New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1873-08-02
APPLIED SCIENCE.

PRESERVATION OF RAILROAD. 1uS,--lTeutltu "
Dresden suggests the following for any kind of
wood firm enough for ties. They first to be air
dried as thoroughly as possible, without consuming
too much time and then placed in chamber grad
nally warmed until they become hot. They are
then, while as hot as possible placed in suitable
inpregnating vessel, filled with thick heated coal
tar under pressure until thoroughly saturated and
are placed upon and strewed with screened sand,
coal ashes, or the like, and dried. When perfectly
dry they are examined to see whether they are
coated thlcly enough and every crack hlled Win
the tar; If not, this is remedied by brushing with
hot tar. The impreenating composition should be
similar to that employed in the manufacture OF
roofing paper-namely condensed coal-tar, with the
addition of natural asphaltum and some sulphur,
the latter impartng tendency TO harden more rap
Idly. The spikes, when driven, should be dipped ~
hot coal-tar, and any split opened should be wen
coated with IT,
Its but three years since the German chemists,
Graeb and Liebermann, announced that they bad
succeeded IN producing alizarn-the coloring mat
ter of the madden root. in the laboratory-a dis
covery which, though at the time it had very dis
tant possibility of attaining practical Importance
was yet hailed by the chemical world as note
worthy triumph of science Since that time, great
advances the result of much and laborous expert
mentation, have been made in the direction OF Civ
ing practical and commercial value TO this impor-
tant discovery the consequences of which to be
estimated from The fact that to-day the artificial ma
tcrial be supplied TO the market at prices below
those asked for the natural madden. In the City OF
NewYOTk there recently purchased several tons
Of the artificial azarin at price p per cent cheaper
than il could be manufactured from the madden.
II is said that the rapid growth of the manufacture
has already caused distress among the producers OF
madder In those regions of France and Germany
where Its cultivation forms almost the entire means
Of subsistence OF the inhabitants.
CONVENTION OF RAILWAY MASTER MECHANICS
AsSOCIATIoN.-'rhe American Railway Master Me-
cbanics' ASSOCIATION recently held its sixth annual
convention in the city of Baltimore. The attend
was somewhat larger than at the Boston meet
ing of last year. though it has been pronounced to
have been less teresting. Many subjects of ihpOr
lance TO the railroad engineer and TO the public Were
discussed, among which may be named the inyesti-
CATION OF boilers the comparative value of fnes, the
action OF the sandblast on copper, steel, and iron
the economy and efficiency of pOwer-brakcs narrow
gauge railroads, the resistance of trains &c
With regard to the question of the merits of
power-brakes. the opinion of the members was
uniformly favorable. The Westinghouse, as the
best known apparatus of this class, came in for a
good share of attentiOn-the committee having the
matter in charge expressing the opinion that the
saving in expense with the air brake, with regard to
the wear and tear of the wheels and other ma
chlnery, is very great and justfes its use from an
economical standpoint. The safety of passengers
also demands its use, in addition to which the COM
mittee deemed that much OF the complaint against
the complicated nature of the apparatus arises from
the fact that il Is Yet a thing. The air-brake
was ON the whole, recommended as being the best
brake yet In .... .-... ..i.-0....
ANTHRAPURPURIN, A NEW AIIzARIN DYR-Mr.
William ii. PeIkn, to whom we owe so much for
his researches among the anilne colors has lately
communicated q paper TO the Chemical Society of
London upon Anthrapurpurin, in which be remarks
that his attention has for some time been directed
to artificial Alizarin, with view of eliminating
certain associated colors and utilizing them in the
arts. He has now succeeded in separating one of
these, and making and Introducing it to notice un
der the name of AnthrapurpuTin. His method con-
ssts in dissOlving the crude colOring matter in
dilute carbonate of soda and then agitatng the re-
snltng solution with freshly preciptated alumina,
which combines with the alizarn, leaving the an
thrapurpurin in solution This is filtered from the
alzariD liquid, heated to boiling and acidlfed with
hydrcchlorc acid. The coloring matter which is
present As collected on filter, washed, and dried.
The anthTapuTpuln thus obtained is very impure.
being associated with q substance which dyes
alumlna mOrCant of orange color land which is
now under investigation, as well as with anthra-
havie acid, etc. Perkn gives method for obtaining
apure anthrapurpnrin and as the result of numer-
ons inquiries, ne hnds that IT has about the same
affinity Tor mOrdants alzaTin, and that the colOrs
II produces are analogous TO some extent as it pro-
duces red with aluInna, purple and black with iron
wOrdants IL is, however in many respects superior
10 azarin as the reds much purer and less blue
than those of alizarin, while the puppies buer
and the blacks more intense. The fastness of the
coofs against soap and lights quite equal to that of
aliZaIln. When used TO dye turkey-red it produces
very brilliant colors of scarlet shade, which are OF
remarkable pernanence Specimens presented in con-
nectlon with the communication of Mr.. Perkin show
decided superiority aizarin in the purity and
brightness OF the proper color.
TIRE GRAMME Magnetic ELECTRIC MACHINE-The
prize Of 5000 francs offered by the Societe dEncour
agenent of Paris for apparatus giving an electric
current constant in direction and intensity, the
electrOmotiye force and the resistance of which
should be comparable to that of nitric acid bat
terry of 60 to 50 cells of the ordinary SIZE and which
should be superior, both in economy and healthfu
ness, to any thus far produced, has Just been
awarded TO the magnetoelectrc machine invented
by NJ. Gramme. THIS apparatus, therefore, merits
brief description. II consists of horseshoe mag.
net, between the poles of which revolves a ring of
iron, lying in the vertical plane with the mag
net itself. This ring is entire and is wound with
covered wire in sections, the ends of which termi-
nate in rods arranged about the transverse axis on
which the ring turns. Upon the ends of these rods,
as the ring rOtates, press successfully two copper
discs, one each side of the axle, which serve as
the electrodes. The current developed by the rota
tiOn. due entirely, Gangan has proved, to the
motion Of the helces, is continuous and uniform in
direction. BY using electromagnetic instead of
permanent ones, and by adopting Ladds principle
Of TeentOrcenen the power OF the machine has been
vastly increased. machine OF this sort, in daily
use for electro-plating in the establishment of NJ
Chrlstofe IN Paris weighs 400 kilogrammes of which
135 kllOgTammes are the weight of wire on the per-
manent magnets, and 40 kilOgTammes that on the
movable ones. About 0nehorse power is required to
give IL its normal velocity Of 800 turns minute.
With this velocity, the current is equal in intensity
10 that of two Bunsen cells of the ordinary size and
In quantity TO 81 such cells: II will deposit 600
grammes Of silver per hour With this velocity. the
femDeTafupp a pYPnpls r.