The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1909-01-23
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

6C1GNJlHlC Ml6CELLAN1.
A Mercury-Vapor Filament-Lamp- Grow
ing Range In Naval Battles-Safer Rail-
way Signals-Molding Metals by Com
preeeion--Deeert Water orks-Diet
and Work-Talking by MALTA Great
Ring Of Comet Dust Improved Welding.
The new electric lamp Of Robert Hopfelt, as
tested in Germany. is claimed to combine the
resistance to shock of the carbon lamp with the
economy of the mercury-vapor lamp. 1t has
carbon filament fused into U-shaped tube.
which contains drop of mercury and an inert
gas to transmit the heat to It, and the tube itself
is fused into bulb, giving the whole the appear
ance of an ordinary incandescent lamp. The
energy consumption per candle-power is about
60 per cent less than that of the ordinary carbon
dlament lamp. On first turning on the current.
the filament glows with about the usual con-
sumption per candle-power, but as the mercury
becomes vaporized the light increases, reaching
more than double the ordinary intensity in five
minutes. The light is pure white, without OBJ
jectionable blue or green rays.
-.
Quite revolution in naval warfare is prom
ised by the new torpedo of Engineer Lieutenant
Hardcastle of the British Navy. Thus far che
possibility Of being torpedoed at greater dis
lance than 1000 yards has not been considered,
but the range Of the new torpedo is claimed to
be 1000 yards or 1900 yards more than the latest
type In use, while its speed averages 81 knots.
Iftorpedo attacks become effective at this range,
present gunnery calculations will need to be
completely revised. Trials have demonstrated
the effectiveness of the new projectile, but It's
adoption will be delayed, as 1t is too large to fire
from the present tubes.
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Colored lights as signals on railways become
more unsatisfactory as speeds and traffic in
crease. with the growing confusion Of city lights,
and it has been suggested that system of bright
white lights in varying arrangements would be
more quickly and certainly recognized In all
weather. Three lights, for instance, might be
shown in a vertical, horizontal or slanting row,
or arranged in a triangle-each form being a
definite signal.
The flow of metals under pressure, discovered
somewhat more than 30 years ago, is the basis of
the industry of the French. Metallurgical Com
pany, which makes tubes and sections by fore
ing cold copper, aluminium, zinc, etc.. through
suitable dies. The three machines now used
have capacities of 1000. 5O0and $50 tons respec-
lively. The enormous pressure exerted by the
machines IL concentrated upon a small area,
and this causes the metal to become more or less
fluid, so that 1t can be given the desired form.
Elaborate tests of the tubes before and after
annealing, also when heated to various temper
atures, have been recently made. Among other
results it has been shown that cold drawn zinc
tubes of equal strength may be substituted for
ordinary lead pipes, and that the saving in cost
would be from rs to 40 per cent.
s's
A boat load of shipwrecked mariners havinga
few panes of glass may collect from the ocean
enough fresh water to sustain life. The great
rainless area of Chile has some brackish water,
which, however. neither man nor beast can
drink. and drinking water is now obtained by
means of a novel desert distillery containing
10000 square feet of glass. The panes are formed
into V-shaped troughs, which are placed over
shallow pans of the brackish water. The vapor
of the water evaporated by the SUMS heat is con-
densed on the lower side of the glass, and runs
down into little channels, which conduct the
fresh water to the main receptacle. Asupply of
about 1000 gallons daily is thus provided.
srs
The rational diet, as worked out by DR.. Lam
douzy, Doyen of the Paris Faculty of Medicine,
must contain the heterogeneous food necessary for
the repair of the body, and in addition still
larger proportion of fatty matter and carbohy-
drates, to maintain heat and working energy.
The dietary should be proportional to the mans
size and weight and the work required. The
common laborer should have daily 7l5 grammes
C25.2 ounces) Of carbohydrates (sugar, etc.,. 80
grammes of albumen in heterogeneous food dread,
meat, etc., and IS grammes of fatty matter. The
desk worker needs nearly as much heterogeneous
and fatty food, but only $50 grammes of carbohy-
drates.
Speaking postal cards are likely to give fresh
impetus to the decline of the letter writing art.
These are simply mailable talking machine re-
cords and their general use would make it me-
cessary to have talking machine booths at the
correspondence centers. The person wishing to
write" card would enter one Of the booths
and dictate the message to machine. The re-
cord thus made on the card is unreliable in the
usual transmission through the mail, but on be-
ing received the card is taken to another postal
booth, and machine therein reads off the words
like any photograph. These speaking postal
cards, made to Withstand considerable hard
usage. have made considerable Roadway in
France, where they were invented.
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Inc august meCeOrS, Wnlcn come from Jne Ill
rection of the constellation Perseus, are found
by w. F. Denning, the British authority on such
matters, to be scattered throughout a broad
elliptical ring that has its outer limit far be-
yond the orbit of Neptune. Every year the
earth captures many of the meteors as it passes
through the ring. So wide is the stream that
the earth. travelling IS or 10 miles second. takes
seven weeks to cross it, and the actual width.
therefore, must be nearly 100000 miles If the
crossing lie at right angles. The meteors are be-
lieved to be connected with bright comet that
appeared in 1852 and has period of about l20
years.
The novel method of electric welding of L. s..
Lachman makes it possible to use steel in place
of malleable iron for many articles. Two un-
equal sections do not weld satisfactorily, SO one
piece of metal is cast with point, and the two
projections, forced together by hydraulic
press, are made to form the highest resistance
of an electric circuit Being thus heated to
melting-point or nearly SO. the pieces, under the
great pressure, become quickly more strongly
welded together than they could be attached by
means of rivets.