The evening telegraph. [volume] (Philadelphia [Pa.]) 1864-1918, 1869-09-24
POPULAR SCIENCE.


buch as those which surround the altar dnring
=! sne solemn festivals of the Greek Church appear
~ ~ INC must OF the opening 1t has been Thought
ny Quetelet, and Humboldt considered the
oplnlon probable, that this tradition had its
origin IN the successive appartion of several
Wel-marked displays of the August meteors If
inns be so, the date of the shower has slowly
snlited-as that of the November shower Is
known to have done-until now another holiday
Is associated with it, and the simple peasants of
southern Europe recognize in the falling stars
OF August the FIERY tears of good St. Lawrence
the Martyr"
The spectroscope has taught us something of
the constitution of these bodies though thew
never reach the earth's surface. Professor Her
schel, third in that line of astronomers which
has done so much for science, has employed an
August night or two in trying TO find out what
the August meteors are made of. With q spec
troscope of ingenious device, constructed bv
MIR. Browning, +. r. A. S., for the special pur-
pose of seizing the light of these swiftly moving
bodies, Professor Herschel was successful I'm
analyzng seventeen meteors. The most in
teresting of his results is his discovery that the
yellow light of the August meteors is due
TO the presence of the metal sodium in combus-
ton. This metal has very striking and char
acteristic spectrum, consisting of two bright
orange-yelow lines very close together; and this
double line was unmstakably recognized in the
spectrum of the August meteors To use the
words of the observer, their condition" (when
rendered visible to us by their combustion) sis
exactly that of a flame of gas i'm Bunsen's
burner. freely charged with the vapor of burn
newly trimmed, and largely dosed with n supply
OF moistened salt"
1t is strange to consider what becomes of all
the sodium thus dispersed throughout the upper
regions of air. There can be no doubt that in
some form or other-mixed or in combination
ii reaches the earth. The very air we breathe
must at all times contain, in however minute a
proportion, the cosmical dust thus brought to us
from out the interplanetary spaces. Nay, for
aught we know, purposes of the utmost impor-
tance in the economy of our earth, and affecting
&c
sist upon its surface, may be subserved by
this continual down-pour of meteoric
matter. We know already that the different
meteor-systems are differently constituted For
instance, the white November stars are much
less rich in sodium than the yellow August ones.
Each system, doubtless, has its special constitl-
tion, and thus the air we breathe is continually
being dosed with different forms of metallic
dust,-now one metal now another being added
with results in which, did we but know it, we
are doubtless largely interested Nor is it GER
tain that deleterious results do not occasionally
flow from an overdose of some of the elements
contained in meteors 1t might be plausibly
maintained, on evidence drawn from known
facts and dates, that occasionally mete-
pestilence with it. The sweating sick
ness" even has been associated (though, we
admit not very satisfactorily with the 33-year
returns of great displays of November shooting
stars. Without insisting on such hypothesis as
these, which scarcely rest on stronger evidence
than the notion that the destruction of Sodom
and Gomorrah was brought about by an unu-
sually heavy downfall of sodium-laden Chat is,
salt-laden) meteors we may content ourselves
by pointing out that the labors of eminent che
mists have shown that the air is actually loaded
at times with precisely such forms of metallic
dust as the theories of astronomers respecting
meteors would lead us to look for.
The Development of Cereals.
Mr.. F. F. Hallett read before the British Asso-
ment of Cereals" From continued observations
and experiments, extended over nearly twenty
years, Mr. Hallett said he had arrived at the
following conclusions-"1. Every fully-devel-
oped plant, whether of wheat, oats, or bar
ley, presents an ear superior in productive
power to any of the rest on that plant.
q. Every such plant contains one grain
than I any 9th other. 8. The best grain In given
plant is found in its best ear. 4. The superior
vigor of this grain is transmissible in different
degrees to its progeny, 8. By repeated careful
selection the superiority is accumulated. 6. The
improvement, which is at first rapid, gradually,
after o long series of years, is diminished in
amount, and eventually so far arrested that,
practically speaking limit to improvement in
the desired quality is reached. z. By still con-
tinuing to select, the improvement is maintained
and practically fixed type is the result"
The Darwinian Hypothesis.
One of the most exciting discussions in the
British Association was on DR.. Darwin's deye-
lopment theory. Three papers were read COM
batting Dr. Darwin's opinions, and in one of
them prepared by the Rev. DR.. MCann, on
''PlllOSOpllCal ODJ6cblOuS 10 DarWlnlSm or
Evolutionism" it was urged that belief in evo-
lutionism meant atheism. Professor Huxley
appeared as the defender of Darwinism, and
protested against what he termed the shallow
caricature of science and philosophy presented
by the Rev. Doctor, observing that it led one to
doubt whether the first doctor of divinity was
not CAIN and the first man of science Abel
Subsequently, Professor Huxley was elected
president for the Liverpool meeting by close
vote, Lord Stanley, to whom the post was
offered, declining to accept the position, on the
ground that he thinks the chair should be filed
by an eminent scientific man.
Hammering Iron Until IL is Red Hot.
In his lectures on 'Heat," delivered recently
at the London Institution, Mr.. G. f. Rodwell
alluded to a singular case of motion transformed
into heat, namely, the rendering of iron red hot
by repeated strokes of the hammer. Robert
Boyle, ''the father of chemistry" +" had notions OF
the transformation of mechanical movement
into heat very nearly akin to- if not quite iden-
tical with, those professed at the present day
Robert Boyle alluded to the rapid development
of heat in an iron nail by repeated blows of the
hammer after it has ceased to trave
into the wood. 1t has been asked whether
iron could be hammered colo
until it became red hot. Mr.. Rodwell informs
us that it can. Having requested blacksmith
to try the experiment, piece OF very tough iror
was hammered with a moderately heavy ham
mer it became hot, but would not scorch piece
of paper. 1t was then hammered by two men
one OF whom used sledge hammer, but with nc
better result Presently, man who was work
ing in the shop said he had often lit his forge fire
by this means, before matches were plentiful
He took q nail, such as is used for horse-shoes
and after bammerng for less than two minutes
IL with q light hammer part of the nail was
brought to bright red heat The blows were
light but frequent, and the nail was partly turned