The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1906-02-10

l61i|HlS|a|lshs slSIliIsIlSlils
COrsspondmes BaItimors C0sntv Unl0n.
SCIENTIFIC MISCELLANY.
An Accurate 9un-Dial-N-Rays at Home
"A ConQuoring InBect-The Hardest
M6tal-A Medical Electric Heater-The
Telegraph Of Savages-The Best Fruit
Packing-A Useful New Material.
The sun dial Of Prof. Albert Crehore, which
waa one Of the striking novelties ct Q recent
conversazione Of the British Royal Society, is
designed 70 tell standard time with precision.
The ordinary gnomon 10 abandoned. and the
shadow Of . small bead fixed on q wire Is cast on
the interior Of true cylindrical surface, upon
which figure Of eight curves are drawn marking
standard noon for each day Of the year. The in
clination Of the cylindrical surface. whose axis
is made parallel with that Of the earth. repre-
sents the latitude Of tine place. Circles drawn
on the cylindrical surface represent days Of the
month, and these are followed by the shadow Of
the bead, the hour described In the circle being
always Of the same length, and q scale of min
utes shows the true mean time within few sec
onds.
The N-ray screen Of n. Blondlot is painted
with mixture of powdered sulphide of calci-
I'm and collodion, diluted with ether 90 Is to
form very thin paste. Small patches. few
millimeters across and very near together, are
painted With this paste on blackened cardboard,
and give the appearance Of a spotted fabric.
This screen is used for testing both luminous
end non-luminous sources Of radiation. After
exposure to sunlight. the greatest source Of
N-rays. the spots, in darkness and perfect quiet,
appear luminous though not equally 90, some
being nebulous. But on speaking or whistling,
o. bringing knife or the clenched Hst near the
cardboard, the nebula resolves itself, and all
spots appear distinct and brighter.
ss
After sitting for his portrait to two German
artists, scientific observer has calculated that
each Of the two pictures, though painted by diff
ferent methods. required 5000 strokes Of the
paint brush.
The tiny setse-fy Of Africa. 90 formidable as
destroyer Of horses and cattle, Is at last in
dicted for granddaughter. Col. David Bruce,
who has been making investigations in Uganda.
concludes that the parasite Of "sleeping sick
ness" the mysterious and fatal brain disease
that has depopulated q large area Of rich coun-
Try within ten years. has been brought from the
Congo and is spread By the tsetse-Hy. Where
the NJ does not exist there is no sleeping sick
ness. very peculiar distribution Of this dis
ease IL noticeable, is restricted to the numer
Gus Islands Of the northern Victoria Nyanza and
70 belt Of shore few miles wide, but only in
localities Of forest with high trees and luxuriant
under6rowth.
4ne success OF tantalum as q material for cleo
fric-lamp hlaments has drawn attention to the
remarkable properties of the metal. and may
lead to many demands IL the supply can be sum-
GENTLY increased. Chief of these properties, as
DR.. Mollwo Perkin points out, is extreme due
tility combined with extraordinary hardness.
diamond drill, rotating 5000 times minute
Tor three days and three nights, penetrated only
aquarter through sheet Of tantalum one twen-
ty-nfth OF an inch thick. and the diamond was
much worn. This hardness suggests the use of
the metal for drills in place Of the diamond.
-.
new apparatus applies electric heat to the
inner ear. One end of an ''otoscope" is inserted
In the external ear, the other end remaining
open for viewing the interior surface, and the
tfrom an electric coil IN this is blown through
into the ear by hand bulb or otherwise.
sss
The problem OF overcoming the roll of ship
Ct sea has bafEied many inventors, but the plan
ola London dentist named whItehouse is claim
ed to have proven successful. His berth swings
on four cords, which by electric motors are
automatically operated to counterfeit the motion
Of the boat.
The curious wireless telegraphy Of the Basu-
toe, lately described By Rev. A. Rideout, q mis-
sionary. seems to be q sample of methods long
10 use for rapidly spreading news among saw
ages. The apparatus used by this particular
tribe ts kind Of drum. consisting of O gourd
with head Of dried kid-skin, and the sounds
from this are heard at distances of 1--WE to eight
miles. Messages are sent by a secret code Of
drum-heats. serving the same purpose as the
Morse alphabet. special corps Of signallers is
always on duty. and when message is sounded
It Is promptly received and pass on to the de-
sired village, when 1t is delivered to the proper
person. This system is used for distances of at
least thousand miles. Messages forwarded to
missionaries were unfailingly and accurately de-
nvered, and the events of the Boer War were
made known to the missionaries by gourd line
hours before they received the news by field
telegraph.
In tests in France and Spain cork has proven
10 be the best material for packing fruits and
vegetables. 1t is used in alternate layers with
the fruit, the outside layers being always of
cork, and the interstices being carefully filed.
About 20 pounds of cork will serve for 400 or 500
pounds Of fruit. The material protects against
cold. heat and humidity. and fruit that Is sound
at first and well!packed may be kept fresh for
year.
&c
RCalxia. new substitute for terracotta and
plaster, is mixture Of 45 parts Of calcined gyp-
sum, % OF water, 10 Of albumen. Q of alum. 4 Of
euluhnte of maRneaia and NJ horav IT, a.
stronger and lighter than terracotta or plaster.
-
In two cases Of Q ronic and apparently hope
less neuralgia, relief has been reported by about
twenty applications OF violet light to the parts
Of the body affected.
miscellaneous.