Thus he was
enabled to corroborate the fact which had been ascertained by other men
of science before him, that glacier-motion is more rapid at the top than
at the bottom, where the friction against its bed tends to hinder its
advance, and that the rate of flow increases gradually from the bottom
upwards.

While these points of interest were being established, our artist was
not less earnestly engaged in prosecuting his own peculiar work, to the
intense interest of Gillie, who, although he had seen and admired many a
picture in the London shop-windows, had never before witnessed the
actual process by which such things are created.

Wandering away on the glacier among some fantastically formed and
towering blocks or obelisks of ice, Mr Slingsby expressed to Gillie his
admiration of their picturesque shapes and delicate blue colour, in
language which his small companion did not clearly understand, but which
he highly approved of notwithstanding.

"I think this one is worth painting," cried Slingsby, pausing and
throwing himself into an observant attitude before a natural arch, from
the roof of which depended some large icicles; "it is extremely
picturesque."

"I think," said Gillie, with earnest gravity, "that yonder's one as is
more picturesker."

He had carefully watched the artist's various observant attitudes, and
now threw himself into one of these as he pointed to a sloping obelisk,
the size of an average church-steeple, which bore some resemblance to
the leaning-tower of Pisa.

"You are right, boy; that is a better mass. Come, let us go paint it."

While walking towards it, Gillie asked how such wild masses came to be
made.

"I am told by the Professor," said Slingsby, "that when the ice cracks
across, and afterwards lengthwise, the square blocks thus formed get
detached as they descend the valley, and assume these fantastic forms."

"Ah! jis so. They descends the walley, does they?"

"So it is said."

Gillie made no reply, though he said in his heart, "you won't git me to
swaller _that_, by no manner of means." His unbelief was, however,
rebuked by the leaning-tower of Pisa giving a terrible rend at that
moment, and slowly bending forward. It was an alarming as well as grand
sight, for they were pretty near to it. Some smaller blocks of ice that
lay below prevented the tower from being broken in its fall. These were
crushed to powder by it, and then, as if they formed a convenient
carriage f