The Lexington intelligencer. [volume] (Lexington, Mo.) 1901-1949, 1903-11-14
SUBSTITUTE FOR PLATINUM.
InvIr, a New Alloy, Useful in Max
ing Fine Instruments.

4N RAAAE0A A9N9 W
which themetalplatinum has been
put during the last 20 years is in
the manufacture of incandescent
electric lamps. In order to con,
meet the outer wires with the ear
bon flament inside the globe, ii
has been necessary to introduce
short sections of a material which
had the same rate of expansion
with heat as the glass stem on
which the flament was mounted.
If this substance expanded either
more or less thar the glass, it
would quickly become detached,
and a leakage of air into the globe
would result, after a few changes
of temperature. Platinum met
these requirements s%plendidly.
The growing scarcity of that metal
of late years, however, has stimu-
lated the search for something
else which, while a good conductor
of electricity, also showed the
right expansion with heat.
A certain alloy of nickel and
steel, in which the two are com.
bined in the proportions of Sc
parts of the former to Ga of the
latter, is said to have shown the
proper qualities, and is being used
as a substitute for platinum. A
French writer, DR.. Guillaume,
makes this announcement in an
article which has been translated
for the American Manufacturer
by Charles A. Brassler, of Brook
Ign, N. Y. The Frenchman gives
to the alloy the name "invar,"
says that it has been known in
Europe since 1897, and furnishes
some additional facts, which Mr..
Bressler puts in the following Ian.
guage:
ut came into use cautiously at
first, because it was feared that
an alloy having such a property
would reveal some hidden defect
which would render it useless, but
it is now employed extensively.
The geodetic measurements ex.
ecuted during the last year or two
have almost all been made with
the aid of instruments, the essen.
tial parts of which derive their
principal qualities from the new
alloy. The geographic service of
the French army has adopted it,
and the photographic service of
the navy and the measurements of
bases made by the French commits
sions in Madagascar, Tonkin, and
Congo, as we'll as in Bolivia and
elsewhere, have been effected
with apparatus made of invar.
"The new alloy has been used
also in measurements in Cape Col.
ony, and in those of an expedition
Of Russian and Swedish scientists
in S~pitzbergen from 1899 to 1901.
Similar apparatus has been con.
or is in course of con-
struction for the geodetic service
OF Germany, Japan, Mexico, Rou-
mania and Russia. All the results
attained confirm the optimistic
predictions founded on the expert
ments of the laboratory.
GIN a different direction, the
adoption of the new alloys has al.
lowed of marked progress. Very
encouraging results were report.
ed to the International Chrome.
metrlc congress, which met at
Paris in 1900, and since the success
has been confirmed. Thus, almost
the prizes of the Observatory
of Neufchatel have during the
year been awarded to two watch.
makers who have utilized these al.
and several manufacturers
Of astronomical regulators, espe.
in Germany, have complete
ly abandoned the old system Of
compensation in order to adopt
definitely the pendulum having a
rod of invar."