208 Captain Edward Sabine on the temperature at 
with holes in the top and bottom, admitted free access of 
the water to a second thermometer, of similar construction 
to the first. The opportunity was very favourable for the ob- 
ject, the weather being fine, with light airs and but little 
swell : the 1230 fathoms run out in rather more than 25 mi- 
nutes, at the expiration of which time the line was fairly on 
the quarter, the ship’s drift having been bodily to leeward, 
without her having had either head or stern way ; there was 
consequently much less stray line than had been anticipated. 
The best practical judgment which Captain Clavering could 
form on the spot was, that the depth to which the thermo- 
meters had actually attained must have exceeded a thousand 
fathoms, as an allowance of the remaining 230 fathoms for 
stray line would certainly be more than ample, if no bight 
of consequence existed in the rope, which, from the appear- 
ance, and from the rapidity with which the weight drew out 
the line, might be judged the case : 230 fathoms would equal 
a drift to leeward of -|ths of a mile in 25 minutes, whereas 
that of the ship did not exceed ^ a mile an hour ; it is more 
than probable, therefore, that the depth is underrated when 
it is estimated at 1000 fathoms, or 6000 feet. The line was 
hauled in in 53 minutes, and the thermometers came up in 
good order ; the one in the cylinder to which the water had 
free access had registered 45°,5 ; the attempt to exclude the 
water from the other cylinder did not in this instance alto- 
gether succeed, in consequence of the top not having been 
screwed down sufficiently close upon the leather ; this ther- 
mometer had registered 49°,5 ; the difference of 4 0 may be 
attributed, perhaps, partly to the latter not having been so 
long in contact with the cold water as the other thermometer, 
