The Bossier banner. [volume] (Bellevue, Bossier Parish, La.) 1859-1952, 1880-01-15
USEFUL, AND SCIENTIFIC.
PHoroGRApHs IN NATURAL Color

PHOTOGRAPHS IN NATURAL CoLoRs.
Captain Abney, the well known En-
glish photographer, has succeeded in
obtaining pictures Of the solar spec
trum in its natural colors, both on silver
plates and on compounds of silver held
in place by collodion. The photographs
are produced by oxidation of silver
compounds when placed in the spec
trum, the coloring matter being due APP
parently to mixture of two different
sizes of molecules of the same chemical
composition, one of which absorbs at
the blue end and the other at the, red
end of the spectrum; and the sizes of
the molecules are unalterable while ex-
posed to the same wave-lengths as those
by which they were produced. Captain
Abney believes that the colors may be
preserved unchanged when exposed to
ordinary daylight. He has thus sue
,ceeded in explaining the action by
which Becquerel some years ago, OBJ
tanned photographs in colors as pro-
duced by oxidation, and not due to in
terference.a lBecquerel's photographs
were fugitive; Captain Abney appears
to have succeeded in ssfixing" his. An
exposure of two minutes with wide
slit was sufficient to produce the pictures
of the spectrum. b@9@ ssilsp-
FRENCH METHOD OF FLOORING. -
The improved method of laying down
floors which has been adopted in France
is, it appears, obtaining wide applica-
ton. The plan consists in simply put
ting down the flooring, not, as COM
monty, on joists, but in imbedding the
boarding in asphalt floors as these
being found particularly adapted. among
other examples, for the ground stories
of barracks, hospitals, churches, court
houses, etc. According to this method,
pieces of oak, usually two and one half
to four inches broad, twelve to thirty
inches thick, are pressed down into a
layer of hot asphalt not quite half an
inch thick in the well known herring
bone pattern. To insure a complete adj
hesion Of the wood to the asphalt, and
obtain the smallest possible joints, the
edges of the. pieces Of wood are planed
down beyeling toward, the bottom, SO
that their cross, sections becomes wedge
like. Nails, Of course, are not ineces-
sary, and a perfectly, level SURFACE may
be given to the flooring by planning after
the operation of laying down. Some of
the advantages of this flooring, which
only requires an even bed on which to
rest, are the following: Damp from be-
low and its consequence, rpt, are pre-
vented; floors may be cleaned quickly
and with the least amount Of water, in
suring rapid drying; j. verminf have no
tn lok Aho n%c
and unhealthful exhalations from the
soil can not penetrate through. ss,d 10
> The MOTIyE POwER.7The various
matters which an animal eats consists
of pure fUod-stnffs and 1of useless con-
comitant bodies; just as coal consists of
pure fuel and Of the useless mineral mat
ter known as ashso When, an animal
eats his dinner the process of digestion
and assimilation takes place, and has
the ultimate result of separating the
pure food-stuffs from the useless con-
comitants. The latter bodies are re-
jected at once, but the. food-stuffs are
taken up with his veins. incorporated
with the blood (which consists Of food
in different degrees Of combustionJ and
used for building up the various portions
of his body. Supposing the animal
were mere growing object like ascrysl
tai, with no work to, perform and no
consequent waste Of material, the
process would stop here, and the. crea-
ture would wax bigger and bigger from
day to day, without any alteration in
place or ,redistribution- of assimilated
matter. But the, animal is essentially a
locomotive machine, and the purpose
for which he has taken in his, food il
simply that he may use it up in pradue.
ing motion. For a while he slows il
away in his MUSCLES oriays it. Eby fol
future use. as fat !; but its. ultimate desti1
nation in every instance is just as truly
to be consumed for fuel as is the cast
with the :, coal in, the. steam zen
gine. The food, however, oh1y
gives us one-half of the necessar1
materials for the liberation of dormanl
energy. Oxygen is needed to give tis
the other half. This oxygen weitake in
whenever we breathe Animals like
| fishes or sea-snails obtain the necessary
supply from the water by means oflgillsa
for large quantities of oxygen are hello
in solution by water, and the needs b
such comparatively sluggish creature
are not very. great. With them a littl,
energy goes a long way. Air-breatk
ing animals like ourselves, ,aon the othel
hand, need relatively large quantities o
the energy giving gas in order to keel
up the constant movements and Aigl
temperature of their bodies. Such crea
lures accordingly take in the oxygen b,
| 9 IL - - IL. y. ekl