REVIEWS 97 
XI. The life history of lakes—After a consideration of the various 
causes which may bring the life of a lake to an end, the history of a 
few of the principal lakes of France is sketched. The level of Lake 
Geneva has been lowered about 30 meters since the glacial time. It 
had one stationary level between the highest and the present levels, 
when the water stood ro meters higher than now. The other lakes 
especially considered are Bourget, which has also been lowered in post- 
glacial time, and d’Annecy, which was formerly 15 meters lower than 
now. ‘The rise was occasioned by alluvial deposits in the valley of the 
Fier, to which the outlet of the lake flows. These deposits have 
dammed the exit. The history of Lacs de Saint Point and Remoray 
—in the Juras—is also outlined, the interesting point being that they 
were formerly one lake, now divided into two by the growth of a 
delta completely across the narrow basin. The growth of deltas seems 
to have played a large part in the history of many of the mountain 
lakes. This is the natural course of events where torrential streams 
debouche into the standing water. Many other lakes appear to have 
had their areas greatly diminished by similar processes. Reference is 
also made to certain extinct lakes, and the criteria by which their for- 
mer existence is recognized are briefly given. 
The figures in the text of the volume are largely half tones, which 
unfortunately, cannot be said to be of more than medium grade. It 
could have been wished also that the few maps of the text which show 
features other than the topography of the lake bottoms, could have 
been clearer. On the whole they have so much ink, that it is difficult 
to find the points sought. It is always a serious problem to make a 
map clear, and at the same time get a great deal on it, and in this case 
the difficulty has not been overcome. 
Ie 1D. Se 
On the Building and Ornamental Stones of Wisconsin. By. E.R. 
eciiLion7, IID, Wilkichisom, WIS. W808, Jeo. sexi ae blz. 
Bull. No. 4. Economic Series No. 2 of the Wisconsin 
Geological and Natural History Survey. 
Dr. Buckley’s report is one of the most compendious volumes on 
the subject of building stones published in recent years. Of the three 
parts into which the subject-matter is divided the first treats of the 
demands, uses, and properties of building and ornamental stones in 
general. This is a valuable though brief discussion of the subject. 
