Charlotte home and Democrat., 1882-01-13

manner in which the tail of the great
comet seen in 1853 was bent at its ex-
tremlty favors this idea. Il looked as if
the motion of the comet was so rapid that
the extremity of its tail, which, In the
whirl around the sun to keep its position,
must move the fastest, was not able to
accomplish its task, and was being left be-
hind. Hence, if minute portions and
vapors forming the extremity of the tail
could not keep up, they might have been
left to float for time in space. Such frag-
ments might therefore be picked up by
one of the planets.
Is it not worth while, then, for our as
tronomers to ascertain whether any one of
the comets Of the past year moved in such
direction that part of its tail has been
caught by our atmosphere Denning's
comet, discovered Oct 8 in England ,passed
within three and half million miles of
the earth's orbit in its ascending node,
and is supposed to have made seven rev.
olutions within the last sixty years. 1t
was stated in the newspapers that the
large comet visible during the summer
approached within sixty-seven million
miles of the sun, and was, therefore, with
it's long tail, many million miles inside the
e3rth'S orbit.
The immense rapidity with which some
of the comets move should be kept in
mind. Sir Isaac Newton estimated the
speed of one of them when it was nearest
the sun as equal to 200 miles per second,
which is nearly thousand times as great
as the rapidity with which sound is trans
mitted through the atmosphere. Of
couree, with such speed as this it's whirl
around the sun, requiring as it would still
greater rapidity OF movement in it's tail,
might we'll be supposed to leave portions
of the matter of the latter to float in space
and be taken up by the earth in its revolu-
tions.
Another interesting question presents
ITSELF 1t is regarded as certain that the
earth has not grown seDsibly colder with
in the last two thousand years. Though
it daily receives an immense amount of
heat from the sun, yet its radiation throws
temperature. But if, by reason of it's con-
tact with comets matter, it should re-
ceive an additional supply of heat, how
long time must elapse before it gets
down to its former temperature?
I remember that when I was young the
old people used to say that the winters
were not then as cold as they had former
ly been. I mentioned this to Prof Henry
of the Smithsonian Institution, and he told
me that there was reason to believe
that there were, at intervals of about thirty
years, periods of greater cold for q few
years at a time. He did not seem conf
dent on this point, however. But we do
know from the revelations of geology that
in the past times the earth has been much
warmer and also much colder than it now
is. At one time tropical plants and ami
mails existed far in the northern regions,
while at another period immense masses
of ice visited South America. What pro-
duced these changes? Again. I have
often wondered what became of the peo-
pie who built the North American mounds
and the massive structures found in Central
America and elsewhere. It does not seem
probable that such people could have
been exterminated by the savage sribes
that our ancestors found on this continent.
Again, the works seem to be too recent
for the people who built them to have de-
cayed and perished from want of fur-
ther vitality in the stock, as geology
shows that other races of animals have
done. l was formerly inclined to attribute
their destruction to some great volcanic
disturbance that threw out an immense
Quantity of noxious gases that terminated
their existence.
Is it not, however, probable that in the
earth's motion part of it came in contact
with some noxious cometary matter, which
for time covered that side of the globe,
but which was not abundant enough to
spread itself over the whole surface of the
earth?
I have, however, perhaps extended
these suggestions sufficiently to invite the
attention of astronomers and other men of
scientific attainments to the interesting
questions connected with the subject
r. L. Cliaegnadn IN Neac York San, Jan.
4th
How TO DETECT INCIPIENT SMALLPOX
While isolated cases of smallpox are
being discovered in various parts of the
city, it may be Of interest to know how to
defect the disease. DR.. Robert D. Nc
Mary gave a Globe-Democrat Reporter
the following as infallible: ''The feeling of
tiredness and pain in the back are almost
universal and prominent symptoms, but
the one thing that distinguishes small -pox
from every other is the hardness of the
eruption. By pressing and passing the
hand over the forehead or legs, the feeling
is exactly that which would be caused by
medium-sized shot being buried under the
skiD an1 tho covoritv of tho d;sooso NOV