174 ANNITEHSAEY ADDRESS 



the days of Oppian ; for he has now not only explored the greatest 

 depths of the sea, but has mapped out its main features with nearly 

 as much accuracy as he has done with respect to the land. 



It will be convenient to divide the subject into separate heads, 

 viz.: — 1, Historical ; 2, Apparatus ; 3, Fauna; 4, Pood ; 5, Light; 

 6, Temperature ; 7, Depth ; 8, Inequalities of the Sea-bottom ; 

 9, Deposits ; 10, Geological ; 11, Incidental ; 12, Concluding 

 Eemarks. I hope you will not be frightened at the number of 

 these heads. Some of them you will find to be exceedingly short. 



1. Historical. 



Sir "Wyville Thomson's 'Depths of the Sea' gives an excellent 

 account of the origin and progress of deep-sea exploration up to a 

 very recent period. To this work I would refer my audience, con- 

 tenting myself with some supplemental remarks. 



In 1868 commenced the systematic examination of the sea-bed 

 at considerable depths in that part of the North Atlantic which 

 surrounds the British Isles. I then took my yacht, the * Osprey,' 

 for an excursion to Shetland, and dredged oif the most northern 

 point of our isles. The greatest depth which I attained Avas 1 70 

 fathoms, or 1020 feet, each fathom being 6 feet. This depth, 

 strictly speaking, is beyond the line of soundings, viz. 100 fathoms ; 

 and it may be a question whether the fauna of the sea-bed out- 

 side of that limit can be regarded as British, although adjacent to 

 our coasts. If it be, we ought to take the " medium filum aquae " 

 (as the lawyers in the time of Coke called it), and extend the 

 geographical limit of the British marine fauna halfway across to 

 North America ! But such boundaries are neither nationtil nor 

 rational. "We cannot lay claim to so extensive a dominion. Inter- 

 national boundaries, for the purpose of naval warfare or as defined 

 by fishery treaties, are limited to a distance of three miles, 

 irrespective of depth. Later in the same year (1868) Dr. Carpenter 

 and Professor Wyville Thomson explored, in H.M. surveying-vessel 

 ' Lightning,' the sea-bed lying between the Butt of Lewis and the 

 Faroe Isles, and reached the depth of 550 fathoms. These tentative 

 excursions showed that the sea-bed everywhere was full of Life, not 

 merely of a microscopic and uniform kind, and of a low degree of 

 organization, but of a considerable size, great variety, and a high 

 degree of organization. In the following year (1869) our Govern- 

 ment placed a better vessel at the disposal of the Royal Society ; 

 and I undertook the first scientific cruise in H.M. surveying-ship 

 ' Porcupine.' This cruise was off the western coast of Ireland, and 

 the greatest depth dredged was 1476 fathoms. The second cruise 



