A Drainage Peculiarity. — Burr. 369 
The difference in oxidation for the two rocks is made ap- 
parent from the microscopic examination; chemical analyses; 
physical condition, megascopically andb\' the Fe203 constant 
factor, which was obtained directly from the chemical analyses 
and served as the basis for calculations in the other constit- 
uents lost and gained. 
A DRAINAGE PECULIARITY IN ANDROSCOGGIN 
COUNTY, MAINE. 
By H. T. BuEE, Cambridire, Mass. 
The drainage of the state of Maine is much impeded by the 
accumulation of glacial material in the valleys. Rivers are 
turned from their beds, and forced to struggle haltingly along 
in new and much obstructed channels. The waters are dammed 
back to form numberless lakes, which find outlet across the 
obstruction or, as sometimes happens, across a low divide to a 
valley beyond. 
A chain of such lakes empties into the Androscoggin river 
near North Leeds, Androscoggin county. The lakes occupv 
a well marked north and south valley, which is generally 
parallel to the course of the Androscoggin. From the southern- 
most of the chain, lake Androscoggin, the waters find their 
way across the divide and into the Androscoggin river. The 
cause of this diversion" is plainly to be seen in the irregular 
piles of glacial material heaped up across the valley in the 
vicinity of Leeds Centre. 
The valley of the Androscoggin river is likewise much 
clogged with drift. Thus it happens that the waters from the 
lake do not find an easy path toward the river, but are turned 
backward against the natural slope of the countrv, and finally 
join the main stream four miles north of the point where they 
leave the lake. Throughout the course of this outlet stream 
there is not a single ledge, nor a foot of rough water under 
normal conditions. So quietly does it flow that it is known 
as the Dead river. The fall between the lakes and the Andros- 
coggin river must be very slight. 
This relation has led to consequences that appear to be 
unique. The river gathers its waters from numlicrless jjranches. 
