300 Bibliography. 
much more exact than (with a few exceptions) those now existing. The 
connected whole will give the higher elements, which no detached surveys 
can furnish, necessary for the more elaborate computations and results. 
points which, from their importance, or the want of knowledge in re- 
gard to them, most require it. As an illustration, may be mentioned 
the survey between Mobile and New Orleans, already in full progress, 
the results of which are important, not only locally and to the south- 
time of completion of the whole work to that of finishing each section, 
for which a few years afford approximate data, and the number of sec- 
tions under survey, which must depend upon the appropriation deemed 
by the Executive and Congress consistent with an economical adminis- 
tration of the government. The gradual extension of such a work has 
the advantage of training up agents to the due performance of its dif- 
Blake’s channel in Delaware Bay, of Blunt’s, and of the breakwater, 
or through-channel, on the ridges of Cape May, of the new south shoal, 
channel at the entrance of Mobile Bay of 203 feet. The first discov- 
eries are important to the foreign, West India, and coasting trade; an 
the latter, not only to Mobile, but to the southwest generally. Particu- 
Jars in regard to these discoveries are given in connexion with the pro- 
gress of the work in a subsequent part of this report.” 
‘The number of sheets of maps and charts now published, is sixteen 5 
and, during the remainder of the fiscal year, at least five additional ones 
will be published. Besides these, two hydrographic sketches have been 
published, and two accompany this report.” 
The sections into which the coast of the United States is divided, are 
the following : 
0, 1. From Passamaquoddy bay to Point Judith. 
No. 2. From Point Judith to Cape Henlopen. 
No, 3. From Cape Henlopen to Cape Henry. 
No. 4. From Cape Henry to Cape Fear. 
98 5. From Cape Fear to the St. Mary’s river. 
No. 8. From Mobile bay to Vermilion bay. 
No. 9. From Vermilion bay to the boundary. 
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