316 Cotemporary Storm of the Great Lakes. 
also on the left flank of the two storms, and in the rear of the 
hurricane. But the decided inequality which thus appears in the 
wave of maximum pressure in front of these storms as compared 
with their left border, together with the early disappearance of 
any excess on this border, in the Atlantic states, after crossing 
the thirty-first parallel of latitude, will be understood better when 
we take into view another storm which this extended inquiry 
brings to our notice. I will only remark here, that the areas or 
waves of cumulated pressure which are thus found between dis- 
tant storms, as well as the gyrative character of the storms and 
their extensive barometrical depressions, appear entitled to special 
consideration in estimating, relatively, the mean barometrical con- 
ditions of different zones of the same polar hemisphere. 
Coremporary Storm or THE Great Laxes.—The inspection 
of Table IV and other observations leads me to notice another 
storm, as above mentioned, the central portions of which passed 
over the basin of the great American lakes, and the St. Lawrence, 
cotemporaneously with the progress of the first Cuba gale. 'The 
first decided barometric indication of this storm, we obtain at 
Fort Brady, at the outlet of Lake Superior, on the 2d of October ; 
from whence, advancing at the rate of about twenty-two miles 
an hour, we find its influence extending over the northern parts 
of the United States, Canada, and Nova Scotia, crossing the Gulf 
of St. Lawrence, and coinciding in part, with the phenomena of 
the first Cuba storm.* Its action, though widely extended, ap- 
pears at first to have been meideaies and it was accompanied 
with light rain, which extended over Miskiveri and a part of Ohio, 
Pennsylvania, New York, and a large portion of the New Eng- 
land states. As the storm advanced in its course, its activity ap- 
pears to have increased, and its barometric curve, blended with 
that of the first Cuba storm, becomes deeper, and, after a partial 
rising, is found to merge in the marked depression which attend- 
ed the Cuba hurricane. 
__ We may suppose that these different storms continued to pur- 
sue their several distinct courses, each crossing obliquely the path 
of another. Perhaps, too, the progress of this storm from the 
lakes might avail us in explaining more perfectly the origin of 
__* The effects of this storm on the southern borders of Lake Michigan were n0- 
mele "ate agrees 
re % 
