Spirit of the age. [volume] (Woodstock, Vt.) 1845-1913, 1904-10-15
ALUMINIUM INDUSTRY.
MANIFOLD USES OF THIS RE.
MARkAsLE METAL.

| SVo tVGaPs
| The history Of the metal aluminium
and its use in the arts is peculiarly
illustrative Of the method of industrial
! development, aided and fostered by
scientific research says the New York
| Evening Post. For three.Quarters OF
century the metal was scientific
curiosity, but the appearance of de-
mand for 1t resulted in the almost
immediate perfection of methods for
| Its extraction, whereby its cost was
so reduced as to make ii available for
common uses.
! AS long ago as 1907 Sir Humphrey
Davy conjectured the existence of
metallic element as q component or
clays and alumina. In 1928 German
chemist, Wohler, actually separated
] the metal from -its-oa,nnn,,,air.--
discovered its remarkable physical
properties of lightness, toughness and
ductility. But for more than 60 years
no use was found for aluminium, be-
yond an occasional employment OF
very small quantities in the construc-
tion of scientific apparatus. At the
| centennial exposition in 1876 q sur
veyor's transit made of aluminium was
exhibited, but its remarkable lightness
was even less astonishing than the
value placed upon it-aluminum was
then about six times as expensive as
silver.
Naturally, In the progress Of engi.
nc f,,x, tpti
| guished the last quarter of the 18th
century, the attention of inventors and
constructors was attracted to the new
metal, and 1t was freely predicted that
much use would be made of it, II its
cost could be reduced so that 1t might
compete with cheaper materials OF
struction. Weighing only about one
third as much as an equal bulk OF
brass or copper, it resists most acids,
| has a white lustre, Is an excellent con-
ductor of electricity, and is possessed
| of many other desirable qualities.
Here, then, was the incentive to in
| ventors, and many chemists set out to
| discover method for the economical
extraction of aluminium. Its ores exist
in great abundance, common clay con-
tanning large proportion Of the
| metal; but OF all substances these
| very ores seemed most refractory and
! least amenable to chemical treatment.
A number of processes OF purely
chemical nature were devised, but
none Of them reduced the cost Of pro-
duction to such point that the metal
could compete with steel and brass as
an element of construction.
At last process was found that is
both simple and cheap. 1t was discov-
cred that cryolite a mineral found in
great quantity in Greenland, and con-
sisting almost wholly of aluminium
| flunrida WAC -oaoily melted, and that
In its fluid state it dissolved crude
alumina as readily as water dissolves
sugar. A powerful current Of electric
ity passed through this molten mix
ture was found to extract the metallic
aluminium, and the process was also
seen to be regenerative; that is, the
cryolite is not consumed, Lut is used
over and over the molten bath be-
ing supplied from time to time with
crude alumina. This material exists
in nature as mineral, named bauxite,
after the town Les Baux, near Aries,
in the south of France, where deposits
of it are found Vast beds Of it exist
also in Arkansas and elsewhere IN this
country.
The smelling process is of the sim
plest. In an iron vat, about the size
and shape Of an ordinary bath.tub, is
melted a charge of cryohte, gas fur.
mace supplying the necessary heat.
When the charge is melted, powdered
bauxite is stirred in, and an electric
current Is turned on between cast-iron
electrodes immersed in the mixture.
The electric current furnishes enough
heat to keep the mass melted, and the
liquid aluminium collects at the bot
tom of the bath, whence it Is tapped off
from time to time Once started, the
process is continuous until the dirt
and impurities collected in the vat re.
Quire 1t to be drained and recharged.
Aluminium extracted by this process
at Niagara Falls. at Kensington, Pa,
at Foyers, in Scotland, and at numer-
GUS establishments on the continent
of Europe took it's place in the arts
Immediately. AS an element of con-
struction, however, it did not meet the
expectations of its earlier advocates.
1t was found to be difficult to work,
cumming the teeth of files and stoutly
resisting cutting and drilling tools on
account of its toughness. But new
uses at once developed The German
army >investigated it. and found that
helmets of aluminium, as light as felt,
would turn the glancing impact of q
bullet. Its military uses are almost
innumerable. Besides helmets, but
tons, cooking utensils, canteens, cart
ridge cases and clips, sword and bay
onet scabbards-in short, almost all
metallic accoutrements-aren now made
of it. The French government built
a torpedo-boat of it, but sea water at
tacles the metal, and it is not believed
that it will find much use in marine
work. Notwithstanding, the blocks,
cleats and some other metallic parts
of racing yachts have been made Of it.
1t has been used as substitute for
tinplate as roofing material. Max.
ers Of Photographic apparatus and op.
tical goods use it largely, and 1t is
rapidly displacing tin as a material
for bottle caps, boxes for druggists
use, etc. An extensive market for it
is furnished by makers OF fancy goods
souvenirs. medals and tokens and toi.
let articles, such as combs.
But the largest use was found In an
unexpected quarter. Aluminium has
62 percent OF the electrical conductiv.
ity Of copper. Hence a wire about one.
eighth larger in diameter than a cop.
per wire will conduct equally we'll
and at the same time will weigh less