The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1903-03-14

nsneut of Color Sense-Acetylene
EcK-Inoandes Lamp Pyrometry
- Travelling Lake-Velocity of Light
Marine English Improvement-AnU I'm
solved Problem Still.
Our senses, it appears, have developed through
gradual evolution. Natives OF remote Pacific
Islands are still unable to distinguish between
blue and black and DR.. +. w. Edridge Green,
whose investigations have covered many years,
concludes that the color sense1which Is distinct
is one of mans recent requirements. Primitive
man could not distinguish colors at all. Red
and violet, the colors of greatest differences in
wave-ength, were learned first. all Others APP
pearing grey then green was detected IN the
grey field, followed by yellow, and finally by
blindness that now exists, only three colors-
such as red, green and violet-are distinguished,
yellow being mentioned as red-green
BY the Hubou process, black pigment is made
by pumping acetylene into steel cylinders to
pressure of about two atmospheres, and then
passing an electric spark through the vessels,
the gas being thus associated into its carbon
and hydrogen. The hydrogen is collected for
market. Acetylene black is free from the oily
Impurities of ordinary lampblack. and the de-
mand is already so great that the first factory
now running In Switzerland-is likely to be fol-
lowed by others in other countries.
High temperatures are now easily measured
with the electric incandescent lamp. The lamp,
in line with the furnace backing or other hot
u
when the 1lament disappears on reaching the
temperature of the background. An ammeter
shows the amount of current feeding the lamp,
while a special scale indicates very accurately
the corresponding temperature up to $500 F.
The chief cause of the hostility of different
colonies of ants is found to be difference of odor
and of ages.
One of the strange features of Central Asia,
as shown by DR.. Sven Hedin, is the travelling of
the ancient lake of Lop.nor, which seems to
form an oScillating pendulum of the Karin
river. and to pass north and south across the
desert in period of LOCO years or more. The
lake of a-koshum, however, is gradually
disappearing in the place where Prjevalsky
found it, and slowly creeping northward, with
the prospect that it will occupy the ancient site
at no distant time. As the lake becomes filled
with mud, sand and decaying vegetation, the
desert to the northward is deepened by wind
erosion. 1t is already known that in the year
northern part of the desert, and there are
reasons for believing that when this point is
again reached, the course of travel will turn
toward the south. The vegetation, the desert
animals, and the native fishers, with their reed
huts, follow after the lake.
An attempt to fix the velocity Of light with
greater accuracy, using the toothed-wheel
method of Fizeau under improved conditions,
has been described by M. Perrotin. In previous
experiments, the beam of light was made to
travel distance of IL kilometers and back, but
in the recent trials it was reflected from mir
ror placed at distance of AZ kilometres from
Nm Been TO Be EffometIres pefn sac
ond, with a probable error less than 80 kilo-
metres.
Roller bearings for marine engines, Dr. p. NJ.
Tasker suggests, should increase the revolutions
from to 10 per cent. or more. Ball bearings,
while even further lessening fiction, have dis
advantages for heavy work, and are not to be
considered for any but the smaller engines of
launches.
The true fishes are estimated by Drs. Jordan
and Evermann to number 1900 species, belong
ing to 200 families; OF these $500 species have
been distinguished in the waters of North and
South America.
Guesses at the worlds age differ widely. Sir
Edward Fry points out that the physicist, reas-
oning from the dissipation of the earthS heat,
: the contraction of the sun, and the action of
thettdes, finds that the earth consolidated at a
time nearer 20 than 40 million years ago. while
the geologist, from the present rate at which
sand, chalk etc., are being deposited by river
and sea, infers that 400 million years must have
elapsed since life began on the globe. The BIZ
since the beginning of life, on the assumption
that species have multiplied by very slow varia-
tiOn, the estimate being 2, 100 million years. Sir
Edward contends that the single phenomenon
of "pelorism,n a sudden transmissible variation
among plants, sufficiently shows that the bio
abnormal development was first observed more
than $50 years ago in the yellow tOad-fiax of a
Baltic island, and has since been traced by one
observer in ITO varieties of plants.
-
A curious theory is being Investigated by the
Paris Academy of Sciences. Human stature is
supposed to be controlled by the gland in the
throat under the larynx, and artificial stimula-
ton of this gland is claimed to cause any child
to grow to maximum height.