On the Tides inthe great North American Lakes. 211 | 
the vind blow strongly up the bay and into its mouth. If a north- 
etly wind ‘prevail for som > days, as it often does, down Lake stich 
yon although i it would, for a time, heap up the waters at the hi 
en Bay (which runs nearly. parallel with the lake,) while 
Ting a sill gs eater mass towards the head of the lake, yet, 
‘sequent depression of the level at the mouth of the bay, would sc 
eal ea refluence of the accumulation at its head, even against on : 
Beet of the wind. This pecounts for the contrariety of wind 
d current during a long storm ; but it does not appear to apply to 
_ the diurnal, and even hourly, ote and floods which almost constantly 
ceed each other, whether the wind be blowing or not. A conjec- 
ture of some plausibility is suggested by i inspecting the general course 
A the winds, as they are noted down in the table. Their prevailing 
: @is up or down the bay, whose direction is about S. S. W. 
This would naturally have a tendency to roll the surface of the wa- 
ters into waves, not very unlike those of the lunar tide, excepting 
their more frequent succession. These waves, whether refluent, or 
Moving before the wind, in passing through the sinuous channel of 
the embouchure of Fox River, would be compressed into an increased 
¢levation, and may be supposed to exhibit such intervals of fluctua- 
tion, as << been so long noticed at that place. 
Tn speculating on the suinoied tides of the North American Lakes, 
ithas been natural to regard the head of Green Bay as the point 
where they would show themselves in the greatest fullness. The 
Course of planetary attraction, operating on a line from east to west, 
Would begin at the eastern part of Gloucester Bay in Lake Huron, 
and. moving over this lake to the Straits of Mackina, and thence 
across the foot of Lake Michigan and up Green Bay, would tra- 
Verse a space of from four baitdeed and fifty to five hundred miles. 
The configuration of the coasts too, through which the line passes, — 
Poe, appear to lend much extraneous aid, to give > whatever wave 
ight be formed an undue elevation ; as, after crossing Lake Huron, 
H woul dbe. ‘compressed into the seaniel, or rather triangular form of 
of the Lake which terminates at Mackina, causing a con- 
ich would naturally send it through the straits into Lake 
| with added height and impetuosity. Again, when the 
afier traversing the foot of Lake Michigan, still somewhat pre- 
‘Served In its putifinia), elevation, by a chain of islands that run almost 
J whole breadth of this transit, enters Green Bay, the same ten- 
“hey to accumulation must prevail throughout the 
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