188

THE ASCENT OF THE MATTERHORN.

ciiai*. x.

furnished from other sources. These great rubbish-heaps areformed, one may say almost entirely, from debris which falls,or is washed down the flanks of mountains, or from cliffs bor-dering glaciers; and are composed, to a very limited extentonly, of matter that is ground, rasped, or filed off by the frictionof the ice.

If the contrary view were to be adopted, if it could be main-tained that “ glaciers, by their motion, break off masses of rock fromthe sides and bottoms of their valley courses, and crowd along everything that is movable, so as to form large accumulations of debrisin front, and along their sides,” * the conclusion could not be re-sisted, the greater the glacier, the greater should he the moraine.

This doctrine does not find much favour with those ■who havepersonal knowledge of what glaciers do at the present time. Froml)e Saussuref downwards it has been pointed out, time after time,that moraines are chiefly formed from debris coming from rocksor soil above the ice, not from the bed over which it passes. Butamongst the writings of modern speculators upon glaciers andglacier-action in bygone times, it is not uncommon to find thenotions entertained, that moraines represent the amount of excava-tion (such is the term employed) performed by glaciers, or at leastare comprised of matter which has been excavated by glaciers;that vast moraines have necessarily been produced by vastglaciers; and that a great extension of glaciers necessarily causesthe production of vast moraines. Such generalisations cannot besustained.

are separated l>y mountain ridges, nr which, at least, have islands of rock protrudingthrough the ice. The small moraiues contributed by one affluent are balanced, pro-biddy, by great ones brought by another feeder.

* Atlas of Fhysical Geography, by Augustus l'eternaiim and the ltev. T. Milner.The italics are not in the original.

t “ The stones that are found upon the upper extremities of glaciers are of thesame nature as the mountains which rise above; but, as the ice carries them downinto the valleys, they arrive lietweeu rocks of a totally different nature from theirown.”—De tsaussure, § 536.