The second mate sighed. "They are immense accumulations of ice, Mivins,
that have been formed by the freezings and meltings of the snows of
hundreds of years. They cover the mountains of Norway and Switzerland,
and many other places in this world, for miles and miles in extent, and
sometimes they flow down and fill up whole valleys. I once saw one in
Norway that filled up a valley eight miles long, two miles broad, and
seven or eight' hundred feet deep; and that was only a wee bit of it,
for I was told by men who had travelled over it that it covered the
mountains of the interior, and made them a level field of ice, with a
surface like rough, hard snow, for more than twenty miles in extent."

"You don't say so, sir!" said Mivins in surprise. "And don't they
_never_ melt?"

"No, never. What they lose in summer they more than gain in winter.
Moreover, they are always in motion; but they move so slow that you may
look at them ever so closely and so long, you'll not be able to observe
the motion--just like the hour hand of a watch--but we know it by
observing the changes from year to year. There are immense glaciers here
in the Arctic Regions, and the lumps which they are constantly shedding
off into the sea are the icebergs that one sees and hears so much
about."

Mivins seemed deeply impressed with this explanation, and would probably
have continued the conversation much longer, had he not been interrupted
by the voice of his mischievous satellite, Davie Summers, who touched
his forelock and said, "Please, Mr. Mivins, shall I lay the table-cloth?
or would it be better to slump dinner with tea this afternoon?"