No. 8. — Ueports on tJie Results of Dredging, under the Supervision 

 of Alexander Agassiz, in the Grvilf of Mexico, hy tlie United 

 States Coast Survey Steamer "Blake" LlEUTENANT-COMMANDER 

 C. D. SiGSBEE, U. S. K, Commanding, 



(Printed with the consent of C. P. Patterson, Superintendent u. S. C. S.) 



Description of the Sounding-Machine, Water-Bottle, and Detacher used on, 

 hoard the "Blahe" by Lieutenant-Commander C. D. Sigsbee, U. S. N., 

 Assistant U. S. Coast Survey. 



U. S. Coast Survey Steamer " Blake." 

 Hon. C. p. Patterson, Superintendent of the Coast Survey. 



Dear Sir, — 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. 

 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 dne 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 the 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 



