Year: 1861

FURNACES FOR THE DIsrILLATIoS OF Coal
An invention, the object Of which is 20 obtain, by
a simple and improved method, perfect carbon
izaton of coal-that is, free from all its tarry and
volatile substances, and also an actual distila-
ton by collecting each of these substances sepa-
rately, by means of an apparatus placed over the
oven-has been patented in France, and is highly
spoken Of


The apparatus is so constructed as TO yield be-
sides coke, essences, oils. gases, and even coal
black or smoke black so that no substance is lost
in the process of coking. The improved oven Is
so arranged that the flame produced in the fur
mace rises into straight inclined fiue, and then
at the bottom Of the oven divides into two
branches, right and left. The two branches or
columns of fame thence pass each into semi-cir-
cular fiues hat built in the manner of laby-
rinth, and they finally descend into an under
ground fiuc the orifice of which is at the center
of the circumference of the oven. The two col.
umns of flames thus heat on their passage the
sole on which the coal lies, thus exposing it in its
entire extent to the action of heat. The oven is
charged in such manner rs to leave sufficient
vacant space for the products of distllation. The
two columes of fame, after having descended into
the underground fue are converted into one col
umn OF smoke, which passes into chambers there
to leave its solid particles in the shape Of smoke
or coal black.


In the distilling apparatus, number of coke
ovens being set in a line, there applied to
their orifices cast iron pipes having cap or
dome, into which the substances developed by
cooking enter. These pipes have elbows by
which they join large main pipe, and in which
the products collect. There are also other devi-
ces for accomplishing the purposes of this ingen-
ious invention.


SILvERISG Brass AND CoPPER-An ingenious
method of silver plating with silver leaf is prac
tced by the French with great success The ar
tcle to be plated is first raised to red heat. and
then plunged into dilute nitric acid until il be
comes bright and clean. After this, its surface
is rubbed with pumace stone and hot water and
it is then again heated to such a degree as to
make slight kissing sound when it touches wa
ter, in which state it is dipped again into dilute
aquafortis which bites its surface and makes IL
little rough so to retain the silver leaf when
applied. The article is now heated on a warm
iron plate called a mandrin, until it acquires a
blush shade, when the operator lays on two
leaves of silver, and rubs them down with steel
burnlsher. After these two leaves are thus fas-
tened ON, the article is again placed on the man
drin and heated as before then four additional
leaves are laid on and FURNISHED in the same
manner. These operations are called charging,
and as many as thirty, forty, fifty, or sixty leaves
are thus laid on, according to the soldity of the
silver plating desired. The whole surface is final
ly FURNISHED with great pressure. Articles oi
copper and iron can be silvered in the same man.
ner, only the iron is not submitted to the nitric
acid acton-its snrface is first thoroughly clean
ed, then roughened with file for the reception Of
the silver.


A very thin coat of siver can be put upon brass
or copper with a mixture of chloride of silver
chalk and pearlash, in equal proportions; the sur
face OF the brass is first made perfectly clean af
| ter which this mixture is slightly mostened Will
water and rubbed on with a clean rag. OF cours,
this is not very durable, but it answers for som,
purpose. Another method consists in applying
IN the same manner. moist mixture of one par
OF silver powder, two of cream Of tartar, and thu
same quantity of common SALT When the sur
face Of the brass is entirely covered with silver,
Is washed IN tepid water containing a small quan
tity OF pearlash, then washed again in warm sof
water, and finally wiped and dried at FIRE.
BorLER MAcHIsrRY.-The ash pits should b
cleaned out every watch, and the ashes throwI
overheard, picking out first any humps of coal tha
may have fallen among the ashes. When no
running at full speed. a portion of tho cinder
may be thrown upon the fires again, after damp
ing them with little water. So, also, shoul


hne bltuminous coal be dampened before beinI
supplied to the furnaces-for though il does tax
a iissie heat from the FIRE to evaporate the waite
mixed "itc the coal, a saving Is effected, by pre-
venting the coal from being drawn. PARTICULAR
in boilers with strong draft, through the flues an
lodged in the connections, or out of the smoke
pipe. -
Smoke-pipe stays also require to be looked Q
occasionally, when made of rope, as they grow


little slack from time to time. These should a


ways be adjusted while the pipe is hot: other
wise, If they be set up while the pipe is cool, th
expansion after it becomes heated will, in a


probability, carry either the stays themselys
away, or the band securing them to the pipe L


a gale of wind, when the ship is rolling heavily


these stays should be looked to, in order to tight


en- any Of them that may have become slack, o


as to throw the strain alike on all. Hemp rop


is very inferior article for such purpose as stay


for smoke pipes; good wire rope is much better.
Crate bars, when fitted new, are usually allowe
plenty of play, both fore and aft and sidew.sk


to allow for expansion when they become heatc'