Geology and Mineralogy. 149 
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they were made in shallow water during a progressive subsidence. 
Mr. Crosby concludes as follows: 3 
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fully accounts for the absence in these immense tracts, of all large 
The writer adds here the following objections to the theory of 
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acterizing other large islands of the ocean; (4) In the actual reefs 
and islands of the Feejee group (see the map of the Islands in the 
writer’s Corals and Coral Islands), all the conditions, from the 
first stage to that of the almost completed atoll, are well illustrated, 
one island having only a single peak of rock within the lagoon, not 
topth of the whole area, which a little more of subsidence would 
put beneath the waters and leave the lagoon wholly free. 3. D. D 
2. Glacier Motion.—In a paper by W. R. Browne on glacier 
motion, read before the Royal Society in June, 1882 (and pub- 
lished.in Nature, June 5), the author rejects all theories except that 
of Canon Moseley, which attributes it to change of temperature, 
and likens the motion to the creeping of a lead plate down a 
sloping surface. At the close of his paper the author publishes 
the following Greenland notes by Dr. Rae. 
“When in Greenland, in the autumn of 1866, I was ice-bound 
at the head of one of the fiords, and slept a couple of nights at 
an Eskimo’s house. A glacier about half a mile distant was then 
in full activity, the movement of which might, I believe, have 
been as visible to the eye as it certainly was audible to the ear. 
ly own idea is that Arctic glaciers must have a downward 
Motion more or less during the whole year, summer and winter. 
I believe the alternation of heat and éold—or, I should rather 
say, of temperature—would of itself. cause motion, especially 
uear the upper surface. . 
* 
