168 W. P. Trowbridge on Deep Sea Soundings. 
7sth of an inch in diameter. These latter results were obtained 
from the observations of Lieutenant Commanding Joseph Day- 
man, who sounded across the Atlantic along the line proposed 
for the ocean telegraph, in the summer of 1857. The deductions 
from Lieutenant Dayman’s experiments confirm those obtained 
from the observations of Lieutenants Lee and Berr 
of about 2000 fathoms the velocity is hardly two feet per sec- 
ond; 8d, that at this point nearly the whole resistance is due to 
the line, the resistance to the sinker being only a fraction of a 
ction. 
_In table IV the same result is obtained with a larger line, the 
Sa) Se line, the moving weights being 126 and 96 pounds. _ 
‘e may therefore conclude that for the same length of line 
moving with different velocities the resistances are proportio 
to the squares of the velocities. 
To ascertain the law of variation with the length, I have taken 
those points in the two cases at which the velocities are the same, 
Corresponding of course to different depths or lengths. The re- 
_ sults are given in table III, where the ratios of the lengths are 
_ compared with the ratios of the resistances, From this table it 
‘appears that the resistances are directly proportional to the 
‘That is, if 2 represent the resistance upon a given length, 
; h a velocity V; the resistance upon double the 
appear to hold true for all depths, for if we take 
lengths correspondi the same 
pondines to 
a 
a eran 
