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


ry before The MECHANICs INSTITUTE
OF New York, has been published in that
city, and receives the favourable motto,
OF The press The following extract W.,
copy from the Evening Post and en-
doIse The editors remarks lba, the read
a, will not tind il too long;
mention these facts only in the hop'
Of showing you thai there is pleasure
io studying the sciences, and when W,
come 10 Natural History we shall find
the study Of that still more amusing
The animal and vegetable worlds are
well worthy of observation. Probably
youall know what is meant by cyci0ia
ll we make a spot on the periphery oil
u wheel, travelling on plane, the tx
vore which that spot describes is a eye
loid: Now, there ia no figure in which
body can be moved with go much
velocity and such regularity of speed,
not even the straight line. Malhema
ticans discovered this not many years
ago; but Nalure's God taught it 10 thu
Eagle before mathematics were invent,
ed: and when the eagle pounces upon
his prey, he describes the figure of .
cycloid.
A globe placed in waller, or in air, in
moving meets with resistance, and i;s
velocity will be retarded. If you alter
the globe to the folm Of an egg, there
will be less resistance. And then there
is a form called the S0lidQf least resist.
dnce, which mathematicians studied for
many years 10 discover il, they found
they had the form Of fsh's head!
Nature had 'rigged CUT 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 to be mos
efficient 10 assisting flight. The human
eye has mirror on which objects are
reflected, and a nerve by which these
reflections are conveyed 10 the brain
ard thus we are enabled to take an in.
terest in what passes before the eye
Now when The glass is too convex, we
use one kind OF glasses 10 correct the
fault, and ifit be not convex enough, Of
il we wish 10 look at objects at a differ,
ent distance, we use glasses Of entirely
different description.
But as birds cannot get spectaces
Providence has given them method ol
supplying the deficiency. They have
the power of contracting The eye, oI
making it more convex, so as TO see th,
specks which fioatin the atmosphere,
and catch them for food, and also for
shatteniHg the eye, 10 see TO great dis"
,ance, and observe whether any vullure
or any other enemy is threatening ,o
destroy them. In addition 10 this they
have q film, or coating, which can bt
suddenly thrown over The eye 10 prolec
it; because al the velocity with which
they fly, and with the delicate texture
Of lhe eye The leas, speck Of dust woull
&C, upon il as a penknife thrust into III,
human eye. This film is 10 protect lh
eye and the same thing exists 10 SOM
extent in the eye Of horse. Th
horse has large eye, very liable tt
take the dust. This coating in ih'
horses eye is'called the haU or ,hir'
eye lid, and if you will watch closel,
you may see il descend and return, witt
e'ecro velocity. 1t clears away tn,
dust and protects the eye from injury
1.-THE eye should catch cold, the hav
hardens, aud projects, and ignorant per
sons cut it of, end thus destroys hi
safegard.
You all know if you take pound O
iron, and make Of il a rod foot long
what weight it will support. But if
be hollow rod it will support weigh
many times greater than before. Ma
ture seems 10 have taken advantage O
this also, long before mathematician
had discovered it, and all the bones o
animals are hollow.
The bones o! birds are large becaus
they must be strong 10 move their larg
wings with sufficient velocity; but they
must also be light, in order 10 Goat essi
ly upon The sir, Birds also illustrate
another fact in natural PHILOSOPHY. |
you Isieoa bag and make it air ligh,
and put thunder ."sler, il will sup
port great weight, say 100 pounds
But twist il or diminish the air in il
and ii would support no snch weight
Now a bird has such an air.bsg. Whe'
he wishes 10 descend, Re compres,es
at will, and falls rapidy: when he woul'
rise he increases it, and floats with ease
lie also hes the power Of forcing air in
10 The hollow parts of his body, ant
thus 10 assist in his fight. The sam