now for the words cone, crater, lava. If I can make you understand
those words, you will see why volcanos must be in general of the shape of
Cotopaxi.

Cone, crater, lava: those words make up the alphabet of volcano learning.
The cone is the outside of a huge chimney; the crater is the mouth of it.
The lava is the ore which is being melted in the furnace below, that it
may flow out over the surface of the old land, and make new land instead.

And where is the furnace itself? Who can tell that? Under the roots of
the mountains, under the depths of the sea; down "the path which no fowl
knoweth, and which the vulture's eye hath not seen: the lion's whelp hath
not trodden it, nor the fierce lion passed by it. There He putteth forth
His hand upon the rock; He overturneth the mountain by the roots; He
cutteth out rivers among the rocks; and His eye seeth every precious
thing"--while we, like little ants, run up and down outside the earth,
scratching, like ants, a few feet down, and calling that a deep ravine;
or peeping a few feet down into the crater of a volcano, unable to guess
what precious things may lie below--below even the fire which blazes and
roars up through the thin crust of the earth. For of the inside of this
earth we know nothing whatsoever: we only know that it is, on an average,
several times as heavy as solid rock; but how that can be, we know not.

So let us look at the chimney, and what comes out of it; for we can see
very little more.

Why is a volcano like a cone?

For the same cause for which a molehill is like a cone, though a very
rough one; and that the little heaps which the burrowing beetles make on
the moor, or which the ant-lions in France make in the sand, are all
something in the shape of a cone, with a hole like a crater in the
middle. What the beetle and the ant-lion do on a very little scale, the
steam inside the earth does on a great scale. When once it has forced a
vent into the outside air, it tears out the rocks underground, grinds
them small against each other, often into the finest dust, and blasts
them out of the hole which it has made. Some of them fall back into the
hole, and are shot out again: but most of them fall round the hole, most
of them close to it, and fewer of them farther off, till they are piled
up in a ring round it, just as the sand is piled up round a beetle's
burrow. For days, and weeks, and months this goes on; even it may be for
hundreds of years: ti