362 3Ir. J. Y. Buchanan [May 29, 



work done by the ship was preparatory, getting the gear and the 

 hands into working order. Regular work commenced on February 

 13, 1872, when she left the Canary Islands to run her first line of 

 sounding and research stations across the Atlantic to the Island of 

 Sombrero in the West Indies, and fundamental discoveries were made 

 in the very first week. On the second day out, February 15, a 

 sounding in lat. 25^ 41' N., long. 20° 14' W. gave a depth of 1525 

 fathoms, but the sounding tube brought back no sample of the 

 bottom. It is remarkable as indicating the views of the time, that 

 the absence of a sample of mud was not supposed to afibrd evidence 

 that the bottom was not soft, but only that the tube had not acted. 

 It was considered inconceivable that any part of the bottom of the 

 ocean could avoid being covered with mud. 



Oceanic ideas, if I may say so, had not yet been born : thought ran 

 only on coasting lines. Notwithstanding the absence of evidence of 

 the nature of the bottom, the dredge was put over and it afforded 

 perhaps the most remarkable haul of the whole cruise. The dredge 

 came up full of masses of jet black branching coral attached to 

 black banded fragments of mineral matter resembling brown coal. 

 In every branch of coral siliceous sponges were sticking like huge 

 birds' nests. I have seen many dredgings and trawlings since, but 

 none that was so striking as this. I see it now before me as clearly 

 as I did thirty years ago on the deck of the Challenger. On that 

 day we learned two new things ; namely, that " hard ground " occurs 

 in the open ocean as well as in the tidal waters, and that peroxide 

 of manganese and allied ochres are amongst the important oceanic 

 formations. The experience of the Challenger was that manganese 

 nodules are found all over the ocean, but principally in the great depths 

 where calcareous deposits are rare or absent. On September 23, 1878, 

 while prosecuting oceanographical researches in the Firth of Clyde * 

 on the steam yacht Mallard, which I had built in that year expressly 

 for such work, I found in Loch Fyne in water of about 100 

 fathoms a rich deposit of mud which contained over 20 per cent, 

 of its bulk of manganese nodules, which, in outward appearance and 

 characteristics as well as in chemical composition, were not to be 

 distinguished from oceanic nodules. This was a very important 

 discovery. Some years later these nodules were found in other parts 

 of the Firth of Clyde. The submarine manganese nodules are a 

 distinct geological formation. Their essential constituent is an 

 ochre, that is, a higher hydrated oxide of one or more of the metals 

 of the iron group. The hydrates of the peroxides of manganese and 

 of iron are present in preponderating quantity, and they are always 

 accompanied by the homologous oxides of nickel and cobalt. The 

 association of these four metals and. the constancy of character ob- 

 served in the nodules, suggested to me as a first idea that they were 

 perhaps simply the products of the oxidation of meteorites. Further 



* ' Manganese Nodules in Loch Fyne,'i' Nature ' (1878) xviii., p. 628. 



