The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1900-05-26

A Great PHYSICISTS Pet Problem-A Bank
Vault Microphone-Marvels of Metal
lurgy-Another Harmless Match-OptIc
Observation-Disclosures Without a Bat
tery-Paper Ropes-A Notwithstanding
Mortar-Cereal Rusts.
OF two dynamical problems that have long
attracted Lord Kelvin's attention, that of the
boys spinning top has been under consideration
by him for seventy years. Mathematicians have
solved the problems Of the procession of the
equinoxes, the mutation Of the earth's axis, and
the retrogression of the nodes Of the moons
orbit. but have stumbled over or avoided the
problem of the boys top. Only Archibald Smith
has made any approach to success with this. As
every boy knows, there are three acts in the
spinning Of a top-the first the rising of the top
af2er series Of spiral motions to the second or
perpendicular or sleeping" position. and the
third the "waking" or tumbling position. The
II first act is the most difficult to explain Smith
was the first to show that it was not the retard-
ing effect Of friction on the point of the top but
the spin of the toy assisting the procession Of the
point through series of movements, that
brought the top up. and has shown further that
the rounder the point the greater is the inclina-
ton of the top In spinning to the upright posi-
ton. Lord Kelvin has been estimating the
smallest angular velocity that would cause the
top to rise. He concludes that the less the an
gular point the longer is the period of rotation,
and that five times round In q second would
sufice If the point were moving In ring with
radius Of q centimeter, or ten times in a second
II the radius were quarter of centimeter.
-
BY novel combination of telephone with
the usual electric alarm. the cause OF any dis
made out before the police are summoned. A
sensitive transmitter is placed in the vault, and
at the sound Of the alarm the person at the re-
ceiving end has only to turn a switch. sending
current through the coil of the transmitter, when
the slightest sound in or near the vault can be
distinguished.
A late experimenter claims to have proven
that cathode rays are streams Of hydrogen. On
striking target these vibrate the ether, pro-
ducing waves unlike those of light-that is Ro-
entgen rays.
The properties Of alloys, showing many anoma-
lies. are even now but little understood. Sum-
marking few striking facts. Mr.. A. E. Tucker
British metallurgist, lately pointed out in
stances of remarkable change in alloys due to
external action and internal causes, and de-
scribed an alloy Of aluminium with four per cent.
of nickel that at ordinary temperatures falls to
powder In an extraordinary manner within
few hours after being cast. Mentioning the
effect of bismuth upon copper and brass, he
stated that the influence of even trace of for
eign substance upon the properties of definite
alloy could not be foretold by any reasoning
from analogy. The wonderful metallurgical
skill of the Japanese has been reached by gener-
atoms Of Flooding, and their methods often battle
al f.,d Of
aluminium as a means of producing the rarer
metals in pure form is a process likely to re-
place the more cumbersome electric furnace in
obtaining valuable materials for alloys. An in
teresting recent alloy is a steel that does not
lose its hardness by heating during use, this be-
ing produced by melting hematite pig with steel
scrap. increasing the natural hardness by addi-
ton Of manganese-tungsten alloy, and ensuring
solidity by adding aluminium nickel.
ses
The new match of NJ. o. Lindner. of Paris, is
claimed to be free from danger and to emit no
unpleasant odor. The splints are first dipped
icto q mixture of twelve parts of chlorate of
potash, four of sulphide of anthony, three of
gum and three of powdered clay The infam-
mable compound is then applied. This consists |
of four to six parts Of chorate of potash, twelve
parts of amorphous phosphorus (the red or
harmless phosphorus), three parts of gum, and
three Of aniline. The match may be lighted by
friction on any surface.
sFs
Some curious cases of temporary but absolute
blindness from nervousness have been recorded
BY DR.. ]. Ramos, Mexican physician. The
blindness usually appeared after strong emo
ion, and gradually passed away in few days or
weeks, but one healthy young woman of tranquil
aaEnenk was suddenly attacked while
@- auitpoverv taking tlaea ia a fort