222 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



Cairo to Columbus, Ky. During the past summer the work 

 lias been carried on simultaneously at Cairo ami at Mem- 

 phis, and the latitude and longitude of both these places 

 have been determined. 



During the year the survey lias occupied thirteen primary 

 and fourteen secondary triangulation stations, completed one 

 hundred and fifty-nine square miles of topography and one 

 hundred and thirty-three square miles of inshore hydrogra- 

 phy, and developed two hundred and four miles of shore- 

 line. Latitudes of three and longitudes of nine places have 

 been determined. Since 1852 it has issued fifty-six charts, 

 on scales varying from 1 : 5000 to 1 : 40,000. 



This completes the account of surveys carried on under 

 the War Department. Turning now to the Coast Survey, 

 which is under the direction of the Treasury, and which has 

 by far the most complete organization for surveys of large 

 extent and great precision, we find that its regular work 

 was prosecuted during the past year with its accustomed 

 energy, although Congress had greatly curtailed the appro- 

 priations in a misdirected attempt at economy in public ex- 

 penditures. On the Atlantic coast the survey now presents 

 a continuous chain from Mount Desert to Cape Canaveral. 

 During the year progress has been made in pushing the to- 

 pography eastward in Maine and southward in Florida: off- 

 shore soundings have been obtained in both regions, and lo- 

 cal resurveys have been made of entrances where important 

 changes had occurred. The fact that so many of our har- 

 bors are barred by sands or are encroached upon by silt de- 

 mands a constant watch over the channels leading into im- 

 portant seaports, and no inconsiderable means are annually 

 devoted to this end. For New York Harbor, the entrance 

 to which is formed by narrow channels scoured by the ebb 

 current through a cordon of sands, an annual examination 

 is found necessary. Philadelphia, Baltimore, and Beaufort, 

 X. Ci,have likewise had special surveys during the past year. 

 An interesting examination of the salinity of the waters of 

 Chesapeake Bay and its estuaries has been made, with a 

 view to a study of its general regimen, and as bearing upon 

 the important question of oyster- culture. But the most 

 interesting part of the work during the past year, on the 

 Atlantic coast, is the closing of the chain of fundamental 



