NARRATIVE OF THE CRUISE. 
877 
Table of the Mean Monthly Temperature at Greenwich and Sandy Point. 
Month. 
Greenwich. 
Corresponding Month. 
Sandy Point. 
J anuary 
38-3 
July 
35-4 
February 
39-3 
August 
37-4 
March 
41-6 
September 
42-4 
April 
47-1 
October 
47-3 
May 
52-9 
November 
50-7 
June 
59-0 
December 
53-2 
July 
62-2 
January 
54-8 
August 
61-4 
February 
54-4 
September 
57-2 
March 
48-0 
October 
50-2 
April 
44-1 
November 
43-6 
May 
40-4 
December 
40-3 
June 
35-4 
From this table it will be seen that the winter is very little colder than the winter at 
Greenwich, but that the summer months are considerably colder, and that the range 
of mean monthly temperature which at Greenwich is 23°'9 is at Sandy Point 19 0, 4. 
The climate of Sandy Point is, like that . of the whole southern oceanic region, therefore 
a very equable one, of uniformly low temperature, and this is doubtless due to the 
uniform temperature of the sea water, the mean range of which does not exceed 10°, 
or from 42° # 5 in winter to 52 0, 5 in summer. The mean annual temperature of Sandy 
Point is 45°‘3, and as the temperature of the deep water in the strait is 46°, there 
appears to be some connection between them, as this deep water is cut off both from 
the Atlantic and Pacific by ridges not exceeding 50 fathoms in depth. What the 
extreme depression of the bed of the channels in Magellan Strait and the inner passages 
may be, has not as yet been determined. One sounding of 565 fathoms was obtained 
in the Messier Channel, one of 400 fathoms in Sarmiento Channel, and one of 240 fathoms 
in Sea Reach ; and Sir John Narborough did not obtain bottom anywhere at 200 
fathoms in the main strait, which is sufficient to show that the lower waters here form 
an inland sea the temperature of which in all probability depends on the temperature 
of the Pacific in this latitude at the depth of the ridge separating that ocean from the 
basin, or basins, of the strait ; and this again, there is reason to think, renders the climate 
