
 part of the Piedmont plateau farther northward. This is particularly the case with 
 the eruptives. The gabbros and gabbro-diorites, .so abundant near Baltimore, f in 
 Harford County, Maryland, and in northern Delaware,;}: are represented by only one 
 
 * Bull. U. S. Geol. Survey, No 28. 
 
 t Bull. U. S. Geol. vSurvey No. 28, by George H. Williams. 
 
 t Bull. U. S. Geol. Survey No. 59, by F. D. Chester. 
 
 .S8 
 
very insigiiificaut occurrence near Falls Churcli, Virs^inia, on the Washinj^lon sheet ; 
 while the various peridotiles, pyroxenites and derived rocks ''= are altogether absent. 
 
 Granitic rocks are largely developed near Washington, and many of them pre- 
 serve, both in their massive character and included fragments, fair evidence of eruptive 
 origin. Nevertheless even these are far inferior in petrographic variety and interest 
 to the undoubtedly intrusive granites, granite-porphyries and felsites occurring farther 
 northward in Maryland. 
 
 CLASTIC FORMATIONS OF WASIIINGTON.t 
 
 The General Structure. — In the vicinity of Washington the formations <jf the 
 Coastal plain series are extensively displayed, and all the principal members are 
 characteristically developed. The general structural relations are illustrated in the 
 accompanyiug figure 3. 
 
 C/a-.VEUMJtt: IUHTI.1 
 
 
 ^''g^- 3- — General cross-sectiou through the central portion of the Washington atlas-sheet. 
 
 The Potomac formation lies on the steeply-sloping surface of the crystalline 
 rocks, and is overlain by the gently eastward-dipping Severn, Pamunkey and Chesa- 
 peake formations in regular succession, upward and eastward. The I^afayette forma- 
 tion caps the higher plains and the Columbia formation occupies the lower terraces. 
 The regular succession is interrupted locally in the ridge east of Washington where 
 tlie Pamunkey formation overlaps the Severn for a few miles, and is in turn overlapped 
 by Chesapeake beds which lie directly on the Potomac formation in small outliers 
 north and west of Washington. These formations also thicken seaward, each with 
 slightly increased rate from below upward, and their separating planes of unconformity 
 incline gently eastward. The Lafayette formation lies across the planed surfaces of 
 the successive formations from the crystallines westward to the Chesapeake formation 
 eastward. The Columbia formation lies on terraces cut in the crystallines and in the 
 Potomac, Severn, Pamunkey and Chesapeake formations from tide level to about 150 
 feet above. 
 
 A line of dislocation extends from northeast to southwest across the western 
 half of the Washington atlas-sheet. The downthrow is on the eastern side and 
 amounts to from 50 to 100 feet. This fault traverses the Lafayette and Potomac form- 
 ations and the crystalline rocks, and in the divides its presence is marked by an escarp- 
 ment of crystalline rocks, usually capped l)y Potomac and Lafayette deposits. The 
 
 * Am. Geol., July, 1890. 
 fBy N. H. Darton. 
 
 59 
 
date of the movement was mainly between the Lafayette and Columbia, but apparently 
 some movement has taken place since the deposition of the Columbia. 
 
 The Cohinibia Formation. — The lower terraces of the Potomac valley and its 
 larger branches and the valley of the Western Branch of the Patuxent are occupied 
 by the Columbia formation up to altitudes varying from So to 145 feet. About the 
 cit)^ or Washington the more general Columbia terrace levels are at 40 and 80 feet 
 respectively above tide ; the Capitol being situated on the western edge of a prominent 
 outlier of the 80-foot terrace. The formation exhibits its typical development in the 
 District of Columbia, where it consists of two members ; a lower series of gravels and 
 an overlying brown or buff loam. The gravels are heterogeneous in character, com- 
 prising remains of the more obdurate material of preceding formations, in large part of 
 local origin. The loams are often quite pure, but they are frequently intermixed with 
 sand and pebbl}' streaks and disseminated pebbles. Southward from Washington the 
 Columbia terraces border the Potomac river to widths of from one to two miles, and the 
 materials as a whole become finer. In the Anacostia valley the formation consists 
 mainly of brown sands with pebbly streaks, but at Washington these sands merge into 
 the loams and gravels of the typical phase. Along the northern side of the Washing- 
 ton-Great Falls gorge of the Potomac there is a narrow shelf at 145 above tide, 
 which is capped at intervals by Columbia loams and gravels. The thickness of the 
 Columbia formation about Washington averages from 20 to 30 feet. 
 
 The Lafayette Formation. — This formation occupies portions of the wide, high 
 plains surrounding the Washington amphitheater, especially toward the south and 
 southeast. Its materials are mainly gravels and loams. The basal and marginal beds 
 are in larger part gravels, usually stained buff or orange, superficially, and packed 
 tightly in stiff loams and sharp sands. The upper beds are predominantly loamy, and 
 farther eastward loams and fine sands with gravel streaks prevail. In the outliers 
 north and west of Washington the formation consists of gravelly red loams. The plain 
 on which the Lafayette formation was deposited is depressed by a wide shallow basin 
 in which is excavated the present Potomac valley below Washington. This old basin 
 gives rise to a series of lower Lafayette terraces adjoining the Potomac valley, the prin- 
 cipal area of which is in the vicinity of the St. Elizabeth Asylum, where its elevation 
 is 160 to 180 feet. The Lafayette formation extends for some distance west of the 
 " fall line " fault in a series of outliers, usually with underlying remnants of the 
 Potomac. 
 
 The Chesapeake Foi'viation. — This formation underlies the high plains southeast 
 of Washington, where it is overlain by a capping of the Lafayette formation over the 
 greater part of its area. The formation extends to the edge of the high bluffs east of 
 Washington, and also is caught in small outliers of the higher terrace-levels at Soldiers' 
 Home Park, and between West Washington and Tennallytown. The formation con- 
 sist of very fine grained materials, mainly sands, with a variable proportion of infusorial 
 
 60 
 
remains and clay. In Ihcir unwcalhcrcd condition llie beds are nsnallj' \'cry compact, 
 dark gray to olive-green in color, and massively bedded. Surface outcro])s consist of 
 soft meal-like sands of light buff color. Some clay beds occur, notably locally in the 
 eastern part of the District. Infusorial remains are nearly everywhere present, and 
 faint casts of mollu.scan remains are generally abundant in the unweathered material. 
 The outliers in the ridges about Washington consist of ])uff-colored, meal-like beds, 
 lying on an irregular surface of the Potomac sands, and in turn overlain by I^afayette 
 gravels. The thickness of the formation increases gradually eastward and is about 125 
 feet in the Marlborough region. 
 
 The Pamunkcy Formation. — The Pamunkey formation occupies a wide area east 
 of Washington, and is a conspicuous member of the Coastal plain series in this region. 
 In its unweathered condition the formation is mainl}' a bluisli or greenish-black marl, 
 consisting of fine-grained (|uartz sands mixed with varying amotmts of organic matter 
 and clay, and usually containing a considerable proportion of the mineral glauconite. 
 On weathering the glauconite is' decomposed, and its iron constituent oxidizes and 
 stains the sands to a dull red brown or snuff color. The weathered phase is general 
 on the surface in the regions in which the formation has long been bared of overlying 
 formations. In the streams leading out of the high plains east of Washington the 
 unweathered marls are often exposed, and in the region to the northwestward the 
 formation is bare for many scpiare miles. P^ossil shells frequently occur in great abund- 
 ance in the marls, and there are many ])rolific fossil localities within a few miles of the 
 city of Washington. 
 
 The thickness of the formation increases eastward from two to five feet in the 
 ])luff just east of Washington to over 100 feet in the Marlborough region. 
 
 The Sei>c7-n Formation. — In the vicinity of Washington this formation is a thin 
 bed of l)lack sands, lying between the Potomac and the Pamunkey formations east of 
 the Potomac and the Anacostia rivers. It is the attenuated southern extension of the 
 great Cretaceous green-sand formation of New Jersey and Delaware ; but in this region 
 it consists mainly of fine carbonaceous, more or less argillaceous, sands containing 
 small scales of mica, but very little glauconite. It usually abounds in casts and 
 impressions of distinct Cretaceous fossils ; and fossil .shells occur in abundance at 
 several localities. In the bluff east of Washington it is locally cut out by an overlap 
 of the Pamnnkey formation, but it conies in again toward the northeast with a thick- 
 ness of 20 or 30 feet, and is occasionally exposed in streams and road-cuts throughout 
 the eastern portion of the Washington atlas-sheet. 
 
 The Potomac Formation. — The Potomac outcrops occupy a wide area in the 
 vicinity of Washington, especially to the .sonthwestward. In Wa.shington and the 
 Potomac estuary the formation is generally hid beneath the Columbia formation, and 
 in the plateaus toward the southwest the Lafayette formation covers it extensively. 
 The deposits consist mainly of clays and sands of light color, commonly most irregu- 
 
 61 
 
larly intermixed. The basal beds exposed along the western margin are mainly gray 
 sandy arkose, with pebbles and ])owlders. In Virginia the sandy arkose and arkosic 
 sands give place eastward to gray, greenish, brown and buff sandy fissile clays. 
 North of the Potomac they grade upward into a great series of fine quartz sands and 
 clays, the argillaceous elements increasing in proportion eastward. Along the Balti- 
 more and Potomac railroad, and thence eastward to the Severn formation, the clays are 
 extensively developed, and the sands occur as locally indurated sheets and crusts, or 
 more rarely intermixed with the clays. The formation attains a thickness of over 300 
 feet east of Washington, but it is eroded westward finally to a feather edge. 
 
 Post-Cohinibia Deposits. — The overwash deposits on slopes and along the smaller 
 streams as well as the river muds and marshes, and the freshet deposits along the larger 
 rivers are post-Columbia in age ; but owing to their relative unimportance they are not 
 represented on the present edition of the geologic map. As the rivers are submerged 
 and sinking, and the present area of submergence was preceded \>y erosion, alluvial 
 deposits are mainly under water in the Washington'' region and consist of river muds, 
 and the freshets are small in volume. 
 
 Artificial. — The tidal marshes adjoining the southern part of Washington have 
 been built up above tidal level with materials obtained by excavations from the ad- 
 joining channels. This area is represented on the map as artificial. 
 
 The Geomorphology. 
 
 During recent years certain geologists have come to recognize that within 
 certain limits earth history may be read from the land-forms developed by degradation 
 as well as from the strata formed by concurrent deposition ; and the Coastal Plain and 
 contiguous provinces of eastern United States are so conditioned that these lines of 
 research may be successfully prosecuted within them. 
 
 Although the parallel mountain ranges are the most conspicuous features of the 
 Appalachian province, the broad gently undulating intermontane plains are only less 
 conspicuous and far more extensive ; and only less conspicuous than the intermontane 
 plains are the narrow steep-sides gorges of all water-ways incised within the plain and 
 sometimes notching mountains — indeed, the entire province is really an undulating 
 baselevel plain with ranges embossed upon it, and with a series of wide-branching 
 drainage system sharply inscribed within it. 
 
 The most conspicuous and extensive feature of the Piedmont zone is the far- 
 stretching peneplain or undulating baselevel plain comprising the greater part of its 
 area ; only less conspicuous are the narrow steep-sides gorges in which its water-ways 
 flow. The Piedmont plain thus homologizes the Appalachian province with respect 
 to classes of features ; but the embossed mountains are lacking. 
 
 Although the most conspicuous configuration of the Coastal plain is that of the 
 present surface there are in this province a series of configurations characterizing a 
 
 62 
 
number of ancient surfaces, each of which is a p;reat stratigraphic unconformity ; and 
 the researches in this region have progressed so far that the general characters of each 
 of these surfaces have been ascertained. The present surface is a terraced lowland, 
 trenched by broad yet shallow estuaries and partly dissected by minor water-ways flow- 
 ing in narrow steep-sides channels, produced by rapid excavation ; but portions of the 
 lowlands are not yet invaded by the minor drainage. In general the surface is water- 
 carved, and represents sluggish trenching along drainage lines. The next older surface 
 (the contact surface between the Columbia and the Lafayette) is the most strongly 
 accented of the province ; it represents a peneplain strongly and deeply trenched but 
 nowhere planed to baselevel, save possibly in the deeper gorges far below the reach of 
 observation. The next lower surface (the Lafayette-Chesapeake surface) is smoother 
 than that of the present, and the configuration as well as the relations of structure to 
 that configuration indicate widespread baselevel planation with little trenching along 
 the water-ways. The next surface ( the Chesapeake-Pamunkey ) is similar, but even 
 smoother. The Pamunkey-Severn surface in like manner is smooth and .so related to 
 the structure as to tell of extensive planation without localized vertical cutting. The 
 Severn-Potomac surface on the other hand is decidedly rugose, and its relations to 
 structure are such as to indicate that it represents a peneplain extensively degraded, 
 yet chiefly along the drainage lines. The baselevel surface upon which the entire 
 series of Coastal plain deposits rests — the sub-Potomac floor — is much like the present 
 Piedmont surface, i. e., a rather .strongly undulating peneplain, trenched by deep-cut 
 gorges. 
 
 In addition to these general features of the three provinces there are a multitude 
 of minor features, of which a portion have been studied and interpreted. Thus Chani- 
 berlin and Gilbert as well as White in the western part of the mountain province, and 
 McGee in tlie eastern part of the same province, as well as in the plateau, have a.scer- 
 tained that the early Pleistocene deposits rest on the great Appalachian-Piedmont 
 peneplain ; Willis has traced the same or a remarkablj^ similar peneplain into the 
 southern Appalachians in North Carolina ; Davis * has recently recognized and admira- 
 bly described an ill-defined pre-Tria.s.sic and well defined pre-Cretaceous peneplain in 
 New England and the northern Appalachians ; Emerson has incidentall}' developed 
 certain features of a pre-Triassic land surface in New Etigland ; and by these and other 
 researches several iinportant features in thegeoniorphic history of ea.stern LTnited States 
 have been elucidated. It is known that the drainage and the topographic forms result- 
 ing therefrom in the Appalachian zone were developed by orogenic movement and are 
 therefore tectonic, they are certainl}' consequent in the western part of the province, 
 and probably antecedent in the eastern part ; it is known that much of the drainage 
 
 *Bull. Geol. Soc. Am., Vol. II, 1891. 
 
 63 
 
and configuration of the Piedmont plateau is of the subsequent type, depending upon 
 planation and measurably reflecting rock composition, and also that another part is 
 superimposed ; and it is known that while the principal drainage lines of the Coastal 
 Plain are affected by relatively recent deformation the greater number of the streams 
 and of their land-formed progeny belong to a series of autogenetic systems, repeatedly 
 yet concordantl}- superimposed. 
 
 The episodes thus recognized blend as a consistent and essentially complete 
 series of continent movements indelibly recorded in the land forms of the mountains, 
 the plateau, and the lowland. The series begins with the faintly recorded incomplete 
 baselevel of the pre-Triassic time ; this shadowy record is followed by the more defin- 
 ite one (at least in the latitude of Washington) of a long baselevel period, followed by 
 a brief high level period during which the land first tilted seaward and then sank until 
 the Potomac deposits were laid down ; next follows the extensive record of that long 
 baselevel period which Davis stj'les " pre-Cretaceous, " though it maybe questioned 
 whether this record does not merge w-ith that of the pre- Potomac episode on the one 
 hand and that of the long post-Cretaceous baselevel period on the other ; then follow 
 the series of alternating episodes of sluggish deposition and indolent degradation 
 recorded in the Severn- Pamunkey and Chesapeake formations, with their intervening 
 unconformities — a series of episodes which may not be discriminated in the 
 faintly inscribed record of the ancient Piedmont and Appalachian baselevel ; 
 afterward follows the well defined episode of high level recorded in the Piedmont- 
 Appalachian gorges and in the broad and deep trenches through which half 
 the volume of the Lafayette formation was carried into the sea ; and then follows the 
 inconspicuous but easily legible record of the Columbia submergence and the post- 
 Columbia emergence — the former certified b)' the semi-filling of the ancient canons, the 
 latter by the shallow submarine channels and the pygmy " fall-line " gorges ; finally, in 
 the northern part of the Coastal plain comes the record of submergence and subsequent 
 lifting during the later ice invasion. This long series of generally consistent land 
 movements is complicated in the middle Atlantic slope by the displacement, probably 
 beginning in the Lafayette period and certainly continuing to-day ; but properly inter- 
 preted this complication only affords a check upon the accuracy of the general reading. 
 
 64 
 

 
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