POLAR ICE-CAPS AND SEA LEVELS. 353 



off and thus we send an iceberg away. TJiere is 

 an ideal bay and gorge ; a great high line of 

 precipice, and ice slipping down into the water, 

 and eventually breaking off: with ice below water 

 nine times more than ice above it. There [show- 

 ing a sketch of an iceberg] is an ice precipice 

 I/O feet above, and below 1,530 feet; and here 

 is the Challenger in a snow storm just after she 

 has broken her jib-boom on the iceberg. The 

 soundings taken here are described as giving 264 

 fathoms just deep enough to float out one of 

 these huge icebergs at least they won't need to 

 crawl along the bottom of the sea, if the neigh- 

 bourhood of the shore there is anything like the 

 neighbourhood of the shore elsewhere. In some 

 places you get a depth of 250 fathoms very close 

 to the shore, but this sounding may be about 

 100 miles from the shore. In ordinary water 

 the ice will float out, when it gets into water 

 deep enough to break off. Now let us take 

 Mr. Murray's estimate of snowfall, which is 

 worked out in an elaborate manner, founded 

 upon the observations of expert German ob- 

 VOL. II. A A 



