30 
THE VOYAGE OF H.M.S. CHALLENGER. 
a rule much larger than in the case of any other collection of deep-sea deposits, and 
they covered such a wide area in all the principal ocean basins that they must be 
regarded as fairly representative of all the deposits now forming on the floor of the 
ocean. The detailed study of these large samples has thrown so much light on the 
subject that it has been possible to interpret with great certainty the nature of the 
deposit in those regions where only a relatively small quantity of the mud, ooze, or clay 
has been obtained by other expeditions. Indeed, the number of samples of deposits that 
have been sent to us from British and foreign ships and expeditions, which we have 
examined in the manner set forth in the following tables, greatly exceed those collected 
by the Challenger ; in all, these have amounted to many thousands, and will be made 
use of in verifying all general conclusions.^ In this way we have had an opportunity of 
examining personally deposits from nearly every region of the great ocean basins, and 
from nearly all the enclosed or partially enclosed seas. An investigation, extending over 
so wide a field and occupying so long a time, necessarily involved a great amount of 
labour and patience, but led in the long run to a great familiarity with and knowledge 
of deep-.sea deposits as a whole, and their distribution in existing seas. 
c . Leading Characteristics of Deposits from different Localities. 
After a careful examination of a deep-sea deposit, following the method explained in 
the foregoing pages, it is even possible to state with a very considerable degree of 
certainty the region of the ocean in which it was formed, as well as to state approxi- 
mately the depth and distance from land at which it was procured by the sounding tube, 
dredge, or trawl. Indeed, we frequently requested our assistants to select for us a sample 
• In addition to the Challenger collectionB, the following among other collections have passed through our hands: 
— The very large and in)[>ortant collection made hy the U.S.S. “Tuscarora” throughout the basin of the great Pacific 
Oc<-an in 1873-78 ; a collection by the U.S.S. “Gettysburg” in the Atlantic in 1876 ; a large and important collection 
made by the U.S..S. “ Blake” in the Caribl>ean Sen, Gulf of Mexico, and along the eastern coasts of America, 1877-82; 
a very extensive collection from the steamships “ Silvertown,” “ International,” “ Dacia,” and “Buccaneer,” belonging to 
the India- rubWr, Gutta-|*ercha, and Telegraph Works’ Company, Silvertown, 1884-86, along the western coasts of 
Africa, around the Cojk; Verde and Canary Islands, and about the West Indies; several large collections from the ships 
of the Telegraph Construction and Maintenance Comjiany in 1879-85, along the eastern coasts of Africa, in the 
Indian Ocean, and in the Pacific Plastem Seas, and in the South and North Atlantic; many valuable and important 
collections receive<l through the Ilydrographer of the Admiralty, from Her Majesty’s surveying ships “Sylvia,” Red 
Sea, 1 ►AO; “Seine,* Indian Ocean, 1885; “ Egeria,” Indian Ocean, 1887, and South Pacific, 1887-89; “Myrmidon,” 
Coral Sea, 1887 ; “ Riimbler,” Indian and Pacific Owans, 1888-9<»; “ Valorous,” North Atlantic, 1870-75; “Investi- 
gator,” Bay of Bengal and Indian Ocean, 1H86-89; “Alert,” South Pacific, 1880; “h'lying Fish,” Indian Ocean, 1887; 
“Stork," Indian Ocean, 1888; “Triton,” P’aroe Channel and North Sea, 1882-84; “Bulldog,” North Atlantic, 1860; 
“Porcupine,” North Atlantic, 1869-70; “Lightning," North Atlantic, 1868; “Nassau,” Indian Ocean, 1876; “Argus,” 
North Atlantic, 1879; “Swallow” and “Dove,” Yellow Sea, 1865-66; “Dart,” Pacific Ocean, 1857. We have also 
receive*! specimens, or have Ijeen j>ermitte<l to examine them at different times, from the Norwegian North Atlantic 
Kxpe*liti*>n, Narcs' North Polar Expe<lition, Ross’s Antarctic Expedition, “ Talisman ” Expedition, “ Gazelle ” Expedi- 
tion, “ Ilaseler" Ex|>edition, and the U.S. Fish Commission, as well as from other sources. 
