268 



THE SCIENTIFIC PAPERS OF 



While at work iii the stream it was necessary to work the engine 

 in order to keep the wire vertical. The jar of the engine, however, 

 affected the mirror to such a degree that readings could only be 

 taken when the engine was stopped. 



The Tables L, II., III., IV. give the results of the several 

 lowerings. 



On August 10th the " Blake " left Hampton Roads, steaming 

 to the eastward until reaching the meridian of 74 31' W., when a 

 sounding was taken, giving a depth of 1,024 fathoms. A serial 

 was taken to a depth of 400 fathoms with two Miller-Casella 

 thermometers, which had been carefully compared with the 

 standard and found to agree at different temperatures. Imme- 

 diately after the serial with the thermometers the insulated cable 

 was lowered into the sea, and the temperature, by the galvano- 

 meter and comparison coil, recorded for the same depths as taken 

 in the first serial. Five minutes was allowed at 5 and 10 fathoms, 

 but there was no deflection of the pencil of light. The tempera- 

 ture of the surface \vas 76'5. Having lowered to 15 fathoms, at 

 end of one minute the pencil of light was 9 to the left of zero on 



