stone having absorbed more heat than the surrounding ice—begins to sink the warmer water follows it, whilst that in the neighbouring temperature of 32° Fahr. rises to the surface and becomes in its turn re-warmed, and so on. This peculiar current often bores the holes in the ice to a depth of many feet, and is only checked by a preponderance of cold. It is the larger stones, therefore, which rise upon the ice, and the smaller ones which sink.
'SURFACE' AND 'TERMINAL' MORAINES
We walk on down the ice stream, and soon the moraines on either hand close in upon us and we find ourselves on a mere wedge of ice, at the point of which we step on to the 'surface' moraine. Here the swearing begins, and it lasts right on to the terminal face four or five miles below, for it is one continual repetition of walking on loose and tumbling rocks, up one hillock, along a ridge, jumping from
Rock to rock with many a shock,
down another hillock, now and then starting a whole avalanche of many-sided and sharp-edged stones down a treacherous slope of ice, which we take for a surface deeply covered and sound of footing.
Skate on the surface of a glacier?
'Not much!' (as the Colonials say).
AVALANCHES
Very strange notions also exist amongst the uninitiated as to the nature of avalanches. The popular
