temperature of the ocean 
and atmosphere, &c. 285 
that the maximum temperature 
is about three in the after- 
noon, and its minimum 
single example in detail. 
towards sunrise. I shall give a 
April 5th. S. 24 0 22''. 
Hour. 
W. long. 2 7 0 8". 
Temp, of the sea. 
8 A. M. 
- 
0 // 
79 V 5 
10 
- 
- 79 >5 
12 
- 
79 > 5 
2 P. M. 
- 
80 
4 
- 
- 80, 5 
6 
- 
80 
8 
- 79. 5 
10 
- 
79 
12 
- 
- 78, 5 
2 A. M. 
- 
78 
4 
- 
77.75 
6 
- 
76 
Like the atmosphere, the ocean is subject to irregularities 
of temperature. This fact is proved by the Journal in an 
ample manner. The causes which produce these irregula- 
rities may be divided, very generally, into three kinds, tem- 
pestuous weather, shoals, and currents. 
Independent of other modes of operation, and they are 
various in tempestuous weather, superficial currents appear 
to be established in the course of the prevailing winds. If 
the wind be from a cold quarter, the temperature of this cur- 
rent is comparatively low, and vice versa. This fact is mani- 
fest in the effect of the gales we experienced between the 
7th and 12th of April, during which time, being south of the 
