Knoxville daily chronicle. [volume] (Knoxville, Tenn.) 1870-1882, 1882-03-04
SCIENTIFIC MISCELLANY.

N. TIssANDIER is having constructed
in France an elongated balloon, to be
driven by small and very light electro
motor. The force i'll the first experiment
viii be supplied by an electric accuG;u-
lator, wlith will develop consi ierAble
energy for bri- f period.
SATISFACTORY evidence shows that q
great fire must have occurred in the
out-croppings of Nova Scotia ceal
district at q remote tine From the
number of annual rings borne by trees
growing over the spot. it is estimated
that not less than thu ee 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 meits.
BoTANIsTs in the Fontainebleau dis
! trict of France have noticed consldera-
bic 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 1860 We're disastrous
to vegetation, especially in places but
little protected by snow. Among the
| plants which have been frozen ont, or
| nearly SO, in Central France, are the
| maritime pine fthe 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 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,
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
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,
a 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 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
CT the brain requires an appreciable
time. Hirsch proved that less time is
required to recognize touch than 6
sound, and that it took more time to see
them than to hear, but the question Still
renamed as to what part of the time wat
, consumed IN the act of recognition. Thu.
problem was solved by Donders. B,
means of very ingenious apparatus, ht
J has found that the double st Of recog
nizing q sound and giving respons,
occupied seventy-fye thousandths of .
second, of which forty thousandths were
required for the simple act of recogni
ton, leaving thirty-fge thousandths fu
the act of volition. One twenty-fifth o
second was occupied in Judging which
Vi tile lTiIldutb WIS ACbiiiS UPON the SaIu
! sense; but slightly longer time wa
> necessary to determine the priority o
is signals sent by different senses, as thos
r of seeing and hearing. The described
results were obtained from a man O
middle age, the young were somewha
quicker; but the average of many ex
perlments showed that the time requires
" Tor simple thought is never less thai
the fortieth of a second. The mind
te therefore, at its greatest activity, cal
perform not more than twenty-four hun
bred simple acts per minute-not YER
great speed when it is considered no,
many Of these simple acts p must b.
) combined to form any process of reason
ing or continued thought.