98 U. 8. Coast Survey Reports—1861 and 1862. 
‘Parts of St. Helena Sound, Port Royal Sound, Calibogue Sound, 
Tybee Roads, Wassaw Sound, St. Simon’s Sound, and the bar 
of Fernandina, were also resurveyed, and the shore lines of many — 
of the islands and rivers were traced. All these operations were 
of essential importance to the success of the national arms upon 
that coast. ¥ 
We find in these reports also the usual annual lists of devel- 
opments and discoveries made in the progress of the survey 
Some of these consist in the detection of rocks and shoals pre: 
viously unknown, lying in frequented waters, and others im — 
bringing to light new and more favorable channels by whieh 
the approaches to harbors are improved or the difficulties of — 
navigation diminished. Not less important than these are the — 
discoveries of changes produced by the shifting of sands, intro — 
ducing dangers which did not previously exist, and rendering it 
necessary to alter entirely the sailing lines which navigators have — 
been accustomed to follow. The total number of these develop: ; 
ments embraced in the general list appended to the latest report, — 
amounts to no less than two hundred and sixteen. Besides the : 
direct benefits to commerce and the national prosperity which £ 
flow naturally from the positive information gathered by the — 
coast survey, there are some indirect advantages attending 18 — 
operations, which are especially important to the interests 0 — 
science. Of these we find illustrations in the reports before Us, _— 
in the contributions embraced in the appendices, on the subjects — 
of longitude, Terrestrial Magnetism, the Solar Spo : 
expansibility of metallic bars. he papers on Longitude are by 
Prof. Peirce, and give the results of his computations from 1 
observations of the Pleiades for the recent period during which 
the moon’s path lay across that group. Some of these observ — 
tions were made both in this country and in Europe, and serve — 
to determine the errors of the tables, and thus to give additional 
value to those which were made only in this country. The 
will also serve to fix the relative longitudes of the places of 
observation, to correct the places of the stars, and inal : 
determine the moon’s semi-diameter, and “the necessity of hav 
ing regard to the A pil crn of the moon in the comp 
em.” 
solution of the pro 
Th 
e articles on Magnetism embrace the continuation of the ‘ 
Assistant Charles ott. Besides these, there is pr 
the regular biennial publication of results found at twenty-t¥? 
stations occupied st survey parties, for the 
“J 
lination, dip and intensity. 
