The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1909-07-31
Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.

Correspondence Baltimore County Union.
SCIENTIFIC MISCELLANY.
Blasting Cartridges that Explode - The
Earth as an Engine Boiler-The Worlds
Rain-Scientif1c Research in the Factory
-Lightning's Colors-Gauging the Com
plexion - Britain's Rats = Hardness
Meter
One of the serious dangers of mining is the
failure of the detonator to explode the blasting
charge. The unfired charge is then left in the
rock and, at some later time, on being struck by
a miners tool, it explodes, killing or injuring
the miner and any other persons near. A new
safety cartridge is designed to prevent such
accidents. A needle is fitted to a tube in one
end, and after the hole is rammed this needle is
withdrawn and the detonator is inserted in its
place. the charge being then fired electrically in
the usual way. When a cartridge fails to explode
it is not left in the rock. The imperfect deton-
ator is withdrawn, a new one ls inserted In its
place and the charge is then fired. Though
specially adapted for coal mining. this invention
is expected to be a valuable safeguard In general
blasting operations.
Industrial power from dormant volcanoes is
believed by an Italian engineer to be a simple
and practical matter which he expects to under
take on large scale. He has made prolonged
and careful observations of solfataras and has
found that the steam has varied but very lightly
in quantity during period of ten years or more
and has scarcely changed in temperature. The
steam rises to heights of 80 to 90 feet, the tenn
perature ranging from 2500 to sSO0 F.
F.F
The rainfall of the continent, after long col
lecting of records, has been estimated to average
so inches year. Ocean measurements are diff
cult, but, after considering all known facts,
Fritsche has now concluded that the entire
earth's surface has mean annual rainfall of 80
inches. This means total fall of 1888 million
metric tons of water every minute.
-
Modern industry depends upon science to
degree that is not easy to estimate, but a sug-
gestive hint was given in a recent address by
C. e. Skinner. of the research department of the
Westinghouse Electric and Manufacturing Com
pany. The investigation of the properties of
materials is probably the most important COM
mercial research. A large factory uses great
variety of materials, the classes employed by
the Westinghouse Company exceeding 500, and
the entire resources of physics and chemistry
are drawn upon to show what they willdo. New
tests are often devised to determine special
properties, as in the cases of metallic alament
lamps and alloy steels. Other scientific research
of Importance is that applied to developing
processes of manufacture and new compositions
for special work, studying the physical laws
aside from the properties of materals-con-
nected with designs, the testing of machines
and the examination of reputed inventions.
50
For five years tabulated record of the colors
of lightning has been kept at EPSON, England,
by Spencer c. Russell, and he has made 81 obser-
vations of forked lightning in thunderstorms
and Is observations of sheet lightning. Great
diversity in color has been shown. Red has been
commonest in forked lightning. with blue closely
following, and orange and green least frequent,
and white is seen oftenest in sheet lightning,
red aud yellow coming next. Hail usually comes
in thunderstorm with blue lightning.
~
The color of the hair, eyes and skin is meas
ured by new instrumental simplifed LOW
bond tintometer-devised by ]. Gray. The OBJ
server looks at the object under test through
tube and interposes Lovibond's standard color
glasses in front of white surface at one side of
the aperture until the glasses transmit color
exactly corresponding to that of the hair, eyes
or skin. The exact composition of the color is
then obtained from the readings on the standard
glasses.
The war against rats is being waged vigorously
in Great Britain, where the annual damage they
cause is variously estimated at amounts ranging
from ten to fifteen million pounds sterling.
Potatoes infected with a tasteless germ are
placed within reach, and this germ-harmless to
man-is expected to cause rapid decrease of
the rodents by spreading fatal disease among
them. AS further step the Society for the
Destruction of Vermin seeks to set price on
the animals heads, having offered prize of ten
guineas and diploma for the best method of
making ratskins commercially useful. Taking
the London and India Docks as an example of
the seriousness of the plague, it is stated that
each of the ~ sheds stands on an acre of ground
and is estimated to harbor 1000 rats under its
floors, making total rodent population of 1000
for these docks. Each rat is charged with dam
age of at least farthing day. giving total
yearly loss of more than ten thousand pounds.
80
A novel device for measuring the hardness of
metals is called the scleroscope, by Albert F.
Shore and DIR. Paul Herould, its inventors. A
steel ball weighing 40 grains, is enclosed in a
glass tube, and the hardness is indicated by the
rebound as the ball is dropped on the metal
under test. A scale measures the height of re-
bound. On this scale 100 is the average hardness
for carbon steel and proves to be the safety
limit for steel tools after relocating and temper
ing. The instrument is valuable in making tools
of standard hardness.
="
Lead-wool consists of pure lead cut into fine
strips by machinery and is put up in pound
skeins of yard-long threads For making tight
joints it is simply laid in the joint socket and
Dounded in with a caulkinp tool II Yields into
a solid mass, filling every interstice and it en-
sures more thorough work than results from
using molten lead.