28 6 
Dr. Davy’s observations on the 
equator, and the wind blowing from the south, the tempera- 
ture of the sea was considerably reduced. 
Where the sea is shallow, it is now a well established fact,* 
that the temperature of the water is comparatively low ; an 
important circumstance, highly deserving the attention of the 
practical navigator ; it may forewarn him of a bank in the 
darkness of night, when nothing else would indicate it, and 
put him on his guard when approaching low shores and shal- 
lows, time enough to avoid their dangers. In advancing to 
wards the Cape of Good Hope, and in doubling that pro- 
montory, and in making Ceylon, I collected some observations 
on this subject, the results, of which I shall now introduce. 
On making Table-bay, before land was to be seen, there was 
a decided fall of the temperature of the water, viz. from above 
6 o to 58, thus. 
May nth. S. lat 34 0 1". E. long. 17 0 $ 1 " at 
8 A. M. the temp, of the water was 62,5 
10 - - 62,5 
12 - 6 1,5 
2 P. M. - - 61 
5 60 
10 58 
12 - - - - 58 
2 A. M. - - - - 58,5 
4 Land in sight - 59 
7 About 20 miles from land - 58 
8 57 
* Observed by Dr. Fianklin, Mr. J. Williams, &c. See Williams’s Ther- 
mometrical Navigation. Philadelphia 1790 
