The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1908-08-22
Correspondence Baltimore County linton.
SCIENTIFIC MISCELLANY.

Correspondence baltimore County linton.
SCIENTIFIC MISCELLANY.
Birds and Man-True Hot-Weather Cloth
AN Improved Ailoy-Radiograph
Snap Shots-The Diamond on Fire
Mosquito Trapping-The Kaieer's Hob
by-Horse-AH Heat Battery,
A bird population Of about 3O,75O,0OO exists in
Illinois in summer, according to the study be-
gun by Prof. s. A. Forbes, this being an average
of CAS- birds to the square mile, while the average
for the entire year appears to be 722 to the
square mile. The summer estimate is based on
a count over a strip Of IL square miles, showing
TAO birds belonging to s. species. The principal
species, in the order of abundance. were the
English sparrow, meadow lark, bronzed grackle.
mourning dove, dsckcissel, red-winged black
bird, prairie horned lark. flicker, robin and field
sparrow, and these ten species included more
than 70 per cent. of the birds seen, the English
sparrow alone representing IS per cent. The
persistence of the birds in the face of extraordi-
nary changes in environment is one of the strik-
ing impressions of this study. Aside from the
results of the introduction of the English spar
row, and the direct destruction of game birds
and birds Of prey, the main effect Of human oc-
cupation seems to have been the withdrawal OF
the praire birds from the Indian corn area to
the pastures. meadows. and fields Of small grain.
-
A fabric called ''solaro'' has been produced by
English manufactures in response to the call
for something more scientific than all-white
clothing for tropical sunshine. 1t has a red
backing interviewer with the outside cloth with
out showing through, and the face may be
white, gray. or any desired color. The red in
side arrests the actinic rays, preventing sum
stroke, stomach disorders and other effects of
intense summer heat. The material is Of fine
wool, shower-proof as well as sun-proof, is suit
able for both sexes, and has been adopted for
British officers appointed to tropical service.
-
Magnalium, the new alloy Of a Berlin syndi-'
cate claims advantages that mako IT most I'm
portant and interesting material. 1t contains
from 90 to 90 per cent. of aluminium, the remain
ing percentage being chiefly magnesium, and it
retains the good qualities of aluminium, while
having the much desired greater hardness and
greater tensile strength. with greater resistance
to oxidation than any other light metal or alloy.
It is almost unaffected by damp air, water, CASE
GUS ammonia, carbonic acid and most organic
acids. It be cast in the liquid condition, like
pure aluminium and the castings can be ma
chined, acquiring smooth, mirror like surface.
Unlike pure aluminium, it may be cut to perfect
BCfeW- tuItduS duu ulcu WlbuOub CAOeeAu8 buO
file or tearing the material. The uses found are
already quite numerous, and include kitchen
utensils, parts of spinning and milling machin-
cry, saddle skeletons, surgical appliances, and
chemical apparatus
Instantaneous photographs with x-rays have
been known for several years, but it is only re-
Gently that DIR. Graedel, of Nauheim, has made
them practicable. as a part of the physicians
everyday work. In a late London demonstra-
ton, satisfactory pictures were taken in one
fifth to one-half of second, with slight modif-
cation of the ordinary apparatus. The con-
tinuous current of 200 to $50 volts from the usual
electric supply main gives the best results, and
q large primary current-up to 90 amperes-is
used, through special triple anode electrolytic
interrupter. At so inches the parts are shown
in almost exactly natural size. with practically
no distortion, the pictures being good.
s"s
The diamond was first burned by Davy and
Faraday in 1914. It was held on a platinum rod
in glass globe of % cubic inches of pure hydro
gen and the Duke of Tuscany's burning glass
a lens of IA inches and one of 8 inches separated
6Kfeet-concentrated the suns heat. In X of
an hour the stone burst into scarlet flame. Out
of focus it blazed4 minutes, and was consumed
in two more trials.
s+s
Mosquitoes being one of the pests of tropical
countries, Maxwell LEROY, of the Indian Ento-
mological Department, has made Especial study
of their destruction, and has been particularly
successful with the novel method of trapping
them. He uses box about a foot square, which
has hinged lid. with a small aperture that can
be closed bya slide. This box has bottom of
tin, and the sides are lined with green baize.
Set in a dark corner of the room, the simple APP
paratus proves an attractive retreat for the in
sects seeking to hide from the sunlight on enter
ing the house in the morning. They soon col
lect inside, and when all have settled ateaspoon-
fAleSpbeRziRej ias aud the iselased-
troy continued setting his trap as long as the
mosquitoes were troublesome, and in a1days de-
stroyed over 300.
strange steed is the new horse of the Ger
man cavalryman. 1t is an electrically driven
exerciser, in the saddle of which the soldier may
enjoy a comfortable long short canter in the
shelter of home, aud the teetering motion is an
exact imitation of that of horse in action.
Turning a screw varies the gait as may be de-
sired. Any person may ride, and adjustment of
a. counter weight adapts the mechanism to a
light or heavy rider.
For an inexpensive thermo-electric couple
for measuring temperatures of molten metals
W. H. Bristol, an English metallurgist, has hit
upon the plan of using two varieties or grades
of carbon or graphite. With most metals these
do not alloy appreciably and they resist very
high temperatures. A couple that was particu-
larly satisfactory had pure carbon or graphite
for one element and carbon or graphite COM
bined with Is to 20 per cent. of Bavaran clay for
the other.