At the rapids of Black River, which enters opposite our encampment, a saw-mill, we were informed, had been erected by an inhabitant of Prairie du Chien. Thus the empire of the arts has begun to make its way into these regions, and proclaims the advance of a heavy civilization into a valley which has heretofore only resounded to the savage war-whoop. Or, if a higher grade of society and arts has ever before existed in it, as some of our tumuli and antiquities would lead us to infer, the light of history has failed to reach us on the subject.[104] [104] _American Antiquities._ As the tumuli and earthworks of the Mississippi Valley are more closely scrutinized, they do not appear to denote a higher degree of civilization than may be assigned to the ancestors of the present races of Indians, prior to the epoch of the introduction of European arts into America. Certainly there is nothing in our earthworks and mounds, to compare with the Toltec and Aztec type of arts at the opening of the 16th century; while the possession by our tribes of the zea maize, a tropical plant, and other facts indicative of a southern migration, appear to denote a residence in warmer latitudes. The distribution of the Mexican teocalli and pyramid is also plainly traceable from the south. Neither the platform nor the solid conical mound has been traced higher north than Prairie du Chien; nor have the earthworks (adopting Carver's notices) reached higher than Lake Pepin. There are no mounds or earthworks at the sources of the Mississippi nor in all British America to the shores of the Arctic Seas. We cannot bring arts or civilization from that quarter. At the spot of our encampment, as soon as the shades of night closed in, we were visited by hordes of ephemera. The candles lighted in our tents became the points of attraction for these evanescent creations. They soon, however, began to feel the influence of the sinking of the thermometer, and the air was imperceptibly cleared of them in an hour or two. By the hour of three o'clock the next morning (5th) the expedition was again in motion descending the river. It halted for breakfast at Painted Rock, on the west shore. While this matter was being accomplished, I found an abundant locality of unios in a curve of the shore which produced an eddy. Fine specimens of U. purpureus, elongatus, and orbiculatus were obtained. With the increased spirit and animation which the whole party felt on the prospect of our arrival at Prairie du Chien, we proceeded unremittingly on our descent, and reached that place at six o'clock in the evening.