The National tribune., 1891-01-08
SCIENCE CHAT.
Nen IdsAs AMI Tsefnl linz.

NEW WAY OF ASNEALfNG STEEL.-Heat the
pieces rs slowly As possible, and when at low
red heat put them between two pieces Of dry
boards and screw them up tight in wise. The
steel burns its way into the boards, and on
coming together around il they form q practi-
cally air-tight charcoal bed. When il cooIs of
the steel is apt to be found thoroughly an
Standardization Engineer.
The EIFFEL TowER.-Thc Eifel tower Is 70
be utilized in obtaining a very high pressure BY
means Of tube running from top TO bottom
and filed with mercury. NJ. Ca'liett, who has
already distinguished himself by liquifying
different gases-such rs oxygen and nitrogen
by means Of high pressure. is to employ the
tube for similar purpose. twill give press
urs at the bottom Of some four hundred atmOs-
pheres.
FINDING A CRACK ~ METAL.-A crack in a
piece Of metal is prevented from extending
further by the well-knOwn means OF drilling a
hole where the rent ends but when the hole
is not bored on just thatspOt the crack Is apt to
continue beyond the hole. To facilitate the
search Of the exact point Rsrus LHdusiriells
recommends mOistening the cracked surface
with petroleum, then wipe il and then imme-
diatcly rub it with chalk. The oil that has
penetrated into tho crack exudss and thus in
dicates with precision where the crack stops
american Engineer.
WHAT Is CELLULOID? -The substance known
as cellulOid consists usually Of dissolved paper,
says the American Architect, although cotton or
other vegetable fbers may be used. In the
manufacture, tissue paper is treated with nitric
and sulphuric acids, the product Il then washed
and camphor added. The mass is then ground.
COloriEg matter is now added and the mass Is
made into n paste with alcohol: il is then
pressed and broken between rolls. The finished
mass Is very plastic and may be moulded and
pressed into any desired shapes, drawn into
tubes etc. All the celluloid articles sold in the
United States, and in fact the bulk of all that
are sold the world over, is the product OF an
American cCmpany's factory. The output OF
the company last year was valued at 81 ,5OOO 900.
NOVEL FLYwHEEL.-We read in an eX-
change of q novel hywheel. The hub Is Of cast
iron, and in the place Of spokes two disks built OF
steel plates are bOlted TO the hub. The wheel
so made is about 20 feet in diameter, and around
the rim 20 tons Of steel wire are wound, each
strand being under a TENSION Of 80 pounds. The
strength ofsuch structure is immensely greater
than that OF an ordinary east-irOn wheel; in
fact, it is difficult 10 imagine such wheel burst
ing. Tho Ogter ibers OF the wire rim would
probably part first, and thus give warning OF
the coming danger. At all events, this par
ticular wheel, 90 feet in diameter aud weighing
20 tons, is run at a speed Of 2i0 revolutions a
minute 40 that the rim travels mile every II
seconds.
NJ cEOhE.-E.siiOtt9 metnO0 OF dnulHilb-
/ ting smoke from boiler and other furnaces ia
now being shown on the Thames embankment
near the City Of London Schools. The method
consists in drawing the smoke from the smoke
box by fan. and delivering it into box halt
| filled with water By means Of rotary paddle
the water is churned up into a spray, through
/ which the smoke passes. The object is TO wash
the carbon particles out of the smoke, together
| with the tar. ammonia, and sulphuTic acid, and
to let nothing escape but invisible and inodor,
Gus gases. As far as can be judged, this result
IS very fairly attained, but the apparatus is toe
/ small for q really adequate test We under
/ stand. however, that the invention can be seen
/ applied TO boiler Of 100 horse power and thai
/ it has been found that the increased amount o.
! fuel required to drive the fan which produce:
the artificial draft is twoand- a half per cent. o
| the eOHsumpiion.-EH Engineering, London.