90 The American Geologist. February, i8»;i 
stream and yet shows veiy little tillino;. The reason for this 
becomes apparent on following up the inlet for a few rods. 
The stream is found to flow out of a small lake, which serves as 
a catch basin for the sediment brought from above, and is, in 
consequence, very near the vly stage. 
The foregoing facts clearly indicate that the obliteration of 
lakes in the region described has resulted from sedimentation, 
rather than from a cutting down of the outlets. Professor Cham- 
berlin applies the latter explanation to certain swamps and peat 
bogs of Wisconsin ;* but the cases do not seem to be quite par- 
allel. 
While in some of the Adirondack lakes both causes may have 
■worked together, there is no evidence that such has been the 
case. A great objection to such a supposition is, that in no 
instance that has come under the writer's observation is there 
any evidence that the lakes ever stood for any length of time at 
a higher level. Had they done so, there would have been formed 
the same marginal meadows that are forming to-day, and some 
traces of these meadows ought, surely, to exist as terraces at the 
present time. But of such there is no indication. 
In some instances it is demonstrable that the lake never stood 
at any considerable elevation above its present level. Wilmurt 
lake is, perhaps, the best example. Some 3'ears ago the outlet 
was obstructed by a dalu two feet high, with the result that an 
entirely ncAv outlet was formed. Clearly, the lake never stood 
more than two feet above its present level, for had it done so, 
the barrier across the old outlet must have been higher than the 
artificial dam and the water would have flowed through the i)res- 
ent outlet. It ma}' ])e argued that these facts favor the idea that 
vlies are due to a cutting down of the outlet, for here, where it is 
proved that there has been no such cutting, there has been but 
small urogress made towards a vly. But sufficient reason for 
this has been already given, in stating that ver}' little water 
reaches the lake through streams. Furthermore, the efl'ect of 
deposition has been somewhat, though slightly. ol)scured by the 
recent raising of the water level. 
Hamilton CoUcgc, C/uiton, N. ¥., Ocfoher, 18!:L\ 
* Geol. of Wis., Vol. 11, p. 240. . 
