Amador ledger., 1907-04-05

peratures. = A Locomotive Tha
Does Not Pull Its Train. -t'aIIur,
of Hail-Shooting. = Fire Damp
Sounds. Unnecessary
A Novel Museum.
The alloys of copper and alum mum
likely to prove useful have been
shown by an important British in
Vestigation to be few in number, the
valuable ones being chiefly those rich
IN copper. Those having from IL to
95 per cent of aluminium give least
practical promise. The alloys rich
in copper rank high in quality, and
those having from to 10 per cent of
aluminium are remarkably similar in
physical and mechanical properties to
certain high grade steels, which they
even surpass in certain respects. An
important discovery is that the
widely aluminium bronze, d"
containing 10 per cent of aluminm.
has as great tenaolty and ductiIity in
the form of small chill castings as in
the rolled bar. Small quantities of
aluminium are found to have a strik-
ing influence, and one-tenth of l per
cent raised the angle of twist In
copper in torsion 80 per cent, lower
Ing the electrical conducting % per
cent.
A remarkable photograph taken in
Brussels street by Z. DE Heen
shows curious luminous effects from
each of the arc lamps at the instant
of a lightning flash. Bands from the
lamps to the ground are thought to
have been caused by conduction
currents, but the effects also include
two luminous tlaments emanatlng
from each lamp, one forming a closed
curve and the other having a lasso-
like curl at its extremity.
As safeguard against defective
construction, Plauen, Germany, pro-
hibits the building of walls and
sewers with cement, or using con-
crete, when the temperature at a. m.
is below % degrees F., and with lime
at q degrees. When freezing delays
hardening OF concrete, the wooden
frames must be kept in place until
the end of the cold weather.
The so-called, "Renard train.'
which is already being used for carry
ing farm products on the roads near
Roulogne, consists of series of six
wheeled trucks running behind, but
not drawn by a gasoline steam or oil
"Iocomotor, "each vehicle being self
propelled through its center pair of
wheels. The power is transmitted to
these wheels from the engine of the
locomotor through differential gear
and system OF flexible couplings.
A special advantage is that the loco
motors can be made powerful but
light, requiring no extra weight for
adhesion, and the train can be run
over bridges much too weak to
sustain traction engines of the ordin-
ary type. The speeds so far tried
seem to be about four or five miles
an hour. These road trains are some
what expensive to run, but they offer
advantages in agricultural districts,
and give special promise for military
transport.
Of attempts to change the weather,
rain-making has been generally re-
garded as a delusIon, and now 1t is
proven that bomb-firlng as means of
preventing hail is quite useless.
"Hail-shootlng" had gained the con-
tidence of vine growers in the Alps to
such an extent that in 1902 the Italian
minister of agriculture appointed a
commission to make conclusive tests
of its efficacy. In the five years that
have passed since then many expert
ments have been carefully watched,
and the commission reports that
shooting the clouds had absolutely no
effect and that protection must be
sought along wholly different lines.
The tire-damp detector of M. Hardy,
Frenchman, is an ingenious applica-
tion of the microphone. Two pipes
of equal pitch one in the mine, and
the other above ground-are sounded
simultaneously, and the sound waves
impinge on microphones connected 10
series with a telephone. If both
pipes are in pure air clear note is
heard in the telephone. If the pipes
are in air of different density, beats
are heard, and these give warning of
the presence of fre-damp in the
mine.
Loss of hearing is preventable in 95
per cent of the cases, IN the opinion
of DIR. W. Sohier Bryant, who would
give as much care to the ears as to
the teeth, and would have an biologist
consulted after every cold, when any
thing unfavorable is noticed, and
regularly once a year. The most
insidious changes are of two kinds
those chiefly inflammatory and those