The Hickman courier. [volume] (Hickman, Ky.) 1859-current, 1881-12-16
SCIENTIFIC MISCELLANY.

NJ. TIssANDIER is having constructed
in France an elongated balloon, to be
driven by a small and very light electric
motor. The force in the first experiment
will be supplied by an electric accumu-
lator, which will develop considerable
energy for a brief period.
SATISFACTORY evidence shows that a
great fire must have occurred In the
out-croppings of a Nova Scotia coal
district at a remote time. F1om the
number of annual rings borne by trees
growing over the spot, ii is estimated
that not less than three hundred years
have elapsed since the FIRE was extin-
guished. But three centuries have not
cooled the ashes, and an area of some
two acres is known to be now abnor-
mally heated to such degree that
frosts never penetrate far in the severest
cold and snow. soon melts.
BoTANIsrs in the Fontainebleau dis
trict of France have noticed q considera-
bic change III the flora of that region in
recent times. A number of species have
disappeared chiefly on account of the
severe winters The winters Of 1864.
1903, 17SS and 1S76-S0 We're disastrous
TO vegetation, especially in places but
little protected by snow. Among the
plants which have been frozen out. or
nearly so, in Central France, are the
maritime pine (the loss of which was a
national mi,fortune), the broom heather,
ivy, holly and box. The elder, the oak,
the chesnut and the walnut have all
seriously suffered. The loss to the
FOntainebleau flora in these and other
species is replaced to some extent by the
appearance OF various new species in
recent times.
The average descent of larger rivers,
exclusive of cascade regions, is seldom
more than twelve inches to the mile.
and occasionally does not exceed a third
of this amount. From Memphis down,
a distance of eight hundred aud fifty
miles, the Mississippi has pitch of less
than five inches at low water, and above
the Missouri, from its source. of only
eleven and three fourths inches. The
Missouri IN its greatest length of nearly
three thousand miles, descends twenty
eight inches to the mile; but from Fort
B-nton to St. Joseph, over two thou
sand miles, only eleven and one-haf
inches: and only nine and one-fourth
inches below St. Joseph to the mouth,
n length of nearly five hundred miles.
The average pitch Of the Amazon Is a
little more than six inches to the mile
of the lower Nile, less than seven: Of
the lower Ganges, about four. The
Rhoue Is notable for a great pitch Of
eighty inches per mile from Geneva to
Lyons, and thirty-two inches below Ly-
ons TO the mouth.
The researches of scientific men have
shown that thought is not so rapid as is
usually believed, but that every action
of the brain requires an appreciable
time. Hirsch proved that less time is
al 70 roo aTrrr. rgah kIor
sound, and that it took more time to see
them than to hear, but the question still |
remained as to what part Of the time was |
consumed IN the act OF recognition. This !
problem was solved by Donders. BY /
means of very ingenious apparatus, he |
has found that the double act Of recog- |
nizing a sound and giving a response |
occupied seventy-five thousandths of a |
second, of which forty thousandths were |
required for the simple act of recogni- |
ton, leaving thirty-five thousandths for |
the act of volition. One twenty-ffth of |
n second was occupied III Judging which |
of the irritants was acting upon the same |
sense; but a slightly longer time was !
necessary to determine the priority of |
signals sent by different senses, as those |
of seeing and hearing. The described !
results were obtained from n man OF |
middle age, the young were somewhat |
quicker; but the average of many ex-
periments showed that the time required !
for simple thought is never less than
the fortieth of n second. The mind, |
therefore, at its greatest activity. can /
perform not more than twenty-four hun |
dred simple acts per minute-not a very l
great speed when it is considered how /
many of these ".simple acts " must be |
combined to form any process of reason |
ing or continued thought.