The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1908-06-27
Corrssbondencs Baltimore County Union.
anTENTTFTQ MISCELLANY.

Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
Life of Atoms-Gas for Small Plants
Water Cleansed by It's Own Oxygen
Novelties from Metal Film-Ozone VEN
Observation-Disclosures ued Glass-Pictures
by Wireless Unburnable Wood-A New
Ireland.
Like worlds, animals and plants. some element
at least, as we have lately come to know. are
born, live and die. We know little of their life
periods, but A. T. Cameron points out that the
activity of radium emanation falls to one-half
in four days, to one-eighth in eight days, and 30
on, but will not completely disappear in an in
finite time The half-life period of radius active
substance, or period when half given quantity
disappears, can be determined. the time varying
from four seconds in the case of actinium ema-
nation to millions of years in the case Of urani-
UNI. Sir William Ramsey states that inhnity In
this connection may mean simply longer time
than we can measure, and that 1t is very probable
that the atoms of radium and other elements
may have definite and measurable life period.
Experiments Indicate that the radium atom has
a very regular decay, being little Influenced by
external conditions. In a given mass some
atoms are being born, some may be thousand of
years old and some may be dying, and from the
rate of disappearance we are justified In assum-
ing an average life of radioactive atom, and
that average will probably be the actual life of
an atom of that element.
Sc
The Dannert gas. the new German iiluminant
for small towns, is made from oil and coke, and
is much cheaper than water gas. which it some
what resembles. The coke used inits production
is less than third of that consumed for like
amount of coal gas. The new gas yields bright
flame, and, as there are no by-products, the pro-
cess Of manufacture is simple.
sss
In the process Of Leon Dion. partial decom-
,,auitsc,r, .rufa,,
yields oxygen and ozone that purify the water
for drinking and other uses at slight cost.
.ss
Glass mirrors for the searchlights of battle
ships are liable to break and the silvering at the
back often blisters. but the attempts to substi-
tute metal for the glass seem to have been I'M
satisfactory until the electrolytic process of
Sherrard Cowper- Coles, the British metallurgist,
overcome the difficulty of making true parabolic
mirrors of metal. BY this method a thin rehec-
ting film of silver is first deposited on convex
glass mold, then copper is deposited on the back
until this is sufficiently strengthened. Such
mirrors have come into extensive use, but an
improved type, in which alternate gold and sill
yer bands make up the rejecting surface, is now
claimed to give a more penetrating beam of
light. new application Of the CowperColes
process is to the making of metallic wall paper.
This is made in continuous rolls of copper and
contrasting metals. either with or without q
paper backing, and can be given the texture of
the finest fabrics, with beautiful colors and eff
fects. 1t is specially adapted for railway car
riages, cabins and damp walls. 1t is claimed to
be damp-proof, freproof, economical, and for
more sanitary, artistic and durable than any
other decorative paper applied to walls and
ceilings.
A new idea in ventilation seems to have given
excellent results in the Royal Theatre, at Stuff
CART, at a low cost, and without draft, or the
usual heating of fresh air supply. Within q
few minutes the air Of the entire building is
purified by means of supply of ozone. small
electromotor and a transformer convert con-
tinous current into an alternating current of the
necessary tension, and another motor and an air
blower force the air through the field of electric
discharge. where the oxygen is converted to
ozone.
Glass is made irridescent by being exposed, in
red-hot condition, to the fumes of salts of tin,
barium and strontium. Red is produced by the
strontia, blue by the baryta, and blush white
by the tin. In ancient glass. which is more
Opaque, irridescence is due to partial decay.
s~s
While the transmission of pictures by wire
has reached high degree of perfection in the
process of Prof. Korn, which depends upon the
varying electric resistance Of the selenium cell
under changing light. the sending of photo
graphs and drawings by wireless telegraphy is
in an incipient stage. In the method of H.
Knudsen, the photograph has its dark parts
brought into relief by busting the usual mega
tive with some powder. like iron filings, which
adheres only to the dense portions. The trans
hitting apparatus consists essentially of clock
-'v~rA- a.ivsa Sssriasse, wihvn movesastyle paek-
met the sf1s p as tne raIseg !.
the gap in relay circuit. The relay current
causes an induction coil to transmit an electric
wave. The receiver is similar instrument in
which the style, normally raised, is depressed
whenever the electric wave acts upon the CO.
herer, and thus closes asuitable circuit. Perfect
synchronizing is ensured by causing the wave
from the transmitter to start the carriage of the
receiver at the beginning of each new stroke.
-
Asbestos wood, which seems to be attracting
attention as a new structural material is made
chiefly from abestos fiber, and is stated to be
about two-thirds as strong as ordinary wood and
to take higher polish. 1t is as easily worked
as oak and maple, while nails hold in it better.
The material is now usually made in sheets
three or four feet in size, and is adapted for
roofing and walls, but it can be panelled for
wainscoting or doors, or nodded into ornamental
trimmings.
IA
Statistics published by the British Department
of Agriculture show that 80 per cent. of Austria
is under forest, per cent of Denmark, SD per
cent of England, 46 per cent. of Scotland but
only 1.5 per cent. of ireland. A timber industry
and other great benefits for Ireland are antici-
pated from the reforesting movement now en-
Enthusiastically under way.
CASTORIA
For Infants and Children.
The Kind You Have Always Bought
signature sssss se: Of Nzzazz~