Southport telegraph. [volume] (Southport, W.T. [i.e. Kenosha, Wis.]) 1840-1850, 1845-04-07
4 xT r act
From an Adfrpss delirered before the He
chanicS' Institute of INcr York.

From an Adtress delirersd before the he
chanics' Ilstitute-ef Ncr York.
The animal and vegetable worlds IRE
well worthy Of observation. Probably you
all know what is me nj by cycloid. II We
make a spot on the periphery ola wheel,
travelling on a-plane, the figure which that
spot describes is cycloiJ. Now, there is
no figure in which abody can be moved
with so much velocity ard such regularity
of speed, not even the straight line. Ma
ihemnticans discovered this not many
years ago; !, but Natures God laugh; il io
tie eagle before mathematics were Invented
and when the eagle pounces upon his prey
he describes the figure of a cyclod. -
a globe placed in water, or in air, IL
moving meets with resistance, and It's We.
lociy will be retarded. Ii you alter the
globe TO he form of an egg, there will be
less resistance. Andhere is form called
the sold of Least resistance, which mathe'
naicians studied for many years to disco
vel; and when they had discovered 1t, they
found they had The form Of q fish's head
Nature had "rigged out" the fish with jus'
such figure.
The feathers Of birds, and each particular
part Of them, are arranged at such an argyle
as 10 be most efficient in assisting flight -
The human eye has Il mirror, on which
objects are reflected, AMI nerve by which
these reflections are conveyed to the brain
and thus we are enabled Ia take an interest
in the objects which pass before the eye.
L. 81.
one kind of glasses TO cosrect the fault; and
if it be not convex enough, or if we wish
TO looh Il. objects al Il different distance, we
use glasses of entirely another description.
But rs hi. DIS cannot get spectaces. Pro.
violence has given them a method of sup
plying the deficiency. They have the
power of contracting the eye, Of making il
more convex, so rs TO see the speeks which
foa, in the atmosphere, and catch them for
food; and also Of Hat,ening the eye, 10 see
TO a great distance. and observe whether
any vulture or other enemy is threatening
to destroy them. In addition TO this they
have q film, or coating, which can be sud
denly thrown down over the eve TO protec;
i, because ct the velocity with which they
fly, and with the delicate texture Of then
eye, the least speck Of dust would act upon
it as pcnknile thrust into the human eye.
This film is to protect the eye, ADD the same
thing eX SITS To some extent, IN the eve Of
the horse. The horse has large eve,
very liable to take dust.-This coating in
the horses eye, is called the har, or third
eyelid, and if you will watch closely, you
may see i, descend and return with electric
velocity 1t clears away the dust and pro-
tects the eye from injury. If the eye
should catch cold, the haw hardens and
projects, and ignorant persons cut it off,
and thus destroys this safegard.
You all know, if you take pound of
iron. and make of it a rod foot long what
weigh, il will support. Bot if it be a hol-
low rod it Will support weight manv
times greater than before. Nature seems
before ma.hemalicians had discovered it,
and all the bones Of animals are hollow. -
the Lones of birds are large, because they
must be strong to move their large wings
with sufficient velocity; but they must also
be light, in order to float easily upon the
air Rirda also illustrate another fact in
natural philosophy. If you take bog,
make it air tight, and put i, under water. it
will supper; large weight, say an hun
drel pounds. But lwis, it, or diminish the
air in ii, and ii supports 20 such weight
Now bird has such an airbag. When he
wishes to descend, he congresses it, and
falls rapidly; when he would rise he in
creases it, ard floats with ease. He also
has the power of forcing air into The hol-
low parts Of the body, and thus TO assist
his fight. The same thing may be observ-
ed in fishes. They also have an air-bag
TO enable them TO rise or sink in the water
ill they find their proper temperature.