22 
POPULAR SCIENCE REVIEW. 
in the shallow Aru sea, as well as in the shallow water by Cape 
York. Commander Chimmo’s observations, made in and around 
the Malay Archipelago, were in the main confirmed. It 
appears that there is a singular succession of marine basins 
which are cut off by barriers of varying height from com- 
munication with the ocean. From Api to Eaine Island the 
Challenger had passed through a breach in the great barrier 
reef, not far from the entrance of Torres Strait. A sea was then 
traversed for an extent of 1,400 miles, having a bottom of red 
clay, and which was included within a broken barrier consisting 
of Australia to the west, the Louisiade Archipelago, Solomon 
Islands, and a small part of New Guinea to the north, the New 
Hebrides to the east, and New Caledonia and a line of reefs 
connecting this with Australia, to the south. This, the 
66 Melanesian Sea,” had no free communication with the outer 
ocean to a greater depth than 1,300 fathoms. In the Arafura 
Sea, between Somerset Island and the Aru islands, there is 
no greater depth than 50 fathoms — the average being from 25 
to 30 fathoms ; with a bottom of greenish mud, due to the 
great rivers of New Guinea. The Banda Sea — 900 fathoms 
being the lowest limit of the barrier enclosing it — has for its 
boundaries Taliabo, Buru, and Ceram on the north, on the east 
the Aru islands, Timor and Serwatty islands on the south, and 
Celebes and the shoals of the Flores Seas on the west. The 
Molucca Passage communicates freely with the outer ocean, 
and also, by a passage of 700 fathoms depth, with the Celebes 
Sea. The Sulu Sea was the fourth of the series of marine 
basins through which the Challenger passed in succession from 
Api to Manila.* 
The ship arrived at Hong-Kong from Manila on Nov. 16. 
Here Captain Nares received a message recalling him home, 
and giving him the command of the Arctic Expedition, his 
place being filled by the appointment of Captain Thomson, who 
was at that time in command of H.M.S. Modeste , on the China 
station. After a thorough refit the Challenger again put to 
sea on Jan. 6, 1875, and passing along the west coast of 
Luzon, anchored off Manila on Jan. 11. On the 8th, 
being in the centre of the China Sea, serial temperatures at 
every 50 fathoms to 400 fathoms, and every 100 fathoms to 
1,000 fathoms were taken. At 900 fathoms the temperature 
was 36°, and this was maintained to the bottom — 2,100 
are as follows : — 1. Sent to England from New Zealand by Mr. Earl, and 
figured by Mrs. Gray. 2. Sent to France by Peron, and described by De 
Blainville. 3. Found on the surface of the Sulu Sea, on the voyage of 
H.M.S. Samarang, and described by Professor Owen, 
t “Nature,” vol. xi. p. 288. 
