290 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
THE DEVELOPMENT OE DEEP-SEA SOUNDING. 
The ordinary lead and line suffieed for navigational and other purposes until near 
the middle of the present century, when the needs of deep sea investigation and 
submarine cable surveys called for improved methods. A device for detaching the 
weight was recorded in the seventeenth century, showing that attention was attracted 
in that direction at an early day. Among the earliest recorded soundings of consid- 
erable depth maybe mentioned that of Ellis, in 1749, off the west coast of Africa, where 
he reached bottom in 891 fathoms. 
In 1819 Sir John Eoss sounded in 1,000 fathoms, bringing up a satisfactory bottom 
specimen in the “deep-sea clamm’' designed by him the previous year, and described 
as follows: 
A large pair of forceps, kept apart by a bolt, and the instrument was so contrived that on the 
ludt striking the ground a heavy iron weight slip2>ed down a spindle and closed the forcejis, which 
retained within them a considerable quantity of the bottom, whether sand, mud, or small stones. 
Oflicers of the United States Eavy and Coast Survey were particularly active in 
their intelligent and systematic efforts to reach a reliable and accurate method of 
deep-sea sounding, but the results were meager so long as they retained the rojic of 
large cross-section and nondetaehable sinkers of insufficient weight. 
The causes for the many failures are made sufficiently obvious by reference to 
Professor Trowbridge’s remarks regarding the resistance of ro^iein sounding: 
The resi.stauce of the line varies, first, as the s(juare of the velocity; second, as the diameter of 
the line ; third, as the length of the line immersed. 
With the above rule in mind, and the fact that a hemi> line in sea water is only 
one-fourth its weight in air, and that its nattirally large cross-section is increased by 
saturation, it will be seen that even in moderate depths the continued action of resist- 
ance and the detleetive force of currents may approximate to the weight of the lead, 
and the line, left to sink slowly by its own weight, will continue to run out indefinitely, 
giving no warning when bottom is reached. 
The following reports of soundings made in the Atlantic Ocean and Gnlf of 
Mexico by United States and British naval oflicers serve to illustrate the primitive 
aiipliances and methods of the time and accentuate the great imiiortance of later 
experience and inventive genius. 
Lieut. M. F. Maury, United States Eavy, who was always foremost in every 
effort at advancement, adAmcated the use of a small line of great strength, made of 
the finest flax, and a largely increased Aveight of sinker. The ncAv line Aveighed less 
than 10 pounds to the nautical mile, and was measured, Avaxed, and carefully wound 
on reels of convenient size Avhen issued for use. Naval vessels were furnished Avith it 
about 1850, and some notable successes were achieved by its use, showing that it 
was a move in the right direction; yet frequent failures and discouragements Avere 
encountered. 
Lieut. William Kogers Taylor, of the U. S. S. Albany, introduced the systematic 
use of the time interval, which Avas an important improvement and continued to l>e a 
marked feature in deep sea sounding until the successful introduction of Avire, when 
its importance greatly diminished; indeed, it Avas of no service as far as the sounding 
