The news and herald. (Winnsboro, S.C.) 1877-1900, 1880-03-25
SCIENTIFIC,

| SCIENTIFIC.
Jaso6s(n's Method for Photo Prtnttng.-
Prepare u carbon picture in tho usual
I manner upon sheet Of glass, and sur
round tho picture with wooden frame
which exactly fits round the sheet Of
glass. Then pour into the frame u
mixture (not too hot) one part Of gela-
tine, ono part OF gum arabic, and two
parls OF glyccrinc. When tho mass has
stifcncd In tho frame, carefully re-
move the latter troE; the former with a
knife, and with equal care invert. the
gelatino pla'e, with which tho carbon
picture will now be Incorporated. To
Ink the picture use Il ground glass roller,
and the linking process proceeds most
favorably when done upon smooth
elastic support like that used for rolling
letter press forms. Tho printing ink,
which must be worry thick, Is previously
dissolved In oil of turpentinc or In
benzolc, and some Of tho solution,
without the addition of varnish, Is
poured upon the plate and distributed
over It by the glass roller. The plate
being linked, sheet of uncoagulated
alDumcnized paper corresponding in
siz, to the picture is laid upon it, and
an Indla-rubber roller passed softly
across the paper, which Is then lifted
off the plate. The albumenlzed paper,
which absorbs moisture readily, should
not be allowed to lie too long upon tho
plate for fear Of the albumen disSolving
Off and dirtying tho plate. 1t Is not
necessary to damp the plate with water,
as 1t possesses sufficient moisture to
allow of dozen Impressions beng
taken. or course this moisture Is eX-
a of loS l.ut Iva nj latn 10
cicntly hygroscopic to absorb enough
moisture from the atmosphere in the
course of few hours to allow Of print
ing being resumed. While IN other
llchtdruck processes the image Is sunk
into tho plate and the ink has to sink
into the shadows, this method has the
advantages OF furnishings relief which
facilitates printing. BY this process,
also, round objects, such rs bottles and
vases, can be- printcd-possibly with
colors, which could be burn in.
Endless Ru,is.-Tho idea Of making a
train lay down and take up Its own
rails as itmoyes along is not anew one,
but an inter esting realization of L. Is
now TO bO witnessed in the Jardin des
Tullcrics, Paris. The system is that
Of Clement Ador. The rails OH either
SitO vi viz Sall VI Il
series Of joined pieces of rail, with flat
system Of wheels, passing down over
tho front and up over tho end wheels,
and all tho wheels have two tlanges to
prevent any dCrailmcnt. In front the
era rs OF rail are guided by two distri-
buting wheels, which arc governed
by the traction, so that Oh pulling obli-
Iucly, right or left, tho endless way
automatically follows tho samo direC-
ton. At tho end of the first train,
again, are two taking up wheels, pro-
yidcd with uiifercnliul motion to meet
the difficulty Of going in curves, which
involves All extension of tho rail on
one 81 &c and IL contraction of that on
tho other, SO that whatever tho curve
to six or seven metres rudiu-; the way
is regularly put down and lifted
From the mechanical point of view ono
Is struck with the smallncss of the
force required to move train thus ar
ranged. In the Jarlin des Puileries
the train consists of three carriages,
capable of containing in all thirty
children, and often full. These are
| drawn by two goats, which work thus
tor seven hours. The total load is
about 1000 kilosrammcs, or rather
more than ton. TO draw like
weight in three carriages on ordinary
roads would require Il dozen goats,
four Tor each vehicle. CIhis Is the
number harneSscd to the small carriages
for children in the Champs EIysccs }
The economy of carriage. then, Is in
conteStable, Tho normal speed is four
miles, per hour. Tho system Is, of
course, not designed for passenger
traffic, but for goods, and in many
places, with bad roads or no,c, might
bc very scrviccahlc.
Il SubStt:EtG for Gutta- -Perchd.-Ac-
cording 10 the Pplytcchuic R.ric,c rival
to indla-rubDcr and gutta-Dercha has
been found IN q new .lastic gum which
has been named Balata. This is the
Milky sap Of the Dully-tree. that ilou-
rlsh.s Oh the banks OF tho Orinoco and
the Amazon In South America. The
operation OF winning the gum is simi-
lar III every respect to that employ cd
with caoutchouc and gutta-percha. 1t
resembles gutta-pcrcha SO closely In its
general properties that much Of it Ia
shipped from Guiana and sold yearly
for a-porcha-although it has many
| points Of superiority. 1t is tastelcss,
gives an agreeable odor on being
warmed, may be cut like gutta-pcrcha
IS tough ana lcathery, Is remarkably
flexible, and far more elastic than
gutta-percha. 1t becomes scft and
may be joined piece to piece, like
gutta-pcrcha, about l20 degrees Fab.
but requires 270 degrees Fab, before
melting (highcr that guta-pcrcha). 1t
Is completely soluble in benzole and
carbon disulphidc In tho cold. Tur-
pcntne dissolves it with the application
OF heat, while 1t is only partially solu-
bic in anhydrous alcohol and ether. 1t
becomes strongly electrified by friction,
and is better insulator Of heat and
electricity than gutta-pcrcha, on which
account 1t may find considerable appli-
cation for electrical and telcgraphic
uses. Caustic alkalies and conccntra-
ted hydrochloric acid do not attack it
but concentrated suiphuric and nitric
acids attack 1t rs they do gutt.- perch /,