* 
40 C. G. Rockwood—Notices of recent Harthquakes. 
seems equally probable, even without collateral evidence, which 
we have, that the glacier moved in the same direction along 
across the euroboreally disposed barriers, down slopes whose 
general descent is euronotal, or across the euronotally-disposed 
barriers, down slopes whose general descent is euroboreal, 
Not to pursue the discussion further, we think the facts will 
justify the enunciation of the following general proposition: 
The actual topogrophical and hydrographical axes of Michigan 
are the resultant of two forces—a glacial, acting from the northeast, 
and a stratigraphical, acting along the lines of strike. 
s a corollary, we shall find that where the rocky formations 
are most consolidated, the resultant lies nearest to the strati- 
graphical force; and where the rocky formations are little con- 
solidated, the resultant approximates the line of the glacial 
oree, 
been-determined by post-glacial erosions, and river-courses, like 
the St. Clair and Detroit, marked out across lacustrine or other 
post-glacial deposits which have concealed the surface features 
ue to geological structure or glacial erosion, 
Syracuse University, May 26, 1873. 
Art. IX.—WNotices of recent Earthquakes ; by Prof. C. G. Rocx- 
x woop, Jr., Bowdoin College. 
. They were felt from Eugene City, Oregon, north into 
British Columbia, and on both sides of the mountains, i. e. 
* Michigan Geolological Report, 1861, p. 128. 
