Coast Survey of the United States. 247 
as far as they may indicate the local connections, together with 
such others as will serve to guide the philosophical inquirer. It 
would lead to but a partial estimate of the value of the coast 
survey to omit these, as well as other considerations, upon which 
there is not time to dwell. 
How well the coast survey has fulfilled the principal object of 
its institution, that is, the improvement of the navigation of our 
own shores, has been already amply illustrated. The channel 
newly determined at the entrance of New York bay, if known, 
would have permitted the entrance of D’Estaing’s fleet, and it 
appears, from a comparison of the curves of soundings, that it 
must have existed at that time. 
In Delaware Bay, there has been determined a new and straight 
ship channel, three smaller channels over the ridges of Cape May, 
and a dangerous shoal lying very near the main  ship-channel. 
At the entrance of Delaware Bay; near Capes May and Henlopen, 
three shoals have been accurately defined ; and a rock has been 
found at the entrance of New Bedford harbor, between the light- 
houses. But while navigation and its wants are the prominent 
object, information is incidentally furnished to facilitate works 
of fortification and internal improvement. Such was the case 
with regard to the fortifications projected near Sandy Hook, in 
the construction of the New York and New Haven railroad, and 
of the light-house on Tucker’s Island, and in the improvements 
on League Island in the Delaware, and the project for carrying 
the Croton water to Brooklyn across East River. 
Another point of real importance, which will reeeive the eare 
and cordial co-operation of the superintendent, is the permanent 
position and systematic classification of buoys. ‘This cannot be 
so well done until after the chart of the particular place is issued 
from the office. At present the buoys in our harbors are not well 
arranged, and hardly occupy the same place in two successive 
years. Taking the harbor of New York for an example ; there 
are a certain number of black and white buoys precisely alike. 
If the mariner falls in with one of these buoys ina fog he has 
ho means of knowing whether it marks the ‘ outer-middle,’ or 
the ‘ west-bank,’—-whether it is the buoy of the North channel, 
or of the S. W. Spit. That is, he must know his position 
by the bearings of familiar objects on the land, before the buoy 
can be a guide to him. The reader will at once perceive that if 
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