420 E. W. Morley— Cause of the Variations 
paper, and at no very long time after their date, I think it suffi- 
cient to describe what I learn from the examination, and to 
refer to the maps themselves those who may desire to ‘form an 
independent opinion. Meanwhile I give, necessarily somewhat 
in detail, an account of the indications gained from my own 
comparison of the maps with the results of the analyses. 
The analyses here tabulated have been made with the im- 
proved apparatus alluded to in a former article in this Journal 
as intended to lessen the probable error of an analysis. -A 
comparison of the duplicate analyses made on the same sample 
will show that this intention has been carried out. 
Jan. 9, 1850, 7 A. M.—There was an area of low pressure 
over the western part of Hlinois, and of high pressure over the 
Gulf of St. Lawrence. The isobar of 30°10 inches ran from 
Montreal along the Appalachians to the Gulf of Miaticd East 
of the Appalachians, from Albany to near Knoxville, there 
were gentle winds of three or four miles an hour. ey were 
not so directed as to indicate any general current across the 
mountains. West of the mountains there were brisk winds of 
.M. 
erties in the Geecher at this pinks We was 0°20936. tt shad 
been low on the preceding day, but observations of the w 
and barometer were ic ea to determine the direution ‘of 
the great currents of the 
Jan. 10, 7 A. Mi—There was an area of high barometer hav- 
ing its center over southwestern Obio. From a little to the 
northwest of this center, winds were distinctly radiating in 
every direction with a velocity of about five miles an hour. It 
is therefore probable that the central area of high barometer 
was kept supplied by some current of air from an elevation. 
At 3 P. M. the center of radiating winds had moved so as to be 
over Lake Ontario. Cleveland was on the curve of 30°30 
inches pressure. No winds were entering this curve at the sur- 
face of the earth as far as we can Jearn from the weather map 
of this hour, while they were moving outward all around it 
with a mean velocity of several miles an hour, The high a 
sure was not materially decreased by this outflow, and this 
continuance of high pressure was not due to rise of tempera- 
