Amador ledger., 1909-11-05

To prevent overspeeding, an English
municipal ordinance requires high
power automobiles to be equipped with
an apparatus giving warning of the ex-
cessive rate or one automatically con-
trolling the speed. In the first appara-
tus, the piston of cylinder is con-
nected with the driving mechanism, and
the air it congresses at normal speed
escapes silently through two peripheral
vents, but with greater speed the air
pressure pushes back smaller piston,
exposing whi sting vent, through which
some of the air is forced with a loud
whistle. A device of the second type is
an oil-pump, with a pipe having three
way cock. AS the speed gets too high,
centrifugal regulator opens the third
channel, and thus causes the oil to be
forced into cylinder where it presses
against brake piston, reducing the
vehicles speed BY adjusting the re-
gulator spring, the normal limit in
dicated on dial-can be set at any de-
sired rate.
Sheets of bamboo are a useful product
that the Society Islands are beginning to
export. In eastern Tahiti, where the
material is abundant, the bamboo, in
two-section lengths, is brought down
from the mountains by men, and pre-
pared for use by the women. The pro-
cess, as described by Consul J. D.
Dreher, begins with cutting out the
joints, leaving pieces of cane or 3
inches in diameter and 2 or feet long.
The hard outside coating is trimmed off,
the'cane is soaked days in water, and
each section is then split down one side,
opened out and pressed at. After
further trimming to quarter of an inch
in thickness, the woman skllfully splits
the slab into three or four sheets. The
finished sheets, dried and smoothed, are
& to inches wide and about 80 long,
very white, so thin as to be almost tran
sparent, and retail at 5 to 20 cents each.
The scattered sunlight of the sky be-
ing polarized, M. Salet, of the Paris
Observatory, finds that it may be sup
pressed by Ncol prism in front of a
telescope. The prism allows direct,
unpolarzed light to pass, and in this
way fifth, magnitude stars are made
visible in full daylight.
In determining position by means of
sextant, as in the case of an observer
at the North Pole, the altitude of star
or the sun is measured from the sea-
horizon, or from an artificial horizon
when the natural one is not visible. IT
is often impossible, however, to get &C
craute determinations, and an error of
half degree in the observation means
displacement of location of about 30
miles. Prof. c. V. Boys, the British
physicist, proposes to insure greater
accuracy under difficult conditions by
measuring the altitude from vertical :
instead of horizontal-base. A vertical
swinging telescope, suspended on gim-
bal frame and weighted so as to
swing steadily in a period of about one
second, is mounted in an upright tube
forming the handle of the instrument,
and the ordinary parts of small seXtant
are attached. When a star is brought
under observation, its image in the
vertical telescope, or collimator is
shown against fine scale in the focal
plane of the lenses. When properly
calibrated, this scale may show the
stars altitude by direct reading, with
out calculation, and the precision may
be so great that the observer, sitting at
table, can show his position within one
minute of arc, or about mile. The
instrument is expected to prove of
special value to aeronauts.
Certain kinds of cast iron are known
to grow on repeatedly heating and
wrought iron contracts. From an in
vestigation by Profs, H. F. Rugan and
H. c. Carpenter, it appears that carbon
is the chief cause of the growth.
For an alloy to retain its original con-
dition they suggest white iron, with
about per cent of carbon and only
slight proportions of other constituents,
including not more than 0. 2 to 3. per
cent OF silicon. The problem is not fully
solved, but the Investigators seem
justified in advising white iron instead
of ordinary grey cast iron-which con-
tains some uncombined carbon-as a
material for annealing ovens and other
purposes where change after many heat
ings would give trouble.
In the novel method of distribution stan
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