344 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
THE DEVELOPMENT OF DEEP-SEA EXPLOKATION. 
The systematic exploration of the deep sea has been eonliued almost entirely to 
the second half of the nineteenth century, and may be said to have commenced Avith 
the general introdnction of steam, which not oidy furnished power to hoist the dredge, 
but brought the A^essel under sufficient control for successfully working the apparatus. 
A sailing A^essel, even under favorable conditions, Avas not Avell adapted for the Avork 
of deep-sea cxidoration ; there Avere no means of preventing her drifting to leeAvard 
when hove to, and this made the preliminary operation of sounding, even in a few 
hundred fathoms, a diflicnlt matter Avith the old-fashioned deep-sea lead line, AA-hich 
Avas sloAV to sink, and Avith its great and uncertain angle left the actual depth requisite 
to the successful operation of the dredge still in doubt. Henqi dredge rope, used 
prior to 1877, Avas another serious obstacle to the extension of deep-sea exploration — 
its size increasing Avith the depth, and the Aveights requii’cd to sink it to the bottom, 
in spite of the rapid drift of the vessel, increasing the load Ijeyojid the lifting capacity 
of appliances then found on shipboard. 
Midler, one of the tirst recorded iiwestigators, used a small dredge on the Danish 
and N'orwegian coasts as early as 1779, but 30 fathoms aa^us his greatest depth. Sir 
John Iloss brought up specimens of animal life about 1819 Avith his “deep-sea clamm” 
from ],0()0 fathoms, Avhich caused much comment, as 300 fathoms had been generally 
considered the limit beyond Avhich no life existed in the Avaters of the sea. 
ITof. Louis Agassiz commenced his explorations of the coast waters of the United 
States in 1847, and Verrill and Stinq)Son folloAAmd in 1859, all confined to depths 
within 50 fathoms. In 18G0 Dr. Wallich reported starfish from 1,200 fathoms, brought 
up on the sounding line. 
From 1896 to 1809 Fourtales made an extended series of dredgings on board the 
Coast Smwey steamer Coriri)i, Acting Master Robert Platt, U. S. N. He made a 
successful haul in 800 fathoms between Key West and Havana, and reached the 
unprecedented deiith of 1,125 fathoms in the Yucatan Channel. 
In 1808 Wyville Thomson and Dr. Carpenter, on board the Lu/hfning, dredged in 
000 fathoms between Scotland anil the Faroe Islands, Avhere they found an abundance 
of marine life, and, extending their explorations to 1809-70, on board the Poyeiipine, 
they made a successful haul of the dredge in 2,435 fathoms, Avhich was a great triumph, 
considering the crude appliances of the day. 
The United States Fish Commission commenced dredging operations in 1871, using 
hemp rope, as their jiredecessors had done, and, Avorking from small A^essels having 
limited si)ace, Avith inq)erlect appliances of a, temporary nature, they Avere I'estricted to 
depths not exceeding 150 fathoms. 
H. B. M. S. Challenger, a spur-decked sloop of Avar of 2,000 tons and 1,200 horse, 
power, an unusually commodious vessel, Avas fitted out for deep-sea exploration and 
sailed on her memorable scientific cruise around the Avorld in December, 1872. Her 
equipment included large quantities of hemp dredge rope Avhich, Avhen Avet, Avas lieaA^y 
and bulky, requiring much labor to itroperly attend and care for it, yet her large and 
