lost in. That piece of
agate in your hand, Mary, will show you many of the common phenomena of
breccias; but you need not knit your brows over it in that way; depend
upon it, neither you nor I shall ever know anything about the way it was
made, as long as we live.

DORA. That does not seem much to depend upon.

L. Pardon me, puss. When once we gain some real notion of the extent and
the unconquerableness of our ignorance, it is a very broad and restful
thing to depend upon: you can throw yourself upon it at ease, as on a
cloud, to feast with the gods. You do not thenceforward trouble
yourself,--nor any one else,--with theories, or the contradiction of
theories; you neither get headache nor heartburning; and you never more
waste your poor little store of strength, or allowance of time.

However, there are certain facts, about this agate-making, which I can
tell you; and then you may look at it in a pleasant wonder as long as
you like; pleasant wonder is no loss of time.

First, then, it is not broken freely by a blow; it is slowly wrung, or
ground, to pieces. You can only with extreme dimness conceive the force
exerted on mountains in transitional states of movement. You have all
read a little geology; and you know how coolly geologists talk of
mountains being raised or depressed. They talk coolly of it, because
they are accustomed to the fact; but the very universality of the fact
prevents us from ever conceiving distinctly the conditions of force
involved. You know I was living last year in Savoy; my house was on the
back of a sloping mountain which rose gradually for two miles, behind
it; and then fell at once in a great precipice towards Geneva, going
down three thousand feet in four or five cliffs, or steps. Now that
whole group of cliffs had simply been torn away by sheer strength from
the rocks below, as if the whole mass had been as soft as biscuit. Put
four or five captains' biscuits on the floor, on the top of one another;
and try to break them all in half, not by bending, but by holding one
half down, and tearing the other halves straight up;--of course you will
not be able to do it, but you will feel and comprehend the sort of force
needed. Then, fancy each captains' biscuit a bed of rock, six or seven
hundred feet thick; and the whole mass torn straight through; and one
half heaved up three thousand feet, grinding against the other as it
rose,--and you will have some idea of the making of the Mont Saleve.