" The first dredging in deep water with anything like success was obtained by the Americans; a clever Lieutenant in their Navy, invented an instrument similar to the one we now use in sounding, whereby a very small portion of the bottom could be brought up. Their dredging, however, was in comparatively shallow water, and it was reserved for an English expedition, in 1863, to bring deep-sea dredging to something like the system we are now working on. For that purpose H.M. Gun Boat "Porcupine" was fitted out for a series of soundings, dredgings, etc. i the Bay of Biscay and the home waters. A colleague of my own was among the scientific party on this occasion, and the account published by him on his return awoke the first desire for further information on the subject.
The greatest depth from which they succeeded in bringing up anything from the bottom, was 2,300 fathoms, in the Bay of Biscay. Other countries have carried on the research in a desultory sort of manner, but it was at length decided by scientific men that no country but England, and none but British seamen, could solve the problem in anything like a satisfactory manner. For this purpose the Chancellor of the Exchequer was consulted and the result was that the "Challenger" and her crew were selected for the purpose, and I am happy to say that we have thus far succeeded tolerably well. We have obtained the deepest dredging yet known in the world, viz, 3,175 fathoms, and from that depth we obtained specimens of animal life, thus proving, contrary to all our opinions that living creatures do exist in these great depths, although they are very low in the scale of animal life. I am of the opinion that the ocean is no where much deeper than 4000 fathoms and that the valley as I may call it where we obtained our deepest soundings, the other day, is of no great extent; however we shall know more about that bye & bye.
The mud that the dredge has more commonly brought up from the bottom, is of a grey colour, and, to our general surprise, on being placed under the microscope revealed nothing but the shells of what had been living creatures. This mud we found to ocntainc arbonate of lime; and the cast-off shells of these animals is causing a gradual formation of rock at the bottom of the sea, similar to the chalk cliffs onthe South of England. As regards animal life in the ocean, we find at from 200 to 400 fathoms a class of creatures of the same form and character, and the animals down to hat depth are tolerably well known to Naturalists; at 400 fathoms they are very scarce, and at 500 cease altogether, thus causing us to believe, until very recently, that below that depth no living thing existed.