Burlington hawk-eye. [volume] (Burlington, Iowa) 1845-185?, 1849-12-20
Interesting Facts in Sci nee.

While peruslng, recently, Mary Som-
erville's connection Of the Physical Sci
ences,'' which, by the way, is admitted to
be one Of the very best works upon scien-
tific matters in existence, we marked sun
dry paragraphs for publication. As SCI
e,difc Investigations and the lacts brought
to light through these investigations, are
beginning to attract the popular attention,
we think that our extracts, (simple facts
though taken at random, will he perused
with interest by all. In treating Of the
internal density of the earth, the author
says:
"Proressor Leslie observes that air
compressed into the fortieth part of its vol
ume has its elasticity fifty times augment
ed. If it continues to contract al that rate,
would, from its own incumbent weight,
acquire the density Of water at the depth
of thir,y-four miles. But water itself
would have its density doubled at the
depth of ninety-three miles, and would
even attain the density Of quicksilver a:
depth Of three hundred and sixty-two
miles. Descending, therefore, toward the
centre, through nearly four thousand miles,
the condensation Of ordinary substances
would .urpass the utmost powers Of con-
ception.' DR.. Young says that steel would
be compressed into one-lourth, and stone
into one-eighth of its bulk, at the earth's
centre.'
In treating of the division Of time, the
author says:
The division Of the year into months is
very old, and almost universal. But the
period of seven days, by far the most per-
manent division Of time, and the most an
cient monument Of astronomical knowl-
edge, was Used by the Brahrnins In India;
with the some denominations employed by
us, and was alike found in the calendars
of the Jews, Egyptians, Arabs and As
syrans. 1t has survived the fall OF em=
pires, and has existed among all success
size generations, proof of their common
origin"
"No circumstance in the whole science
of Astronomy excites deeper interest
than its application TO Chronology" "The
| ancient state Of the heavens may now be
computed with great accuracy, and by
comparing the results Of calculation with
ancient observations, the exact period at
which they were made may be verified II
true. or if false their error may be detect
ed"
"Thus the Chinese had made some adj
vances in the science Of Astronomy at the
early period (llO0years before the Chris
tian Era.) Their whole chronology is
founded on the observation Of ec)'pses,
which prove the existence Of that empire
for more than 47OO years."
y "The epoch of The lunar tables OF the
Indians, supposed by Baily to be 5000
wears before the Christian era, was prov
ed by La Place, from the acceleration Of
the moon, not TO be more ancient than the
time of P,olemy, who lived in the second
century after il. The Indians had deter
mined the mean motions Of these two plan
els (Jupiter and Saturn) in that part o
their periods when the apparent mean mo-
ton of Saturn was at the slowest, and ina
of Jupiter the most rapid. The periods
in which that happened was 3loZ year
before the Christian Era, and the year lay
after it,
"Eudoxus, a contemporary Of Plato
mentions star situate in the pole of tn
equator, and il appears from computation
that k Draconis was not very far from tha
place about 5000 years ago; but as it i
only cbout 2l5O years since Eudoxus liv
ed, he must have described an anterio
state of the heavens, supposed TO be IN
same that was mentioned by Chlron. aoo'
the time Of the siege of Troy. Thus ever
I circumstance concurs in showing that as