Amador ledger., 1907-06-21

The tempering of special steeIs for
modern tools requires very high tenn
peratures, with absence of carbon air
and gases likely to alter the hot
metal, and to ensure exclusion of
active chemical agents an improved
electric tempering furnace has been
constructed in Berlin. The steel Is
heated in fused salt, barium chic
ride having proven most suitable.
The furnace is square box of iron,
asbestos and tirebricks, and the
interior is filled with the salt and
opposite iron plates serving as cleo
trodes for the alternating current, the
temperature being accurately con-
trolled by pyrometer and rheostats.
In chamber about 619 inches square
and Z inches deep 3>pound piece of
steel was heated to 1900 degrees G. in
81 seconds. Working ten hours a day
at the maximum of 1900 degrees c.,
the furnace requires two pounds of
barium chloride each day, a new lin
ing once year, and iron electrodes
somewhat oftener. The fused salt
scales off as the steel is plunged in
the cooling liquid.
The fiber of the dwarf palma tree
until lately regarded as worthless or
harmful-is developing an important
Algerian industry. Factories are
multiplying, and to these the natives
bring the palm leaves, which are
transformed into vegetable fiber by
steam cardlng machine, and then
spun and braided. The material has
the advantage over horse-hair of being
proof against moths and insects. 1t
is being used for mattresses, woven
products, harness and carriage work,
military bedding, various tissues, and
even hats.
Though many plans to lessen the
jar of machinery have been tried.
annoyance from steam hammers, etc.,
continues. A new French remedy Is
to place under the machine a Pinch
elastic plate consisting of two sheets
of steel with an intervening layer of
coach spring surrounded by felt.
Better control of high temperatures
is increasing our list of useful mater
ials, the latest additions-specially
brought to notice at the late CONVEX
sazione of the London Royal Society
being pure iridium and rhodium
and fused silica. Hitherto rhodium
and iridium have been practically
unworkable metals, but they have
been SO purified as to be quite MALE
able, and have been made into such
apparatus as basins, tubes and TASKS.
Having very high melting point
and being almost unattached by
acids, the metals promise to be of
great value for special purposes.
Silica, which was first fused with
great difficulty into crude tubes
several years ago, is now melted into
viscid liquid, and by suitable means
is converted into apparatus as attrac-
tive in appearance as ordinary glass,
while the cost has been greatly lessen
ed. The abundance of the material
and the extraordinary properties it
possesses give unusual interest to Its
products. Dishes of silica can be
suddenly cooled from white heat
without risk of cracking, they soften
only at extremely high temperature,
and-unlike vessels of ordinary glass
they are quite unattached by water
or acids.
The amusement sensation of the
near future is to be a submarine
botanical and geological garden, with
arrangements to enable excursionists
to view its wonders. Pine, the
Italian inventor whose diving boat
experiments began in 1900, EpredIcts
that it will become as easy to visit
depths of lou yards in the sea as tt
take an automobile ride, and he fore
sees that such trips will be very
popular. He finds an entire absence
Of any sense of being submerged. The
common notion that sunlight doei
not penetrate 100 yards is incorrect,
and there is sufficient light even OF
cloudy days to show the smallest
objects OF fine print.
The necessity of a lamplighter fol
gas lIghted streets has been removed
by James Hepburn, an Englist
plumber, who applies an attachment
so adjusted that mere regulation Of
the pressure at the gaswoIks either
lights up the lamps automatically Oh
reduces the flame to a small piIo
light.
The property of certain substance
known as "trIbo- Iuminescence, ;
which is an emission of light OF
breaking or crushing, seems to b.
very different from ordinary phos
phorescence, and in an investigation