The Bolivar bulletin. [volume] (Bolivar, Hardeman County, Tenn.) 1865-1888, 1879-10-16
USEFUL AND SCIENTIFIC.

ulSliI6CIa0J 1OF OrulnafY use. 1t Is IN Il
convenient form, and is inexpensive.
When sprinkled about in dry state, it
slowly decompOses, and sets the chloride
free, which passes into the atmosphere,
and destroys any decaying organic mat
ter, which contains the germs of disease,
floating about in the air. Where there
is fear of sewer gas in houses, the free
use of chloride of lime is great safe
guard.
POULTRY FATTENING APPARATUS
At the Kilburn (England) Agricultural
Exhibition was an apparatus shown by
M. Odile Martin for fattening poultry.
This most ingenious apparatus revolves,
and includes several rims or shelves,
which are divided into separate COM
partmentS for about two hundred birds.
These are tied, but with full liberty in
their own pen. 1t is connected with a
feeder which contains the food to be
forcibly consumed by the unfortunate
poultry. From this patent feeder is ap-
pended a mOuth-piece, and as each bird
revOlves in its turn the operator places
the mOuth-piece in the throat of the
bird, sets his foot on a pedal, and at
once the food is forced into the stomach.
The food is liquid, composed of barley
meal and maize mixed with water. Its
said the birds do not suffer, and the OPP
Grafton is very rapidly accomplished.
In an hour one man can feed five hun
dred birds.
VISUAL EFFECT OF ELECTRIC LIGHT.
Professor Cohn of BreSIau mas been
lately making experiments with the cleo
trio light on the eyes of a number of
persons for the purpose of testing its in
fuence on visual perception, and the
sensation of color. He has found that
letters, spots and cOlors are perceived at
q much greater distance through the
medium of electric light than by day or
gaslight. The sensation of yellow was
increased sixty-fold, compared to day.
light; of red, six-fold and of green and
blue about two-fold. Eyes that could
only with difficulty perceive and distin-
guish colors by daylight or gaslight were
much aided by the electric light, and
the visual perception was also much
strengthened. Professor Cohn concludes
from this fact that electric light would
prove exceedingly useful in places where
it is desirable that signals should be
seen at a great distance. The engine
used was Gramme's electromagnetic
apparatus, which rotates 600 times in
minute.
USE OF SOFT CoAL.-For years no
one supposed that lump of soft coal
dug from its mine or bed possessed any
other property than that of fuel. Itwas
next found it would afford a gas which
was combustible; in process of time me-
chanical and chemical means were
found to manufacture this gas (carbu-
retted hydrogen) and applying it to the
lighting of buildings and cities. In do
ing this products of distillation were de
4 f,II
ents are manufactured from it: First, an
excellent oil to supply lighthouses,
equal to the best sperm oil, but at lower
cost; second, benzole, a light sort of
fluid, which eyapOrates easily, and COM
bined with Vapor or moist air, is used for
the purpose of sO-called portable gas
lamps; three, naphtha, a heavy fluid,
useful to dissolve gutta percha, India
rubber, etc; four, an excellent oil for
lubricating purposes; five, aSphaltum,
which is a black, solid substance, used
in making varnishes, covering roofs,
vaults, etc; SIX, paraffin, white, crys-
tallinc substance resembling white wax,
which can be made into beautiful wax
candles; it melts at temperature of
10 degrees, and affords an excellent
light. All these substances are made
with soft coal.
MEASUREMENT OF DIsTANCES.-A
new instrument for measuring distances
by sight is among the recent inventions
in England. In this arrangement, the
distance of any object is ascertained by
simply reading off upon a scale marked
on the base of right angled triangle
the number of divisions which are equiv
alent to the angle of two lines of sight
| denoted by an index scale; the two sides
of the triangle-that is, the perpendicu-
| lar and the hypOthenuse-ar the two
! lines of sight to the object, and the
! length of the base varies with the dis
tance of the object observed at the apex
of the triangle. The distance of the
same is measured by the length of base
required to enable the line of sight to
meet the object on the oblique line. The
Oblique line of sight in the instrument is
obtained along a radius arm, the angle
of which to the base may be set at
pleasure. The part of the instrument
forming the other line of sight at right
angles to the base has sliding action
along the base, so as to enable the latter
to be heightened or reduced, but is al
ways at right angles to it. For the
base, a space is divided of 6.2S2 inches,
thus allowing the decimal readings of
the length of the base to be obtained
6.2S2 being the proportion of circle cir
cumference to radius. A scale is pro-
vided by means of which the radius arm
may be set for oblique line of sight to
the decimal of a degree. The process
of reading off the distance Of an object
on the instrument is in this wise: As the
chord of arc of an angle is to the radius
as / to 57.35, then if the radius arm be
57.35 inches, it follows that for an angle
of one degree it will be one inch out OF
perpendicular to the base. The oblique
line of sight, being along the radius arm,
will, therefore, meet at 57.35, the per
pendicular line of sight with one-inch
base, and the Object-at the apex of the
triangle-will be distant 57.35 inches
from the observer, that is, 57.35 times
the length of the base line The base
line being divided to scale, the distance
of the object may thus be read off.