In a recent bulletin of the Wisconsin Geological Survey,' Goldthwait has presented the results of an interesting study of the strands of the ancient Great Lakes as they occur in eastern Wisconsin. The field-work is much more detailed and accurate than the average, and the success in reconstructing the complex series of shore-lines of Lake Algonquin, in the region studied, is largely the result of using a wye level, instead of a hand level, or aneroid barometer, in determining the heights of the ancient beaches and terraces above the present lake level as a datum plane. By far the greater part of the report is devoted to the descriptions of the old shore-lines and a review of previous work. And the conclusions on p. 42 bear only on the history of the ancient Great Lakes. In chap. iv, however, the author takes up the question of the deformation of the Great Lakes region and presents a new hypothesis as to the character of the crustal movements which have deformed the ancient shore-lines.