of Edinburgh, Session 1881-82. 
649 
We have named the ridge “ Wyville Thomson Ridge” in honour 
of the late Sir Wyville Thomson. 
Its position is shown on the map by the contour lines of 300 
fathoms. The exact height and form of the ridge, however, has still 
to be determined by a series of soundings in cross sections, and this 
work we hope to undertake during the present season.* 
If we trust to the indications given by the serial temperature 
soundings, we should say that the depth over the ridge cannot much 
exceed 200 fathoms. 
The discovery of this ridge is an important fact in Physical 
Geography, and is in itself a sufficient justification, if justification 
were needed, for a thorough reinvestigation of so highly interesting 
a region in such close proximity to our own shores. The dis- 
covery confirms strongly the correctness of the theory that sub- 
marine ridges exist in all cases in the ocean, between adjoining 
areas, the bottom temperatures of which differ materially at equal 
depths. 
What is the Geological nature of the Wyville Thomson Ridge 2 — Is 
it an outcrop of ancient rocks like those of the north of Scotland % 
Is it of volcanic origin % Is it the remains of an ancient moraine % 
We have no very definite information on this point, but such as we 
have seems to indicate that the last supposition is the correct one. 
The two dredgings on the ridge — the one about mid-channel and the 
other at the north end of the ridge — both gave large stones,— 
Cambrian sandstone, diorite, micaceous sandstone, mica schist, 
gneissic rock, limestone, amphibolite, chloritic rock. These were all 
more or less rounded, and in some cases glacial markings could be 
detected. The assemblage of stones altogether resembled very much 
what we would expect to find in a moraine heap, such as would be 
formed from rocks found in the north of Scotland, .rather than from 
those found in the Faroe Islands, which are volcanic. 
We know of no agent at work at present in this region which could 
transport these stones to their present position. When lying on the 
bottom many of the stones projected above the deposit; and their 
* On the recommendation of the President and Council of the Eoyal Society 
of London, and the Hydrographer, the Lords Commissioners of the Admiralty 
have detached H.M. surveying vessel “Triton” for two months during this 
summer ( 1882 ), to complete the work commenced in the “ Knight Errant.” 
