tot onoAt vooPs Ill 
The fish is therefore unable to go down to 
the bottom again, but rises helplessly, and 
more and more rapidly, until it reaches the 
surface, usually dead, with its body greatly 
distended, and sometimes even split open. 
VERY COLD 
The deep sea is a very cold haunt, for the 
sun’s heat is practically lost at about 150 
fathoms; and there is a continual sinking 
down of cold water, rich in oxygen, from the 
Poles, especially from the South. Throughout 
the year there is little variation in the abyssal 
temperature, which remains at about 28°-34° 
Fahrenheit, a little on each side of the freez- 
ing-point of fresh water. Eternal winter 
reigns. ‘There are cleverly made thermome- 
ters for taking the temperature of the abysses; 
thus, after the well-protected thermometer 
has been down for a while, a metal “mes- 
senger” is sent spinning down the wire, which 
hits a spring and turns the thermometer up- 
side down, so that it cannot change on the way 
up. Ina similar way water-bottles that collect 
samples of the water at various depths can 
be automatically closed at any point. 
