228 THREE CRUISES OF THE “ BLAKE.” 
Barbados. The temperature is 45° at a depth of 225 fathoms, 
at 347 fathoms off Barbados; it is 40° at 350 fathoms, while 
the same temperature is found at a depth of 713 fathoms off 
Barbados. That is, the layer of water below 150 fathoms be- 
comes gradually warmer as we go north from Pernambuco, the 
isothermal of 40° being at 350 fathoms off Pernambuco, while 
it is at 700 fathoms off Barbados and Sombrero. The isother- 
mal of 50° is at 150 fathoms off Pernambuco, at 225 fathoms 
off Barbados, and at 350 fathoms off Sombrero. 
A line of soundings southwest by south from Saline Point off 
Grenada shows the water to be as a whole colder than at simi- 
lar depths off Barbados. Off Grenada at 400 fathoms we find 
41°, at Barbados 44°; at 350 fathoms, the temperature is only 
about 1° colder off Grenada; at 300 fathoms, it is again 2° 
colder; at 150 fathoms, about 3°; and at 100 fathoms, only 1°. 
A series of bottom temperatures on the lee side of Grenada 
shows the water for depths between 100 and 400 fathoms to be 
considerably warmer than that of the corresponding depths 
standing in free communication with the Atlantic. Ata depth 
of 92 fathoms, the water on the lee side is 34° warmer than that 
of the same depth on the windward side. The same difference 
exists at 300 fathoms, and at 400 fathoms the temperature on 
the lee side is still 1° warmer. 
The bottom temperatures on the lee side of St. Vincent show. 
a similar difference. The bottom temperatures off St. Lucia on 
the lee side are slightly colder than those off St. Vincent and 
Grenada, but they are warmer than the temperatures at iden- 
tical depths in the passage between St. Lucia and St. Vincent, 
and from St. Lucia to Martinique. The lower temperature is 
probably due to the deeper passages admitting cold water on 
each side of St. Lucia, as compared with the depths at which 
water pours into the Caribbean south of Grenada, or across the 
bank of the Grenadines and through the shallower passage be- 
tween St. Vingent and Bequia. We must, however, call atten- 
tion to the remarkably cold temperature occurring between 127 
and 171 fathoms on the lee side of the Grenadines. 
On the lee side of Martinique the bottom temperatures are 
still lower, — fully as low as those of the same depths in the 
