The daily exchange. [volume] (Baltimore, Md.) 1858-1861, 1858-05-20
sCIENcE Ann ART

BEAUFUME's GAs-FLAME FURNACE This is a
new French invention, in which, instead of burn
ing the tuel directly below the boiler, M. Beau
fume first transforms it into gas, in separate appa
ratus, and then conveys this gas to the boiler,
where its complete combustion causes the genera
ton of the steam. This separate apparatus, which
is termed gassifer, consists of furnace construct
ed very like that of locomotive, with water
space substituted for the tubepate. Coal is heaped
upon the tre-bars to a considerable nelght-say
70 to % inches, according to the qualty OF the
coal. The air necessary for the gasshcatlon Is sup
piled in suitable quantities below the hre-Dars Dy
means of n blowing fan. The oxygen of the air
supplied very active combustion amongst the
lower LAYERS of coal in contact with the fre-bars,
converting the coal into carbonic acid gas; and this
gas, in passing through and amongst the upper lay
ers, which ought always to remain black, becomes
converted into carbonic oxide, and accumulates in
the upper part of the furnace, mixed with nitrogen,
and doubtless hydrogen also. These gases, the tenn
perature of which is but slightly elevated, are con-
Quoted to the boiler through wrought iron pipe
and enter the boiler furnace, after having been
thoroughly mixed, in chamber termed the burner,
with suitable proportion of air supplied by the
blowing fan. After having been once ignited in the
boiler furnace the gases continue burn as fast as
they supplied. The flames produced act on the
heating surface of the boiler and the gases remain
ing after combustion pass through the ues and es-
cape into the atmosphere under the pressure due to
the blowing fan; no chimney being required.
Iron TARGErs.-We find an interesting account
of some experiments which have been made at
Woowich, Eng, to test the power of resistance
of timber lined with four inch iron plates and also
to test the durability and quality of iron plates manu-
featured by rolling, as compared with iron turned
out by the hammer. The target was an immense
construction of timber, lined with four-nch plates
of iron, of both descriptions, and the total weight
was thirty tons; it was placed on foundation made
for the purpose, and twenty-four rounds of GS
Founders were fired. The first fourteen rounds
fired at distance of six hundred yards, and,
after the first few rounds, the timber work gave
tbn1n
fired at distance of four hundred yards and the
work of destruction commenced was thus consum-
mated. The timber work of the target was com.
pletey broken and spntered, and the plates of iron
made by the rolling process were cut up and split
having apparently but little adhesion The iror
plates which had been made by the old process re
sisted the solid wrought iron shot much more sue
cesstnlly, making it evident that these plates pos
sessed more adhesive power than the rolled plates
1t is believed that the principle of combining tim
Der with iron plates is the best than at present
be adopted; but such plates must be improved upon
in order to resist the conclusion of repeated dis
charges of heavy shot,
ATMOSPHERIC Observation-Disclosures Faradav ha.
published some of the very important results of hi
Investigations into the phenomena of atmospheric
magnetism. According to these Investigations tho
effect of the approach the retreat of the sun il
his daily is to produce such variations in thu
temperature and expansion of the atmosphere
as to influence the lines of force emanatng from
the EARTH both in their direction and intensity; and
the manner in which this influence will be de
veloped Is, by means of figures and descriptions
stated by Professor Faraday in relation to the an
nual and daily variation, and the irregular pertur
bations of the magnetic force, which, he thinks
are consequences of it. He then applies, in con
firmaton of his hypothesis, the results of the va
rious magnetic observations which have been made
and, by aid of the observations, the Professor en-
dcavors to indicate what different changes in thu
inclination, decinaton, place of the SUM- land anC
sea. DC, will produce; all the phenomena however
indicating that the sun does not act directly on the
needles at different places, but mediatey through
its effect on the atmosphere. Professor F. considers
that the varying pressure of the atmosphere the
currence of winds and large currents of air. of rain
and snow, of the passage of those masses of warn
and cold air which the meteOrolOgst recognizes in
the atmosphere, and of the aurora borealis NAV all
produce changes in the lines of magnetic force anC
become less sensible in the records of ire
gular variations.
CONSTRUCTION OF ROADS AND PAvEMENTs-M
Marie de Pous, of Paris, has invented process fol
the combination of certain substances, and the en-
ployment of certain modes, applied to the construc
ton OF roads, streets, pavements and ways for the
running of locomotives. The processes consist
chiefly of spreading thin layers of materials sucl
as lronstone in granular state, and then watering
and rolling, repeating the layers to the requisite
thickness. In certain cases, solution of suIphate o.
iron Is used for watering, and the ironstOne com
bincd with volcanic schistus gluten. The sub
stances best suitng this formation of pavement ar,
iron ore, in slate or stone, reduced to small chips
granulated cast iron, either broken or in chipping
or shavlngs; iron or other metals reduced to pieces
all ccments and hydraulic lines; lime plaster, sand
stones, iron dresses, sags, etc.