Amador ledger. (Jackson, Amador County, Calif.) 1875-19??, 1910-09-30

MISCELLANY
Reported weekly for the Ledge

Reported weekly for the Ledge
Measuring Bullet Flight-The Gas
Weighing Balanced Carrying Science
Over the Empire Sprayed Metal
Films-A Powerful Motor-A Novel
Lightning Arrester The Work of
Smoke Using-The Century Clock
Waterproof Concrete.
The speed of rifle bullets can be de-
termined by the improved method Of
Crantz with such precision that the
error is estimated not to exceed one
foot per second. A series of electric
sparks at the rate of 5000 per second
lights up the bullet as it passes a hori-
zontally pivoted rotating drum covered
with a Photographic film, and the dis.
lance apart Of the images formed on
the film show the bullets velocity,
the frequency of the spark and the
rate of the drums revolution being
known. To make measurements easier,
a glass rule divided into millimeters is
photographed with the bullet at each
spark. The reduction of speed by air
friction5 is shown from the lessened
space apart of images of the bullet on
a second drum, and the lag of the
image of the second drum gives the
time of flight between the two.
special arrangement is made for
synchronizing the drums and identify
ing the images on each. A pendulum
contact breaker closes the electric
circuit that fires the rifle, and cuts off
the current except during the minute
fraction of second in which the bull
let is passing the drum.
The super-sensitive balance of Sir
William Ramsay has short beam and
slender supports of silica and the tray
is supported by hair of silica The
instrument is kept in special metal
lie case in an underground chamber.
A tiny mirror reflects point of light
to black scale six feet away, and the
slightest DETECTION of the beam is
made penceptible by movement of the
light along the scale. The release
from a tiny tube on the tray of xenon
gas known to weigh only $4,000, 000,
600 of an ounce was registered on the
scale. The limit of possible smallness
in metal weights seems to be reached
in Sir Williams aluminium strand,
finer than hair, and 1-25 inch long,
weighing IL, 400, 900 of an ounce.
The British Association for the Ad-
vancement of Science has met twice
in Canada, and once in South Africa.
Its 1914 meeting is to be held in Aus
tralia.
The new spraying process of deposit
ing metal films, the invention Of u
.Schoop of Zurich, seems to be adapted
to wider range of applications than
any other method of producing protec-
tive coatings. The electrolytic pro
cess coats iron and other metals with
covering of gold, silver, nickel,
copper or zinc, and has come into ex
tensive use for plate goods and for
electrotypes used in printing. Iron is
also protected from the atmosphere by
galvanlzing, or dipping into molten
zinc, and by thinning in bath of mol
ten tin. Sherardizing is the improved
process of Cowper Coles, and gives a
beautifully adherent deposit of zinc on
heating iron articles in contact with
zinc to about 200 deg. c., or more
than 200 deg. below the melting point
of zinc. In the Schoop process, the
metal for deposit is liquefied and
sprayed as fine mist upon the surface
to be coated. Compressed nitrogen
or other inert gas may be used to pro-
duce the fine spray, and, while the
molten metal mnst come from the
MOBILES at a temperature of several
hundred degrees, the mist itself is
found to be not hotter than 40 deg.
to so deg. C. The projected PARTICLES
strike with such force. however, that
they are welded together into a
homogeneous coating. Various metals
may be deposited, and the GOODNESS of
the mist makes it practicable to coat
inAammable substances, such as
paper, wood, cellulsid and wax. The
coating is harder than films produced
by rolling. Among numberless APP
plications suggested are the coating