Fic. 42.—The ‘ Hydra’ 
Sounding Machine. 
THE DEPTHS OF THE SEA. [CHAP. V. 
apparatus is so adjusted, that when 
the weight is attached and the instru- 
ment hanging ready for use, as repre- 
sented in the figure, the rod F main- 
tains a horizontal position. When the 
instrument strikes the ground, the 
tension on the bar F is relieved, the 
weight draws the rod p off the claw 
and slips off, at the same time filling 
the scoop. When hauling up, all the 
instrument falls into a nearly vertical 
line, and the scoop comes up full in 
the middle, the weight of Dp keeping 
its mouth closed up against its lid. 
The apparatus used during tlhe 
cruise of the ‘ Porcupine,’ where 
sounding was carried on to the ut- 
most attainable accuracy and at great 
depths, was a somewhat elaborate 
modification of Brooke’s sounding 
machine which had been previously 
Hl | ¥* employed by Captain Shortland in 
the voyage of H.M.S. ‘ Hydra,’ sound- 
ing across the Arabian Gulf, prepara- 
tory to laying the Indian Cable. 
This special modification, which cer- 
tainly answered remarkably well, ap- 
pears to have been due entirely to 
Mr. Gibbs, the blacksmith on board 
the vessel. We christened it the 
1 Sounding Voyage of H.M.S. ‘ Hydra,’ Captain 
P. F, Shortland, 1868. Published by order of the 
Lords Commiss. of the Admiralty. London: 1869. 
