Box 23, Folder 6: Geographical and Topographical Description of Wisconsin 1855, Third Edition

25. Elevation of Places Data Table. *-Hugh Lee, Engr., South, Wis. R.R. *J. Prentice, Engineer Mil. & Watertown R.R. * Le Grand Rockwell, Central R.R.

27.

Chapter II

Lakes-Dimensions of the Great Lakes-Lake Superior-Mirage-Water Spouts-Changes of Level-Tide on the lakes Proved to exist-Land ridges or Lake beaches-Navigation of Lake Michigan-Great number of small lakes.

Wisconsin is bordered on the north by Lake Superior, so called because it is the largest body of fresh water in the world; and on the east by Lake Michigan, second only to Lake Superior in magnitude and importance. These two lakes are the upper and larger of the series of great lakes or inland seas of the North American continent. The following table shows the dimensions, and elevation above the sea of this series of lakes.

[28. Great Lakes Data Table].

Lake Superior lies in a direction nearly east and west, having an arched or curved outline. It occupies a deep valley or depression in the general plain of the country. Its coast lines extend about 1500 miles. Lake Michigan lies nearly north and south, curving towards the east at its northern extremity. Its borders are but little elevated above its surface especially at the south end. Its coast line measures about one thousand miles. Green Bay may be considered only an arm of Lake Michigan; though in any other connection it would rank as a "great lake".

29.

The navigation of the lakes, for all purposes of commerce is free and has become as important in many respects as that of the ocean. Steam boats of a large class, propellers, and sail-vessels are constantly flying on their waters carrying off the surplus products of their shores & bringing back, the manufactured articles and the product of other countries.

30.

There are a number of very interesting and important natural phenomena connected with these great lakes, some of which will be mentioned. They materially affect the climate of the adjacent country, preventing those extreme changes that are met with in other localities. On the banks of these lakes the winters are not so cold nor the summers so hot as on the high lands a few miles back. This equalization of temperature is [more] greater [near] opposite the middle than [off?] near the extremities of the lakes.

Perhaps the most remarkable of these phenomena is the mirage, which is thus described by Dr. Charles J. Jackson* "For many successive days the phenomena were presenting themselves in rapid succession along the northern shore of Lake Superior, opposite to the Isle Royale, and on the coast of the island itself, in the bays that so deeply indent its shores. At Rock harbor on several occasions I observed the little islands and points on the outskirts most perfectly represented with inverted pictures of their entire forms, hanging over their summits, the images of the spruce and other trees which crown them, being seen with beautiful distinctness directly over their terrestrial

*-Proc. of Am. Association for the Adv. of Science. Cambridge meeting (1849_ page 143.