Clearfield Republican. [volume] (Clearfield, Pa.) 1851-1937, 1874-04-15
Animal Motion.

Niiiiutn = 'irOWDTiuBe uciVereu tnc
thirteenth lecture of the course to the
mechanics, at the North Sheffield Hall
in Prospect street, New Haven. Tho
lecture was full of interest and was
amply illustrated by skeletons, dia-
grams and modes The following is a
brief synopsis of his remarks.
Without the forcc of friction we
would be unable to sit on chair or
walk the floor. Without the noun.
tains would at once become level, and
indeed all nature would cease to ex-
list. There is a spider who spins 4
thread so long that its friction in the
air is so great that it sustains the lit
tlc animal at the end of tho thread
By this means he is enabled to stretch
a line between points one hundred feet
apart. f4
The source of power in animals il
muscular contraction, and the posses
sion Of this faculty separates animals
from vegetables. The muscles are
composed Of q large number OF punches
of extremely small threads. Each
thread is connected with nerve, the
nerves entering into the spinal column
and thus connecting with the brain.
By some means, Us yet undiscoy cred,
when the animal wishes TO move
muscle the command is teegraphed
from the brian through the nerve 10
the muscle, and the contraction takes
place. m
The cuttlefsh moves by means of
the application of the principle of the
hydrostatic press The body of the
fish is enclosed in sack, by the OK
pansion Of which it is filled with wa
ter, which enters through valve 20
arranged as TO prevent the water from
going out. When the fish wishes TO
move, IL contracts tho sack, and tho |
water is forced very powerfully ont of
a small tube connected with tho sack.
This jet striking against the water OF
the sea, propels the fish. The tube is
generally pointed forward, and so the
fish moves, backward, but If the ans
NAL moves forward, il directs the tube
backward and il turns around with
great rapidity by the same Means
The larva Of the dragon-Hy has a sim
liar contrivance for locomotion The
principle of the hydrostatic press is
also used by the heart in sending the
blood all over the body. The pro
grcssion OF fish in water is due not
to the simple lateral motion of the tail,
but to the fact that the tail is flexible,
and thus presents an inclined plane to
the water, which, by its action on it,
produces forward motion. This was
illustrated by toy boat with a model
OF fish's tail attached 10 it and opcr-
atcd by machinery. When placed in
a trough of water, tho boat progressed
quite rapidly, to the delight of the
audience. Tie forward motion of
bird in fight is duo to the same cause.
When muscle is contracted and is ..
held in that position, the fibres of the
vibrate 80 times per second,
and this produces decomposition of !
Tho material of tho muscles which
must be supplied by the blood from
.he heart. When this process goes on
or some time, fatigue occurs.
A person that becomes fatigued by I
thirty miles would be equally S
atigued walking twice as fast whom r
10 had passed over six mlos. 1t is v
computed that young man in boat Q
ace in an cight.oarcd outriggcr does
'ach minute an amount Of labor of G
our foot-tons, or equal to lifting four I
ons one foot. o
Tho tail Of ono species of tho shark b
, connected with tho body by ball o
nd socket, or universal Joint, by [,
nenns of which the tail moves through n
he water obliquely as an orr in scuI- Y
ng a boat. 1t is this that enables d
he fish TO mako the enormous leaps T
Or which IL is noted. Il
The English hunting horse and tho Ii
rey-hound havo immense muscles on Il
10 shoulders. This Is because tho tc
're-legs have to sustain the force not IL
My OF the animal but of the great ii
'omentum acquired in their long and b,
,pid legs. A fast race horse makes ii
bout two and one-half leaps per sec sc
nd, passing over about twenty five ca
ct in that time.
The lecture closed with tho exhibi.
on OF drawing of tho skeletons of pl
irlous animals by means of the store dc
,ticon From them we learn that: lo
Iho.rhnoceros has three toes. This du
'imal stands on its toos and not on Bl
20 whole foot. su
The elephants legs arc very straight th
I'd hence it cannot move rapidly. II II
n, however, stand without fatigue
: on immense length OF time.
The leapipg animals jump by sud. ch
My strengthening their legs, which cr
o supplied with powerful muscles ap
: their purpose American Sports m,
f"' 10