410 Proceedings of Royal Society of Edinburgh. [sess. 
(1) The even slope of the ground from the neighbourhood of 
Bermuda to the deepest water found in Lat. 24° 50' N., no indica- 
tion being discovered of any upheaval similar to that which has 
produced the Bermudas with their adjoining shoals. 
(2) The large extent of water with depths of over 3000 fathoms. 
(3) Sounding No. 91. The undoubted evidence of a hard 
bottom or hard object in such a great depth as 2994 fathoms ; 
in this case the instrument for obtaining a specimen of the 
bottom, known as a “snapper,” was brought up dented and bent, 
with a small portion of calcareous substance enclosed in the jaws. 
(4) The formation of the coral bank on the west side of Grand 
Turk Island, as shown by the profile soundings taken off that 
island. 
(5) That the south rocks near Sand Cay in the Turk’s Island 
Passage are placed about \ mile too far south on Chart 1441. 
(6) That at its southern end the Turk’s Island Passage is 
blocked by a bank which joins the Turk’s Islands to the Caicos, 
having a comparatively narrow ridge, with between 200 and 300 
fathoms of water on it. This bank, especially on its south side, 
shows a very steep gradient into deep water. 
(7) That the cable between Bermuda and Grand Turk Island 
lies in by far the deepest water of any cable laid up to the present 
time, not only in the maximum depth attained, but also in the 
average depth of the whole section. The deepest water obtained 
on the route of the cable was 3113 fathoms, and the mean depth 
from Cable House to Cable House 27 32 fathoms. In one continu- 
ous run of twenty-four hours, during which 172 nautical miles of 
cable were paid out, the average depth was 3044 fathoms. 
A further point of interest is the comparison of the mean bottom 
temperature derived from thermometer observations with that 
obtained by electrical tests of the laid cable. Along the route 
followed by the cable over a distance of 750 miles, 102 soundings 
were taken, at a considerable number of which the bottom tem- 
perature was observed. It was possible, therefore, to determine, 
with considerable accuracy, the mean depth and mean temperature 
by thermometer. 
The following table gives the manner in which these results 
were arrived at : — 
