REVIEWS 87 
If the people of Maryland shall become convinced that, in addition 
to incidental advantages, “‘a sum in the neighborhood of three million 
dollars would be annually saved by improving the important roads of 
the state,” there will be no difficulty in getting appropriations for road 
building and repairs. The volume will exert a wide influence for the 
betterment of the roads of the country. As a piece of bookmaking it is 
exceptionally good. ‘The type is clear, the illustrations are apt and 
well-made. The Survey is to be congratulated upon presenting in 
such excellent form a volume replete with valuable information and 
suggestion. James H. SMITH. 
Maryland Weather Service, Vol. I, Baltimore. The Johns Hop- 
kins Press, 1899. 
The Maryland Weather Service is conducted under the auspices of 
the Johns Hopkins University, the Maryland Agricultural College and 
the U. S. Weather Bureau. 
In Part I, Introduction, Professor William Bullock Clark gives a brief 
history of the State Weather Service and presents “ lines of investigation 
pursued by the Service.”’ These are topography, physiography, mete- 
orology, hydrography, medical climatology, agricultural soils, forestry, 
crop conditions, flora, and fauna. He also enumerates the previous 
publications of the Service. 
Part II consists of “A General Report on the Physiography of 
Maryland, by Cleveland Abbe, Jr. Professor Abbe discusses physio- 
graphic processes in general and takes up briefly each of the physio- 
graphic provinces of the state. A study of stream development of the 
Piedmont Plateau leads to the conclusion that *‘‘The streams of the 
eastern division of the Piedmont Plateau have been superimposed from 
the formerly more extensive Coastal Plain cover.” 
Thus the explanation of McGee is confirmed by detailed field 
work—at least in the eastern part of the plateau. On page 132, Pro- 
fessor Abbe uses the phrase ‘‘ Topographic Valences of the Rocks.” 
The word ‘‘valence”’ in this connection is not defined, but imme- 
diately following the heading quoted the author speaks of the “ differ- 
-ent degrees of resistance which they [rocks] offer to weathering and 
erosion.”’ These resistances appear to be what is meant by the term 
“‘valences.”” Since valence is used in a quite different, but definite, 
PeZOs 
