A rapid commences at the precise point where Fox River issues from Winnebago Lake. This rapid, down which canoes descend with half loads, extends a mile and a half, when the river assumes its usual navigable form, presenting a noble volume. Nine miles below this, a ledge of the semi-crystalline limestone rock crosses the entire channel, lifting itself five feet above the bed of the stream. Over this the Fox River throws itself by an abrupt cascade. Down this shelf of rock, the canoes, previously lightened of their burden, are lifted by the men. It was sometime after dark when we reached and encamped on the north shore, at the foot of this cascade, which bears the name of Konamik. The syllable _kon_, in this word, appears to me to be the same as _con_ in Wisconsin, and is, apparently, a derivative from a term for strong water, which has, in this case, the meaning of cascade or fall. The word _amik_, its terminal, means a beaver. We thus have the probable original meaning in beaver-water, or, by implication, beaver cascade. There is a rapid below this fall. I judged the water must sink its level, in this vicinity, about fifteen feet. On examining the character of the limestone, I discovered crystals of calcareous spar occupying small cavities. At other localities, at lower points, there were found crystals of black sulphuret of zinc, and yellow sulphuret of iron. The rock appears to be of the same age as the lead-bearing limestone of the West; it is also overlaid by the red marly clay, and I should judge it to contain deposits of sulphuret of lead. The next morning, we resumed our descent of the Fox River with difficulty. It was now the 19th of August, and the waters had reached their lowest summer stage. The entire distance of twelve miles from the Konamik to the Kákala fall may be deemed to be, at this season, a continuous rapid. Our barge was abandoned on the rapids. While the men toiled in these rapids to get down their canoes, it was found rather a privilege to walk, for it gave a more ample opportunity to examine the mineral structure and productions of the country. It was high noon when we reached the rapids of the Kákala. This is a formidable rapid, at which the river rushes with furious velocity down a rocky bed, which it seems impossible boats or canoes should ever safely descend. It demands a portage to be made, under all circumstances, the water sweeping round a curve or bow, of which the portage path is the string. This is the apparent meaning of the term, in the Indian tongue; but it is disguised by early orthography, in which the letter _l_ has taken the place of _n_, and the syllable _in_ of _au_. The term _kakina_ is the ancient French form of the Indian transitive-adjective _all_, inclusive, entirely. There is another root for the term in _kakiwa_, which is the ordinary term for a portage, or walk across a point of land, which is rendered local by the usual inflection, _o-nong_.