One day in the spring of 1820, a singular occurrence took place on one of the upper tributaries of the Mississippi. The bank, some fifteen or twenty feet in height, descended quite abruptly to the stream's edge. Though both shores were lined with dense forest, this particular portion possessed only several sparse clumps of shrubbery, which seemed like a breathing-space in this sea of verdure-a gate in the magnificent bulwark with which nature girts her streams. This green area commanded a view of several miles, both up and down stream. Had a person been observing this open spot on the afteron of the day in question, he would have seen a large bowlder suddenly roll from the top of the bank to bound along down the green declivity and fall into the water with a loud splash. This in itself was thing remarkable, as such things are of frequent occurrence in the great order of things, and the tooth of time easily could have gnawed away the few crumbs of earth that held the stone in poise. Scarcely five minutes had elapsed, however, when a second bowlder rolled downward in a manner precisely similar to its predecessor, and tumbled into the water with a rush that resounded across and across from the forest on either bank.