HISTORICAL SKETCH OF DEEP-SEA WORK. 51 
its former activity ; and since 1866, the use of the dredge, the 
trawl, the tangles, and all the apparatus necessary for a thorough 
exploration of the fauna of the depths of the sea, has become as 
familiar to some of the navy officers attached to the Coast Sur- 
vey as the use of the sextant or the lead, and the Coast Survey 
steamers, “ Bibb, “ Hassler,” and “Blake” have acquired a 
unique reputation as deep-sea dredgers. Not only naturalists, 
but also hydrographers must be interested in Sigsbee’s volume 
on deep-sea work, published by the Coast Survey, with its de- 
tailed account of the equipment of the “Blake,” —a small 
steamer of only three hundred and fifty tons burden, which, 
under the skilful command of Lieutenant-Commander Sigsbee 
and Commander Bartlett, has done not only more rapid, but 
also far more accurate work than has been accomplished with 
the old methods and appliances by the large men-of-war usually 
detailed for similar work by European governments. The work 
of the “Bibb” and “ Hassler” is known to naturalists mainly 
from the memoirs of Pourtalés. Only a part of the results of 
the work done on the “Blake” under my direction has as yet 
been published in the Bulletins and Memoirs of the Museum of 
Comparative Zoülogy. 
But we are only at the beginning of these investigations, and 
we have much to learn as yet of the physiology of the ocean. 
We have merely skimmed the surface thus far, and have only 
traced a few thin lines with the dredge and trawl over the bot- 
tom of the oceans. 
The work of the Scandinavians has been supplemented by 
that of the Americans, and the general agreement of the results 
is most satisfactory. These results have, in their turn, been 
greatly extended by the English, and subsequently by the Amer- 
icans. Italians and French again have added to the stock of 
common knowledge which formed the basis for the great 
“ Challenger” expedition. 
