REVIEWS gl 
Then follows an account of an elaborate series of investigations of 
the flow of water through soils, sands, rocks, and other porous media. 
These are much too extended to be reviewed in detail. They furnish 
data of prime importance to studies in irrigation, water supply, and 
various other inquiries that involve the size of grain, the pore-space, and 
the various elements of resistance to percolation. The industrial as 
well as the scientific value of these determinations, with which are 
collated those of others, is obvious. 
The value of the experimental study of Professor King is greatly 
enhanced by the theoretical investigation of the motions of ground 
water by Professor Slichter. The treatment is mathematical and can 
be read only by those who are familiar with its elegant language. The 
excellent illustrations, however, translate some of the more vital parts 
into the vernacular. Those which relate to the interferences of flows 
into artesian and other wells are especially instructive. 
Ee: 
Les Lacs Francais. Par ANDRE DELEBECQUE. Ouvrage cou- 
ronné. par l’Academie des Sciences. 436 pp., 22 plates, 
and 153 figures in the text. Accompanied by an atlas of 
10 maps. Paris: 1808. 
This elaborate work is divided into ten chapters, and a brief outline 
is here given of the substance of each: 
I. Dzstribution.—Most of the lakes of France are in the moun- 
tains, the Alps, the Juras, the Vosges, and the Pyrennees ; but there are 
some in the central plateau, some along the coasts, and still others 
which do not admit of ready classification. The total number of 
lakes given is between 460 and 470, but many of them are so small 
that in our own country they would be called ponds. 
II. Depth.—The second chapter has to do with the depth of the 
lakes, and the chartings of the soundings. 
Ill. Description—The third chapter is a description of the princi- 
pal lakes, the description taking account of the depth, the area, the 
position, etc. Contour maps of the basins of more than forty lakes 
are given on the plates. Of lakes more than 25 meters deep, there 
are thirteen in the Alps, eleven in the Juras, two in the Vosges, eight 
in the central plateau, twelve in the Pyrennees, and one on the coast 
of the Mediterranean, forty-seven in all. Of lakes more than 1000 
