One can get over them at an astonishing pace.

Once, as we ran on, we heard the bellow repeated, and, on coming within twenty or thirty rods of where it had seemed to be, stopped to reconnoitre.
"Bet you, he's right under that high ledge that juts out over the water there," said Kit.
"Wait a moment," whispered Wade: "we may hear him again." And, in fact, before his words were well out, the same deep, harsh sound grumbled up from the shore.
"Under that ledge, as I guessed!" exclaimed Kit.
"Sounds like an enormous bull-frog intensified," Raed muttered.
We crept down toward the brink of the ledge, Kit and Wade a little ahead.

Arriving at the crest, they peered over cautiously, and with muskets cocked.
"Here he is!" Kit whispered back of his hand.
We stole up.

There, on a little bunch of ice not yet thawed off the shore, lay the unsuspecting monster,--a great brown-black, unwieldy body.

There is no living creature to which I can easily compare it.