No. 8. — Reports on the Results of Dredging, wnder the Supervision 
of ALEXANDER AGASSIZ, in the Gulf of Mexico, by the United 
States Coast Survey Steamer “Blake,” LIEUTENANT-COMMANDER 
C. D. SIGSBEE, U. S. N., Commanding. 
(Printed with the consent of C. P. PATTERSON, Superintendent U, S. C. S.) 
I. 
Description of the Sounding-Machine, Water-Bottle, and Detacher used on 
board the “Blake” by LIBuTENANT-COMMANDER C. D. Siassun, U. S. N., 
Assistant U. S. Coast Survey. 
U. 8, Coast SURVEY STEAMER ' BLAKE,” 
Hon. C. P. PATTERSON, Superintendent of the Coast Survey. 
Drar Sm, — Several years ago Sir William Thomson invented a ma- 
chine for deep-sea sounding by wire, and I quote his own words to ex- 
plain its action : — 
Captain George E. Belknap, U. S. Navy, while commanding the U. $, 
S. “Tuscarora,” during her operations in the Pacific Ocean, in 1873, was 
the first to thoroughly test the machine in general use. I had the 
honor to read the reports made by him to the Bureau of Navigation, 
Navy Department, detailing the working of the sounding apparatus. 
While it was evident that the machine for soundings by means of wire 
gave remarkable results as compared with rope soundings, its success was 
apparently due in a great degree to the intelligence, patience, and skill 
of Captain Belknap and the officers who assisted him. My study of the 
reports suggested the idea of trying to improve the machine, in order 
that it might be worked with fewer demands on the watchfulness and 
ingenuity of those having charge of it. Captain Belknap had always 
been forced to reel in the wire by hand, and one of the plans that pre- 
sented itself to me was to interpose an accumulator on the wire, between 
the reel and the sinker, which by showing the strain on tho wire at all 
times while reeling in, and by easing the sudden jerks on the wire caused 
by the motion of the ship, would allow of reeling in by steam, Under 
instructions from you I commenced, in the summer of 1874, designing 
a machine intended to carry out my views, and as the drawings advanced 
