194 THE ANTARCTIC MANUAL. 
of which material was distributed by icebergs and icefloes. For 
instance, boulders of rocks from Southern Norway are found on the 
Eastern coast of England. That they were carried there by ice is now 
universally admitted, but it is still disputed whether these rocks 
were transported across the North Sea by floating ice or by a vast 
ice-sheet which completely filled the North Sea basin. No evidence 
in support of the latter hypothesis is given by Arctic ice, but the 
great Antarctic ice barrier may conceivably be doing what some geo- 
logists assure us that the Scandinavian ice-sheet did in “the Great 
Ice Age,” and what other geologists tell us is impossible. 
Similarly, the study of Antarctic land ice may yield valuable 
assistance in explaining the origin of the old “glacial drifts.” Land 
ice was first studied in Switzerland, where the existing glaciers show 
only a limited range of action, and the study of Arctic glaciers at 
first concentrated attention upon the Swiss glacier type; for the 
differences between them were overlooked, until trained experts, 
such as Chamberlin and Salisbury from America, and von Drygalski 
from Germany, studied the Greenland glaciers. Their descriptions 
of glacial structures, not exhibited in Switzerland, have enabled a 
great advance to be made in this branch of geology. 
I. Sza Ick anp ICEBERGS. 
1. Lcebergs and Ploecbergys—The characteristic Antarctic icebergs are 
of the flat-topped variety, which in the Arctic regions have been 
called floebergs, from the belief that they were formed as floes, which 
gradually increased in thickness by the freezing of layer after layer 
to the under side of the floe. This question is still open. It can be 
tested by determining, in the case of similar Antarctic floebergs, the 
amount of salt in different layers of the berg, the presence or absence 
of marine organisms (such as diatoms) along porous layers, and the 
extent to which such marine materials can rise into the berg by 
capillary action. 
2. Layers or Bands of Clay, Stone, etc.—If these are present in a 
berg it has probably been formed from land ice. The height above 
sea-water to which such bands rise, and of the berg, should both be 
noted. 
3. Included Rocks.—The most important information to be obtained 
from icebergs is to be got by collecting specimens of the rocks and 
pebbles occurring in them. Tor rock samples, 44 in. by 3 in. by 
