Knoxville daily chronicle. [volume] (Knoxville, Tenn.) 1870-1882, 1882-03-02
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 brief period.
SATISFACTORY evidence shows that
great fire must have occurred in the
out-croppings of Nova Scotia coal
district at a remote time. Fiom the
number of annual rings borne by trees
growing over the spot, it is estimated
that not less than thee 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.
BoTANIsTs in the Fontainebleau dis
trict of France have noticed considera-
BILE change in the fora of that region in
recent times. A number of species have
disappeared chiefly on account of the
severe winters. The winters of 1864,
1909, 1888 aud 1S76-S0 were 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
national misfortune), the broom heather,
ivy, holly and box. The elder, the oak,
the chestnut and the walnut have all
seriously suffered. The loss to the
Fontainebleau fora in these and other
species is replaced to some extent by the
appearance of various new species III
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 third
of this amount. From Memphis down,
distance of eight hundred and fifty
miles, the Mississippi has a 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
Benton to st. Joseph, over two thou
sand miles, only eleven and one-half
inches: and only nine and one-fourth
inches below st. Joseph to the mouth,
| q 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
Rhone 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
required to recognize touch than a
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 Dcaders. By
means of very ingenious apparatus, he
has found that the double at of recog-
nizing sound and giving a response
occupied seventy-f five thousandths of a
second, of which forty thousandths were
| required for the simple act of recogni-
ton, leaving thirty-fve thousandths for
| the act of volition One twenty fifth of
second was occupied in Judging which
of the irritants was acting upon the same
sense; but 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 a man of
| middle age, the young were somewhat
quicker; but the average of many ex-
| periments showed that the time required
for a simple thought is never less than
the fortieth of second. The mind,
| therefore, at its greatest activity. can
| perform not more than twenty-four hun
| lred simple a cts per minute-not very
great speed when it is considered how
many of these "simple acts +" must be
ombined to form any process of reason
ing or continued thought.