the question be determined by _actual observation_,
and not by _speculation_. It is of fundamental and exceeding importance to
the science.

Now, let us take a month in summer, from the observations of Mr. Bassnett,
at Ottawa. Here the climate differs somewhat from that east of the
Alleghanies; the magnetic intensity is greater, and the action more
violent and irregular. That part of the country, it should be remembered,
has a greater fall of rain in summer, for reasons we have stated, and
those periodic revolutions are more frequent.

"A brief abstract from a journal of the weather for one sidereal
period of the moon, in 1853.

"_June_ 21st. Fine clear morning (S. fresh): noon very warm 88 deg.; 4
P.M., plumous _cirri in south_; ends clear.

"22d. Hazy morning (S. very fresh) arch of cirrus in west; 2 P.M.,
black in W. N. W.; 3 P.M., overcast and rainy; 4 P.M., a heavy gust
from south; 4.30 P.M., blowing furiously (S. by W.); 5 P.M.,
tremendous squall, uprooting trees and scattering chimneys; 6 P.M.,
more moderate (W.).

"23d. Clearing up (N. W.); 8 A.M., quite clear; 11 A.M., bands of
mottled cirri pointing N. E. and S. W., ends cold (W. N. W.); the
cirri seem to rotate from left to right, or with the sun.

"24th. Fine clear, cool day, begins and ends (N. W.).

"25th. Clear morning (N. W. light); 2 P.M. (E.), calm; tufts of
tangled cirri in north, intermixed with radiating streaks, all
passing eastward; ends clear.

"26th. Hazy morning (S. E.), cloudy; noon, a heavy, windy-looking
bank in north (S. fresh), with dense cirrus fringe above, on its
upper edge; clear in S.

"27th. Clear, warm (W.); bank in north; noon bank covered all the
northern sky, and fresh breeze; 10 P.M., a few flashes to the
northward.

"28th. Uniform dense cirro-stratus (S. fresh); noon showers all
round; 2 P.M., a heavy squall of wind, with thunder and rain (S. W.
to N. W.); 8 P.M., a line of heavy cumuli in south; 8.30 P.M., a very
bright and high cumulus in S. W., protruding through a layer of dark
stratus; 8.50 P.M., the cloud bearing E. by S., with three rays of
electric light.

"29th. A stationary stratus over all (S. W. light); clear at night,
but distant lightning in S.

"30th. Stratus clouds (N. E. almost calm); 8 A.M., raining gently; 3
P.M., stratus passing off to