[77] 



U. S. FISH COMMISSION STEAMER ALBATROSS. 



7y 



shows the differences withiu the range of temperature covered by our 

 table of corrections : " 



6 



Volume. 











1 











<D 



a 



Hubbard. 



Thorpe 

 and 







H 





Kucker. 



o 







50 



0. 99895 



0. 99902 



55 



0. 99343 



0. 99946 



60 



1.000U0 



1. 00000 



65 



1. 00067 



1. 00059 



70 



1. 00142 



1. 00127 



75 



1. 00221 



1. 00205 



80 



1. 00309 



1. 00280 



85 



1. 00402 



1. 00364 



Plate XLII shows the bow of the Albatross with the sounding ma- 

 chine and dredging boom in position. 



The Sigsbee deep-sea sounding machine a on the port side of the top- 

 gallant forecastle is shown in readiness for taking a sounding. 



The working reels containing the sounding- wire are kept in the gal- 

 vanized-ii'on tanks b b when not in use. Each tank contains sufficient 

 sperm-oil to cover the reel. 



The Tanner sounding machine c is shown in position on the port rail 

 forward of the fore rigging. 



The dredging boom h is shown in position for dredging. It is made 

 of spruce, 36 feet in length and 10 inches in diameter, with brass fit- 

 tings at the ends. The heel pivots in a heavy composition band on the 

 foremast, and the head is held in position by the topping-lift I and the 

 guys m m. 



A beam trawl d is shown ready for lowering. The wing nets e e are 

 shown in place. The bridle //is seized to the eyebolts on the forward 

 part of the runners, stopped lightly to their after ends, and lashed to 

 the end of the trawl-net. The register i is attached to the heel of the 

 boom, and is actuated by a worm wheel on the pulley shaft, thus indi- 

 cating at all times the number of fathoms of dredge rope out. 



The dredging block g is seen at the boom end; the accumulator, at 

 ft; the accumulator block, at,?'; the dredge rope, at o o ; and the hoist- 

 ing engine, at n. 



When the dredging boom is not in use it is lowered, the forward end 

 resting on the topgallant forecastle ; the topping-lift is unshackled 

 and secured abreast the foremast, aud the guys unhooked and stowed 

 away. 



DREDGING BLOCK. 



The dredging block used by the Albatross is shown in Plate XLTII, 

 Figs. 1 and 2. The shell a is made of two pieces of bar iron £-inch thick, 

 5£ inches in width at one end, 4£ at the other, and 3^ in the center. 



