These so-called "kettles" were formed by the melting of large detached
blocks of ice that had been buried in moraine material thousands of
years ago when the ice-sheet that covered all this region was
receding. As the buried ice melted, of course the moraine material
above and about it fell in, forming hopper-shaped hollows, while the
grass growing on their sides and around them prevented the rain and
wind from filling them up. The one we performed in was perhaps seventy
or eighty feet wide and twenty or thirty feet deep; and without a
saddle or hold of any kind it was not easy to keep from slipping over
Jack's head in diving into it, or over his tail climbing out. This was
fine sport on the long summer Sundays when we were able to steal away
before meeting-time without being seen. We got very warm and red at
it, and oftentimes poor Jack, dripping with sweat like his riders,
seemed to have been boiled in that kettle.

In Scotland we had often been admonished to be bold, and this advice
we passed on to Jack, who had already got many a wild lesson from
Indian boys. Once, when teaching him to jump muddy streams, I made him
try the creek in our meadow at a place where it is about twelve feet
wide. He jumped bravely enough, but came down with a grand splash
hardly more than halfway over. The water was only about a foot in
depth, but the black vegetable mud half afloat was unfathomable. I
managed to wallow ashore, but poor Jack sank deeper and deeper until
only his head was visible in the black abyss, and his Indian fortitude
was desperately tried. His foundering so suddenly in the treacherous
gulf recalled the story of the Abbot of Aberbrothok's bell, which went
down with a gurgling sound while bubbles rose and burst around. I had
to go to father for help. He tied a long hemp rope brought from
Scotland around Jack's neck, and Tom and Jerry seemed to have all they
could do to pull him out. After which I got a solemn scolding for