242 Scientific Intelligence. 
find this little book an excellent guide. It is written from the 
modern standpoint, avoiding the use of old phraseology so likely 
to mislead the beginner, and explaining the not always simple 
ideas now accepted, clear and intelligible form; the student 
who has mastered it will be in a position to go farwatd with more 
advanced treatises without having anything to unlearn. There is 
much fresh matter introduced into the text, but in this respect 
the figures are not quite all that the book deserves. 
II. Gronoey. 
1. Glacial Erosion in Maine; by Professor GEoRGE 
Stone, of wegen College. Proc. Portland Soc. Nat. Hist. 
Nov. 21, 1881.—Professor Stone treats in this paper of the com- 
position ‘and ioe ibution and a ae of the oe in the State of Maine; 
of the ae of bite ground moraine, wher Shame in * eda 
average depth of the till is stated to be probably between 30 and 
50 feet. The rarity of sub-glacial streams is sustained for the fol- 
lowing reasons: the fact that no stratified deposits and only a 
moderate amount of glaciation have as yet been found in or be- 
cath the ground moraine; that the direction of the valleys is 
that of the glacial movement, and is sometimes transverse to 
; that there were no peaks or ridges rising above the glacier to oc 
casion the formation of crevasses ; that the capping of ice over the 
hills was so thick that the ice may have moved independently = 
the hills and valleys beneath ; and that the pressure of ice wa 
great that the lower part of the ice could har ly have been es 
jected to the strains necessary for making crevasses. 
Another reason mentioned is that no pot-holes have been found 
except within a few miles of the sea. But no pot-holes could 
have been formed from the fall of water in crevasses while the ice 
was in motion. In borings by waters to make a cylindrical pot 
hole, the tool has to work as truly about a center as in the use of 
a carpenter’s augur. A motion of even a yard a century would 
elongate it. é 
2. Glacial phenomena on any Delaware. — Professor G. F. 
WriGut, in a paper on a : of the Paleoliti-earing cae 
in Seiden staat a te ma bioag gravels rise to a 
4 
feet above aie " This fies “ roaths "sncontormably ae 
the older gravel formations.” In the Lehigh valley, t Bethle- 
hem, a few miles above its junction with the ‘Deleware valley, 
