plain of red-hot stones. In the same way, in the year 1698, the top of a
mountain in Quito fell in in a single night, leaving only two immense
peaks of rock behind, and pouring out great floods of mud mixed with dead
fish; for there are underground lakes among those volcanos which swarm
with little fish which never see the light.

But most volcanos as I say, are, or have been, the shape of the one which
you see here. This is Cotopaxi, in Quito, more than 19,000 feet in
height. All those sloping sides are made of cinders and ashes, braced
together, I suppose, by bars of solid lava-stone inside, which prevent
the whole from crumbling down. The upper part, you see, is white with
snow, as far down as a line which is 15,000 feet above the sea; for the
mountain is in the tropics, close to the equator, and the snow will not
lie in that hot climate any lower down. But now and then the snow melts
off and rushes down the mountain side in floods of water and of mud, and
the cindery cone of Cotopaxi stands out black and dreadful against the
clear blue sky, and then the people of that country know what is coming.
The mountain is growing so hot inside that it melts off its snowy
covering; and soon it will burst forth with smoke and steam, and red-hot
stones and earthquakes, which will shake the ground, and roars that will
be heard, it may be, hundreds of miles away.

And 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.