55 



whether these results have been attained, but whether, in a practical 

 point of view, they justify the yearly expenditure authorized by Con- 

 gress, and whether their scientific character is such as the means at 

 the disposal of the Superintendent justify us in expecting, and such 

 as is likely to meet the approbation of scientific men in our own and 

 in other countries. 



It cannot be a matter of surprise that the American Philosophical 

 Society should undertake these inquiries, since, originally consulted 

 by the government as to the propriety of instituting such a survey, 

 and the manner in which it should be conducted, they have ever 

 since, on all proper occasions^ testified their interest in its efficient 

 prosecution. 



The object of such surveys as that which is now in progress along 

 our sea-coast, is to determine with accuracy the position of every 

 conspicuous fixed point within the limits of the survey. By which 

 determination, and by the aid of the conventional marks for different 

 objects, used in topographical drawing, an accurate representation 

 may be made of the country surveyed, so that the relative position of 

 any objects, their distance apart, the character of the country be- 

 tween them, and their elevation above the level of the sea, as well 

 as the position and figure of shoals, the depth of water upon them, 

 and the nature of the bottom, the direction and force of the currents, 

 whether oceanic or tidal, the time of high and low tide, with its rise 

 and fall in our principal ports, may be easily and precisely known. 



There is scarcely a branch of physical science (chemistry alone 

 excepted) to which such a survey is not in the highest degree useful; 

 but its practical results are those of the most prominent importance. 

 Jt permits the sailor, who comes for the first time upon our coast, to 

 recognise with accuracy his position, and direct with precision his 

 vessel to its port. It warns him of the dangerous shoals which lie 

 in his path, and indicates to him the existence and strength of cur- 

 rents which may retard or assist his progress. And if he be sur- 

 prised by a tempest, which jeopards his safety, it guides him to a har- 

 bour of refuge, where he may await more favourable weather. It 

 enables the government to select with certainty the best situations, 

 both for works intended for the defence of the coast against hostile 

 invasions, and for light-houses and buoys which are to serve as guides 

 to our commerce ; and, when extended inland, it indicates the best 

 routes for internal communication, the obstacles to be overcome in its 

 establishment, and the resources which the country presents for its 

 maintenance. It may be truly said, that a government owes such 



