116 Prof. W. Thomson on the Depths of the Sea. 



most liberally placed the surveying gunboat ' Lightning ' at 

 their disposal, under the able and genial command of Staff 

 Commander May. On the 11th of August last, Dr. Carpenter 

 and I left Stornoway, and steamed northwards towards the 

 Faroe Islands. We had shocking weather; indeed during 

 the wliole of the cruise, which lasted nearly six weeks, we 

 could only use the dredge on nine days, and only on four in 

 deep water. We dredged a little on the Faroe banks, with 

 small results, and on the 17th of August we reached Thors- 

 haven, the capital of the Faroe Islands. We spent several 

 days exploring the fjords of that hospitable but hazy land, 

 where it seems never to be afternoon, but always grey misty 

 morning or night. On the 26th we left Thorshaven, and were 

 driven by dirty weather to the south-eastward. This was 

 perhaps fortunate ; for it forced us to examine more carefully 

 than we might otherwise have done the " cold area," to be 

 mentioned hereafter, where the bottom was of stones and coarse 

 sand, where the thermometer registered a minimum of 32° F., 

 and where the fauna consisted of a meagre sprinkling of boreal 

 and arctic forms. On the 4th of September we dredged in 

 530 fathoms, the thei-mometers registering a minimum of 

 47°' 5 F., and brought up a mass of fine, grey, slimy mud, 

 technically called " ooze," but which I shall now call "chalk- 

 mud." We traced the area having this high temperature, 

 which we may call the " gulf-stream area," southwards and 

 westwards, in a line between the plateau of the Faroes and 

 the north coast of Scotland ; and Dr. Carpenter afterwards fol- 

 lowed it as far north as lat. 61°. It is to this area and its 

 geological and biological relations that I wish specially to 

 direct your attention. 



Chalk-mud and Chalk. — During the last twenty or thirty 

 years, very great improvements have been made in sounding- 

 apparatus, so that depths can now, as a general rule, be ascer- 

 tained with a tolerable amount of precision. By two or three 

 very ingenious contrivances, cupfuls or little bucketfuls of the 

 bottom may be brought up by the sounding-line : one of these, 

 contrived by Lieut. Fitzgerald, K.N., which we used in the 

 ' Lightning,' is exceedingly clever ; I never knew it to fail. 

 The laying of the cable directed special attention to the sound- 

 ing of the North Atlantic ; and in 1857 Capt. Dayman, and in 

 1860 Sir Leopold M'Clintock accompanied by Dr.Wallich, and 

 afterwards several others, sounded the area, and brought home 

 what specimens of the bottom they could procure. The result 

 of the sounding was the definition of the great telegraph pla- 

 teau, stretching from Valentia nearly to Newfoundland, with 

 an average depth of 2000 fathoms, with greatly deeper depths 



