506 Scientific Intelligence. 
phase is wanting, and some of the lower species occur above the 
base of the Chemung formation. H. 8s. w. 4 
4. Lakes of North America; by Isrart C. Russet, pp. 1-125, 
figs. 1-9, Plates 1-23, Boston, 1895 (Ginn & Co.).—This little 
book, which its author modestly calls “a reading lesson for stu- 
dents of geography and geology,” is more than a geological trea- 
tise on the nature and significance of lakes in the surface topog- 
raphy of the country. While it lacks nothing of scientific 
precision, and the orderly arrangement of the subject-matter is all 
that a specialist could wish, there is, also, something of that 
indescribable literary flavor found in Humboldt’s “ Ansichten der 
Natur” which indicates not only a thorough knowledge and 
appreciation of the details of the topography, but an esthetic 
sense of what constitutes the beautiful in a landscape. 
As an illustration, in the midst of a description of the location 
and dimensions of Lake Tahoe, the author observes: “ On looking 
down on Lake Tahoe from the surrounding pine-covered heights, 
one beholds a vast plain of the most wonderlul blue that can be 
imagined. Near shore, where the bottom is of white sand, the 
waters have an emerald tint, but are so clear that objects far 
beneath the surface may be readily distinguished. Farther lake- 
ward, the tints change by insensible gradation until the water isa 
deep blue, unrivaled even by the color of the ocean in its deepest 
and most remote parts. On calm summer days, the sky with its 
drifting cloud banks and the rugged mountains with their bare 
and usually snow-covered summits, are mirrored in the placid 
waters with such wonderful distinctness and such accuracy of 
detail that one is at a loss to tell where the real ends and the dupli- 
cate begins, ete.” This is immediately followed by a scientific 
definition of the transparency as rendering a white disc 9°5 inches 
in diameter visible at a depth of. 108 feet, the light traversing 
twice that distance through the water to reach the eye. The 
various chapters discuss in a brief but satisfactory manner the 
origin of lake basins, the movements of lake waters and their 
geological functions, the topography of shores, and the relation 
. Of lakes to climate and to time. The facts are largely derived 
from the author’s own observations, which have been more elab- 
orately described in the various publications of the United States 
Geological Surveys. He has also drawn from the observations of 
other workers in this field, as Gilbert, Davis, Dawson, Dutton, 
King, LeConte, Upham, Warren and others. A supplementary 
note on the classification of lakes by Wm. M. Davis closes this 
very readable book. H. Ss. W. 
5. Phonolitic Rocks from Montana; by Wa ttTER Harvey 
WeEeEpD. (Communicated.)—The writer has recently returned from 
a reconnaissance trip through the Bear Paw mountains, Montana, 
where the two phorolitic rocks described in the November num- 
ber of this Journal (vol. ], p. 394, 1895) were found in place. The 
mountains present a fine example of a group of dissected vol- 
canoes. <A large part of the area is covered by extrusive basaltic 
i 
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