ADVERTISEMENT. IX 



18. Irrigafion near Fresno, Calit'orriia, by C. E.Grunsky. 1898. S°. 94 pp. 14 pi. 



19. Irrigation near Pierced, California, l)y C.E. Gruusky. 1899. 8=. 59 ii|>. 11 iil. 



20. Hxperinient.s \vitli AVindniill.s, liy T. O. Perry. 1899. 8°. 97 pp. 12 pi. 



21. AVclls of Northern Indiana, by Frank Leverett. 1899. 8^. 82 pp. 2 pi. 



22. Sewage Irrigation. Part II. by (ieorse"\V.i;after. 1899. 8-. lUU pp. 7 pi. 



23. "WaterriLrlit I'robleiMs of the Biuliorn Moiintain.s, by Elwood Mead. 1899. 8°. 62 pp. 7 pi. 



24. Water Kesources of the State of Xew York, Part I, by G. "\V. Itafter. 1899. 8^. 99 pp. 13 pi. 



25. Water Resources of the Stale of Xew York, Part II, by G.W.Kafter. 1899. 8°. 101-200 pp. 12 pi. 

 20. AVells of Southern Indiana (Continuation of No. 21), by Frank Leverett. 1899. 8°. 64 pp. 



27. Operations at River Station.-^ for 1808, 1'art I. 1899. 8^. 100 pp. 



28. Operations at River Stations for 189S, Part II. 1899. 8=. 101-200 i)p. 



29. AVells and Windmills in Nebraska, by Krwin H. Barbour. 1899. 8^. 85 pp. 27 pi. 



30. Water Resources of the Lower Peninsula of Michigan, by Alfred C.Lane. 1899. 8=. 97 pp. 7 pi. 



31. Lower Michigan Mineral Waters, by Alfred C.Lane. 1899. 8". 97 pp. 4 ).l. 



32. Water Resources of Puerto Rico, by Herbert M. Wilson. 1899. 8^. 48 pp. 17 pi. 



33. Storage of Water on Gila River, Arizona, br Joseph B. Lippincott. 1900. 8°. 98 pp. 33 pi. 

 .34. Geolojiy and water resources of SE. South Dakota, by J. E. Todd. 1900. 8=. 34 pp. 19 pis. 



35. Operations at River Stations, 1899, Part I. 19iiU. 8^. 100 pp. 



3C. Operations at River Stations, 1899, Part II. 1900. 8=. 101-198 pp. 



37. Operations at River Station.s, 1899, Part III. 1900. 8=. 199-298 pp. . 



38. Operations at River Stations, 1899, Part IV. 1900. 8=. 299-390 pp. 



39. Operations at River Stations, 1899, Part V. 1900. 8=. 397-471 pp. 



TOPOGRAPHIC .MAP OF THE UNITED STATES. 



When, in 1882, the Geological Survey was directed by law to make a geologic map of the United 

 States, there was in existence no suitable topographic map to serve as a base for the geologic map. 

 The preparation of such a topographic map was therefore immediately begun. About one-fifth of the 

 area of the country, excluding Alaska, has now been thus mapped. The map is published in atlas 

 sheets, each sheet representing a small i|uadrangular district, as ex])lained under the next heading. 

 The separate sheets are sold at 5 cents each when fewer than 100 cojiies are purchased, but when they 

 are ordered in lota of 100 or more copies, whether of the same sheet or of different sheets, the price is 

 i cents each. The mapped areas are widely scattered, nearly every State being represented. About 

 900 sheets have been engraved and printed; they are tabulated by Stales in the Survey's " List of 

 Publications,'' a jiamphlet which may be had on application. 



The map sheets rejiresent a great variety of topographic features, and with the aid of descriptive 

 text they can be used to illustrate topographic forms. This has led to the projection of an educational 

 series of topographic folios, for use wherever geography is taught in high schools, academies, and 

 colleges. Of this series the first two folios have been issued, viz: 



1. Physiographic types, by Henry Gannett, 1898, folio, consisting of the following sheets and 4 pages 

 of descriptive text: Fargo (N. Dak. -Minn.), a region in youth; Charleston (W- Ya.), a region in 

 maturity; Caldwell (Kans.), a region in old age; Palmyra (Va.), a rejuvenated region; Mount Shasta 

 (Cal.), a young volcanic mountain; Eagle (Wis.), moraines; Sun Prairie (Wis.), drumlins; Donald- 

 sonville (La.), river flood plains; Boothbay (Me.), a fiord coast; Atlantic City (N. J.), a barrier-beach 

 coast. 



2. Physiographic types, by Henry Gannett, 1900, folio, consisting of the following sheets and 11 pages 



of descriptive text: Norfolk (Ya.-N. C), a coast swamp; Marshall (Mo.), a graded river; Lexington 



(Nebr.), an overloaded stream; Harrisburg (Pa.), Appalachian ridges; Poteau Mountain (Ark.-Ind. 



T.), Ozark ridges; Marshall (Ark.), Ozark Plateau; West Denver (Colo.), hogbacks; Mount Taylor 



(N. Mex.), volcanic peaks, plateaus, and necks ; Cucamonga (Cal.), alluvial cones ; Crater Lakespecial 



(Oreg.), a crater. 



GEOLOGIC ATLAS OF THE UNITED STATES. ^ 



The Geologic Atlas of the United States is the final form of publication of the topographic and 

 geologic maps. The atlas is issued in parts, or folios, progressively as the surveys are extended, and 

 is designed ultimately to cover the entiie country. 



Under tlie plan ado])ted the entire area of the country is divided into small rectangular districts 

 (designated qnadrawilrs), bounded by certain meridians and jiarallels. The unit of survey is also the 

 unit of publication, and the majjs and descri])tions of each rectangular district are issvied as a folio of 

 the Geologic Atlas. 



Each folio contains topographic, geologic, economic, and structural maps, together with textual 

 descriptions and explanations, and is designated l)y the name of a i)rincipal town or of a prominent 

 natural feature witliin the ilistrict. 



Two forms of issue have been adopted, a 'library edition" and a "'field edition." In both the 

 sheets are bound between heavy paper covers, but the library copies are permanently bound, wliile 

 the sheets and covers of the field copies are onlj" temporarily wired together. 



Under the law a copy of each folio is sent to certain pul)lic libi'arics and educational institutions. 

 The riMuainder are sold at 25 cents each, except such as contain an unusual amount of matter, which 

 are priced accordingly. Prepayment is obligatory. The folios ready for distribution are here listed. 



Bull. 173 13 



