'228 FROM THE ST. LAWRENCE ISLANDS 



I remarked a sudden change in the colour of the 

 water, which was now again azure. The Six-ther- 

 mometer gave us the temperature, at a great depth, 

 as much warmer, and confirmed me in my opinion, 

 that we had had a less deep sea since leaving 

 Radack than is usual between the tropics. It 

 may be possible, that the bottom of the sea from 

 the Philippine islands to Radack forms a ledge. 

 The Six-thermometer gave us, to-day, at 



a depth of eighty-six fathoms - + 63° 00' 

 The 15th, it gave us, at sixty-nine 



fathoms - - - + 51 40 



The temperature of the ocean, at a depth of 

 eigthy-six fathoms, is, therefore, here, ten degrees 

 warmer than it was on the 15th, at sixty-nine fa- 

 thoms, though, according to tlie general rules, it 

 ought to be colder ; and this circumstance clearly 

 proves, that the ocean must be here much deeper 

 than in that part where we were on the 15th. 

 After an examination by Dr. Eschscholtz, the water 

 to-day was found to be a hundredth part less 

 salt. 



The Q3d. At halflpast eight o'clock in the 

 morning, we saw from deck, the island of Rota, 

 or Zarpane, in the north-west 68°, but only its 

 southern part, as the northern part consists of 

 very low land. Even the southern part was, how- 

 ever, scarcely visible, though we were distant 

 from it only nineteen miles. I steered up to Zar- 

 pane, as I wished to determine its longitude. At a 



