The Columbia Democrat. [volume] (Bloomsburg, Pa.) 1837-1850, 1845-06-07
SCIENCE.


Of New York has been published in lhs
city, and receives the favourable motto,
of The press The following extract W,
copy from the Evening Post and en-
do,se he editors remarks that the read
-sT will no, find /, too long:
mention these facts only in the hop,
of showing you that there is pleasure
in studying The sciences, and when WE
come TO Natural History we shall find
the study Of that still more amusing
The animal and vegetable worlds arr
we'll worthy of observation. Probably
you all know what is meant by a.cycioid
Il I'VE make spot on the periphery OF
wheel, travelling on plane, the FIX
rure which that spo, describes is eye
lo!d! Now, thereis no figure in which,
body can be moved with so much
velocity aad such regularity Of speed,
not even the straight line. Malhema
ticisns discovered this not many years
ago; but Natures God taught il to the
Eagle before mathematics were invent
cd: and when the eagle pounces upon
his prey, he describes the figure of .
cycloid.
"A globe placed in waller, or in air, 10
moving meets with resistance, and is
velocity will be retarded. If you alter
the globe 10 the form Of an egg, there
will be less resistance. And then there
is a form called the solido Of least resist
.dnce, which mathemalicians studied for
many years TO discover it, they found
they had the form OF fsh's head!l
Nature had 'rigged QUIZ the fish with
just such figure.
The feathers Of birds, and each birds,
and each particular part Of them are ar
ranged in such an angle as 10 be mosl
efficient in assisting flight. The human
eye has mirror on which objects are
reflected, and nerve by which these
reflections are conveyed TO the brain
and thus we are enabled 10 take an in
terest in what passes before The eye
Now when the glass is too convex, wei
use one kind OF glasses 10 correct theI
fault, and if il be not convex enough, OF
If we wish 10 look at objects at a differ
~ent distance, we use glasses Of entirely
different description,
But as birds cannot get spectacle.
Providence has given them a method OIL
supplying The deficiency. They have
ahe power Of contracting the eye, oil
making it more convex, so as to see tn,
fpecks which float in the atmosphere,
and catch them for food, and also forl
fattening the eye, 10 see TO a great dis
Htance, and observe whether any vulturej
or any other enemy is threatening ,ol
destroy them. Ia addition 10 this they
have a film, or coating, which can b,
suddenly thrown over the eye 10 proiec
il; because at the velocity with which
they fly, and with the delicate texture|
of the eye The least speck Of dust would
sctupon Il as penknife thrust into The
human eye. This film is to protect The
eye and the same thing exists 10 some
exientin the eye of a horse. The
horse has large eye, very liable TO
take the dust. This coating in the
horses eye is'called the ha,o or third
eye lid, and if you will watch closely
you may see il descend and return, with
e'ectro velocity. 1t clears away the
dust and protects the eye from injury |
1.-THE eye should catch cold, the haw
hardens, aud projects, and ignorant per-
sons cut it of, and thus destroys his
safegard.
You all know if you take pound of
iron, and make of il rod foot long,
wha, weight il will support. But if i'll
be hollow rod it will support a weight,
many times greater than before. Ma
ture seems TO have taken advantage oil
this also, long before ma'hematicians
had discovered it, and all The bones ofl
animals are hollow.
The bones o: birds are large because
they must be strong 10 move their large
wings with sufficient velocity; bu, rtheyl
must also be light, in order 10 float easi-
" upon the cir. Birds also illustrate
another fact in natural PHILOSOPHY. IfI'
you is1e bag and make il ain tight.
emu Putdtunder water, il will sup.
port great-weight, say 100 pounds.
But twist il or diminish the air in il,
aud i, would support,no such weight.
Row bird has sueh,an air.b bag. When
ne wishes 10 descend, he congresses it
at will, and falls rapidly: when he would
rise he increases it, and floats with ease.
Ha also has the power Of forcing air in.
20 the hollow parts of his BODY, and
A hits In aSsiSt in his Aiob, ~