Marshall County Republican. (Plymouth, Ind.) 1856-1878, 1872-06-13
Curious and Scientific

-Hc~SH"t9 INC PetOct.y q IIOtGtt0n.-
Prof. A. E. Dolbear suggests, in the
American Journal Of Science, a simple
and effective method of determining
the velocity of rotation of wheels and
shafts. Upon the face or upon the
periphery of the rotation object, he fas-
tens smoked paper, and this he touches
with point of rubber which is attached
to one branch of vibrating tuning
fork, having known rate of vibration.
The fork is to be SO held that the direc-
ton of its vibrations will be at right
angles to the line of motion of the shaft.
By counting the number of undulations
made on given extent of the smoke
paper, the speed of rotation is at once
indicated. Thus, if the fork makes 100
vibrations in a second, and one vibra-
ton is recorded on TIE smoked paper
in a space covering olsae.half of the cir
conference of the wheel or shaft. or
two vibrations within the entire circum-
ference, it is evident that the rate of
rotation is fifty revolutions per second.
By this simple and easy method, the
velocity of rotation of gryoscope disks
and all kinds of shafts and wheels NAV
be readily aseertained.
Why Lace is Costly.-The finest speci-
men of Brussels lace is SO complicated
as to require the labor of seven persons
on one piece, and each operative is en-
ployed at distinct features of the work.
The thread used is of exquisite fine
ness, which is spun in dark, under
ground rooms, where it is sufficiently
moist to prevent the thread from sep
arating. 1t is so delicate as scarcely to
be seen, and the room is Sc arranged
that all the light admitted shall fall
upon the work. 1t is such material that
renders the genuine Brussels ground so
; costly. On piece of Valenciennes
not two inches wide, from two to three
hundred bobbins are sometimes used !:
and for a larger width as many as eight
hundred on the same pillow.
Porous FGlters.-In the course of an
examination of filters, at the instance
OF the British Medical Journal, Professor
Wanklyn has had proof that filtration
through beds of porous materials in
cludes very powerful chemical action,
albuminoid matter being instantly re-
solved into ammonia and other products
by the action of the filters, which, in
deed, behaves in this respect like a
boiling solution of permanganate of
potash. A good filter is a sanitary en-
CINE OF great power.
Velocity Of Soand-Mr. J. E. Stone.
astronomer royal at the Cape of Good
Hope, has experimental on the velocity
Of sound from the discharges of the /
o'clock signal-gun at the castle, the two
observers being 14,S08 feet apart. and
| m IA n "a al l. l. i
graph. The result indicates velocity
of 1,O90.6 feet per second at freezing
temperature.
Habits Of Ducks.-M. Trevers SAYS that
the blue duck of New Zealand does not
exhibit solicitude for the safety of its
young like other ducks. DR.. Hector
extends this characteristic absence of
fear to most of the native New Zealand
birds. Darwinians account for these
facts by supposing the arrival of man
on the islands to be so recent that in
stlnctlve fear has not been developed.
Woody Fiber DISSOLVED. Il igniuc, or
cellulose, the chemical constituent of
woody fiber, has been regarded until
recently as insoluble. Our clothing
wears away, but no amount of washing
leaves any portion of its solution. 1t
has, however, been found that the fluid
"cupro ammonium" is ready solvent,
so that the old problem of making
planks out of saWdust is no longer a
mere jest.
Fires From, Heat Pipes.-Wherever iron
pipes are employed for conveying any
medium, such as smoke, hot air, steam,
or hot water, they should not be allowed
to pass through woodwork unless pro-
tected by an earthen crock. The iron
rust may be deoxidized by heat, and
upon reoxidizing it often becomes red
hot. Many fires have occurred from
this cause.
Another Great Invention.-The inventor
of hydrate of choral has introduced a
new organic compound called croton-
chloral, by which, it is claimed, the
head may be rendered insensible while
the other parts of the body remain I'M
affected. 1t promises to produce all the
good effects of hydrate of chloral, with
out any drawbacks.
Sponge Paper.-Sponge paper, made
by adding finely divided sponge to pa
per pulp, is used in France for dressing
wounds. 1t absorbs water readily, and
retains moisture for a long time, and is
applicable il the arts and sciences.
"A paste made of wheat -four or corn
starch is more satisfactory than any
gum mucilage for scrap books. A little
spirits of camphor or diluted carbolic
acid will preserve it for considerable
time from molding or securing.
DIR. Blake, President of the Califor-
MIA Academy of Sciences, considers that
the most remarkable feature of the wa
Jers in the Yellowstone geysers, is the
| enormous amount of ammoniacal salts
which they contain.
! Drowning OF an AerOnaut.
Prot. Atkins, attached to Lipmans
/ Queen CITY CIRCUS which exhi h;tod "a