Personal and Scientific Hews. 127 
treated to the northeast ponded the water, creating lakes. The overflow 
trenched the barriers and connected the lakes by short streams. The 
effect of the draining and filling has been to obliterate the lakes and to 
accentuate the character of the stream. Near its mouth the river has 
built up alluvial flats through which it meanders, resembling in this 
part, of its course the older streams of the Coastal plain of the United 
States. This resemblance is still more enhanced by the presence of a 
crescent shaped cut-off, characteristic for the old age of rivers. Farther 
up the stream the lakes, whose life history is inseparably connected 
with that of the river, become more numerous and show various stages 
of development. The Michigan lumbermen have built numerous dams 
along the river, usually at the outlets of the lakes, and by replacing the 
barriers trenched by the river have rejuvenated some of the lakes. Oth- 
ers which had been drained have been regenerated, and thus the condi- 
tions existing during or shortly after the close of the Glacial epoch have 
been to some extent restored. 
The source of the river is in the copious springs which are fed by the 
water of Bone lake, whose water level is about 30 feet above the springs 
and only 125 yards distant. A valley leads from these springs up to the 
lake, and at the shore is about 3 feet above the water. The outlet of 
the lake is the west branch of the Fence river, three-fourths of a mile 
distant from, and to the east of, the head of the Deer river valley. A 
dam at the lake outlet raised the water sufficiently to cause it to flow 
through the Deer river valley, adding temporarily to the Deer river sys- 
tem a stream 7 miles long, including in its course three large lakes. 
This necessitated, of course, a second dam at the head of the Deer river. 
No data are at hand which show whether or not the system thus artifi- 
cially added to the Deer river originally belonged to it. 
New York Academy of Science. 
At the meeting of the section of geology and mineralogy 
held January 20th, Professor J. J. Stevenson in the chair, the 
following papers were presented. 
The first by E. O. Hovey described the new and remarkably 
fine specimens of rare minerals recently discovered by Mr. 
Niven in the upper part of New York City. A double termi- 
nated tourmaline 94 inches long by 4^ inches in diameter was 
shown, and also unusually large samples of xenotime and 
monazite. The largest xenotime was f inches in diameter, the 
monazite was about £ inches on the long edge. Fuller 
crystallographical details appear in the Bulletin of the Ameri- 
can Museum of Natural History of recent date. 
The second paper was by J. F. Kemp and T. G. White and 
brought out the result of further exploration in the Adiron- 
dacks, the Lake Champlain valley and the Green mountains as 
regards the distribution of the trap dikes, well known from 
that region. One was cited on mount Mclntyre about 4.0C0 
feet above tide, and others from various interior points in the 
Adirondacks. Microscopic study shows that they arc in 
instances both camptonites and fourchftes. This modifies 
the previous experience of Kemp and Marsters, who had 
found onty diabase dikes in the Archean rocks. A greal 
number of dikes were mentioned from the shores of Willsboro 
bay, on the New York side; one dike of camptonite from the 
