438 



NATURE 



[March 12, 1896 



work. It was found that large tracts of country were 

 unmapped, or else that such maps as did exist were 

 worthless for geological purposes ; so the Survey set 

 itself to produce the necessary maps, and a very con- 

 siderable advantage is likely to accrue to the country 

 from the two types of survey being directed by one 

 organisation. A map that is good enough for the re- 

 ception of geological lines, is capable of all the uses for 

 which a small scale ipap is ever available, while the 

 employment of men who understand something more of 

 the origin and types of topographic features than map- 

 makers usually do, must conduce to the more accurate 

 generalisation and delineation of surface features. 



It is from this point of view that the monograph of 

 topographic methods by Mr. H. Gannett ^ is likely to be 

 of considerable use, both on the staff of the Survey, for 

 whom it was primarily designed, and elsewhere. In 

 addition to giving a concise description of the chief 

 instruments employed and the methods of using them, 

 this work contains a set of logarithmic and other tables 

 for use in the field, with a short account of the method 

 of origin of the chief surface features ; this shows the 

 usual types of contour and outline special to different 

 cases, and it is so written as to give those charged with 

 the sketching of these features some rough guides for' 

 the better delineation of them. The same work gives a 

 map to show the progress of the topographic map 

 executed by the Survey, and the contributions toward 

 this work by other bodies, such as the following : The 

 survey of the Fortieth Parallel, Hayden's survey of the 

 Territories, Powell's Rocky Mountain survey, the U.S. 

 Coast and Geodetic survey, the U.S. Lake survey, the 

 General Land Office, the surveys of various States, the 

 Engineers of the US. Army, several railway, astronomical, 

 and private surveys, and the Town and County maps. 



The completed maps will be on the scales of one mile 

 and two miles to the inch, and the size of the sheets will 

 be so regulated that all sheets on the latter scale will 

 contain one-half, and those on the former, one-quarter 

 of a degree, both of latitude and longitude. 



One of the bulletins ^ contains a series of sketch maps 

 showing the systems of primary triangulation adopted 

 by this Survey and its predecessors and coadjutors. 

 Another most useful publication, also by the same writer, 

 is a set of geographical dictionaries of the several States ; 

 of these, the following are already published : Rhode 

 Island,'' Massachusetts,' Connecticut,-'^ New Jersey." Each 

 of these " is designed to aid in finding any geographic 

 feature upon the atlas sheets of the State, published by 

 the U.S. Geological Survey. It contains all the "names 

 given upon those sheets, and no other. Under each 

 name is a brief statement showing the feature it desig- 

 nates and its location, and opposite to it is the name of 

 the atlas sheet, or sheets, upon which it is to be found." 

 The heights of many important points, the length of 

 many streams, and the areas of townships are given. It 

 need hardly be said that such a task as this is one 

 which might with great advantage be taken up by the 

 Ordnance Survey at home, and the exact latitude and 

 longitude, as given on the map, might be added for the 

 purpose of precision in location. 



An article by Mr. Gannett, in one of the annual 

 reports," deduces from the contoured maps some useful 



1 Monograph xxn., "A Manual of Topographic Methods," by Henry 

 Gannett. (1893.) 



2 Bulletin 122, "Results of Primary Triangulation," by Henry Gannett. 

 (1894.) 



3 Bulletin 115, "A Geographic Dictionar>' of Rhode Island," by Henry 

 Gannett. (1894.) 



* Bulletin ii6, "A Geographic Dictionary of Massachusetts," by Henry 

 Gannett. (1894.) 



5 Bulletin 117, "A Geographic Dictionary of Connecticut," by Henry 

 Gannett. (1894.) 



6 Bulletin 118, "A Geographic Dictionary of New Jersey," by Henry 

 Gannett. (1894.) 



" Thirteenth Annual Report of the United States' Geological Survey, 

 1891-1892. (1893.) 



NO. 1376. VOL. 53] 



estimates of the height of most of the States in the 

 Union, and the average elevation of the whole country. 

 From this we gather that, while the country contains 

 200,000 square miles under lOO feet in height, there are 

 nearly 20,000 square miles above 10,000 feet. The 

 largest part of the area, half a million square miles, is 

 between 500 and 1000 feet ; the loftiest State is Colorado, 

 closely followed by Wyoming 6700, and Utah 6100 feet, 

 while the average elevation of Delaware is but 60 feet. 

 The average height of the United States is 2500 feet. 

 This article is illustrated by a beautiful orographic map 

 of the country. 



Turning now to publications of a more strictly geo- 

 logical interest, we may say a word or two about their 

 character as a whole. In addition to the maps, of which 

 the issue has now begun — these consist of three sets, 

 the annual reports, monographs, and bulletins — statis- 

 tical papers on the mineral resources of the States are 

 published annually as well. 



It is not quite easy to see what is the guiding principle 

 underlying the division of these different works. The 

 monographs are of course reserved for important and 

 original researches bearing on all branches of geology. 

 The annual report contains an account of the work 

 executed within the year, together with a collected set 

 of the more important investigations completed within 

 the same period. These do not appear to differ in any 

 marked degree from the bulletins in character, while they 

 are decidedly bulky and difficult to handle and read. 

 They are, however, profusely illustrated, and may pre- 

 sumably be taken as the more popular of the publications 

 — works intended to be used by those seeking for in- 

 forrhation on soils, water, mines, and such-like topics — and 

 as containing the researches of interest to the ordinary 

 citizen or reader. This idea seems to be borne out by 

 the amount of rather rudimentary matter given, occa- 

 sionally in somewhat high-flown language, in these 

 papers. Presumably the form of language employed is 

 well understood in the States ; but. over here, one can- 

 not help thinking that simpler language would be a more 

 fitting garment for such elementary ideas. The bulletins 

 as a rule contain simple and straightforward statemerits 

 of fact, with theory kept well in subjection ; they consist 

 of descriptions of particular areas, accounts of work in 

 the field, the laboratory or the cabinet, palaeontological 

 and correlation papers, and compact pieces of petrological 

 investigation. 



Hitherto the annual reports have been loaded with 

 a mass of details which, after once being presented to 

 Congress, need hardly have gone further, such as the 

 travelling bills of each exploring party, and other state- 

 ments of accounts. We are glad to notice that now the 

 administrative report of the director and those of the 

 heads of divisions are bound with that account in a 

 separate volume, while for several years the work on 

 irrigation has been placed within separate covers. 



We pass now to papers dealing with physiography 

 from a standpoint more or less geological, and generally 

 with the idea of providing matter of use to the general 

 public. In the first place stands the treatise by Prof. 

 Shaler on soils.^ After a preliminary description of the 

 average soil and its composition as regulated by the 

 amount of stony and organic constituents which it con- 

 tains, certain types of soils are classified as follows : — 



Cliff-talus soils. 



Glaciated soils. 



Volcanic soils. 



Soils of recently-elevated ocean-bottoms. 



The chief formative agencies are in each case de- 

 scribed, and the peculiar suitability of certain soils for 

 particular purposes, such as talus soils for vineyards, is 



1 Twelfth Annual Report of the United States' Geological Survey, 1890-91. 

 (1891.) 



