TRANSACTIONS OF SECTION E. 71[> 



during the century: it is designed to give such au account of these institutions, of 

 their history and of their methods and results, as will bring out the relations 

 among the institutions and introduce a somewhat more detailed account of the 

 wiirk of particular surveys and bureaus presented Ijy other American repre- 

 sentatives. 



-. A II rief Account of (he Ceor/rapJiic Work of the United States Coast and 

 Geodetic Survey. By T. C. \lv.^JiETinK\A., foiinerly Superintendent of 

 the Survey. 



This paper begins with a summarj^ slcetch of tlie history of the United States 

 Coast and Geodetic Survey since its creation in 1S07, and proceeds to describe the 

 development and improvement of methods, as -well as the extension of the work 

 from the bays and harbours of the middle Atlantic slope to all portions of the 

 American coast. The methods, purposes, and results of the transcontinental 

 triaugulation are set forth, together with leading features of the work in the 

 measurement of gravity for the purpose of determining the figure of the earth and 

 controlling the detailed surveys. The precise determination of latitudes and 

 longitudes is also described, and the methods and extent of mapping are indicated. 

 Reference is made also to the preparation of the coast pilots and to the deter- 

 mination of terrestrial magnetism, &c. 



3. The Hydrography of the United States. By F. H. Newell, Chief of 

 the Division of Hydrography oi the United States Geographical Survey. 



This is an account of the development of hydrographic surveys in the United 

 States up to the present date. All of those surveys are relatively recent, and it is 

 shown that the period of exploratory work has passed — already the locations of 

 .streams and lakes are known. The second stage of progress in which the A'olume 

 und fluctuations of the water are ascertained has been entered upon ; the study of 

 the applications of these determinations to welfare is just beginning. The field of 

 investigation is first outlined, and the purposes of the investigation are set forth ; 

 theii the investigations are described in some detail for the purpose of indicating- 

 methods and suggesting applications : and the paper closes with a summary state- 

 ment of results. 



4. The Coastal Plain of Maim. By Professor William Moekis Davis. 



Southern Maine is bordered by a narrow and irregular coastal plain, dissected 

 by numerous small valleys. It is ordinarily the case that coastal plains are limited 

 by sub-parallel lines marking the former and present shore line of the region, as 

 may be seen in the typical example that skirts the eastern margin of the Deccan 

 in India. But the coastal plain of Maine has a most irregular inner and outer 

 boundary, and its surface is interrupted here and there hj ridges and hills of 

 rugged rocky surface, similar to that of the oldland further inland. The inner 

 boimdary or former shore line is irregular, because it marks the edge of a parti)' 

 submerged hilly region at the time the clayey strata of the plain were accumu- 

 lating. The outer boundary is irregular, because the period of submergence and 

 deposit did not endure long enough to produce a smooth sea-bottom ; hence, when 

 the plain was revealed by elevation, the new shore line was little less ragged than 

 the old shore line, and time enough has not yet passed for its simplification, even 

 l)y the strong Atlantic waves. The streams and rivers, extended from the oldland 

 across the plain, have incised valleys along their consequent courses. Thus the 

 siU'face of the plain is to-day of moderate inequality of form. At many points the 

 streams have cut down their channels upon buried ledges, and thus falls are 

 developed. In coastal plains of simpler form such falls occur only near the inner 

 border of the phain ; here they may occur close to the outer border, and this is no 



