The Baltimore County union. [volume] (Towsontown, Md.) 1865-1909, 1907-06-01
COsYssp0ndsnce Baltimore County Uns0n.
SCIENTIFIC MISCELLANY.


SCIENTIFIC MISCELLANY.
A Curious Phenomenon and It's Utilization
Big Roots Mean Small Plants-Wind-
mill Hydrauiice-The Electric Anemo-
meter-A Vest-Poclet Telescope-X-
Rays E5fects-The Long Focus Micro
scope-An Improved Level.
About eighty years ago DR.. Robert Brown dis
covered that microscopic particles-such as
powered indigo, carmine, gamboge, etc.,-keep
In rapid movement when suspended in water.
The peculiar oscillations may continue for
years. and seem to be the nearest approach to
perpetual motion yet observed. 1t lately oc-
CURED to Drs. Carl Herring and e. +. Northrup
to test the influence of an electric current upon
this Brownian movement. When the suspend
ing liquid was placed between two electrodes.
the particles took q very decided course across
the neld, some being attracted to one electrode
and some to the other. Each particle had its
Characteristic direction, and in some mixtures
the particles Of one material travelled with the
current and those Of the other against it. The
motion was so positive that DR.. Northrup has
made 1t the basis of q successful electrical
measuring instrument for special purposes.
ASs
Everybody knows that plants grow largest in
rich soil, but it Is not so well understood that
the largest roots may be found In very poor soil.
This has been made subject of late expert
ments By French botanist Lots of COLA seeds
were planted respectively in washed sand, in
soil exhausted by many crops. and in good soil;
and after seven weeks, with like watering, the
roots OF the first lot had grown IA to IS inches,
Of the second lot 10 to IL inches and of the third
lot only inches. In the poorest soils the roots
must extend farthest to get nutrition.
-
Delicate speed-regulating apparatus is re-
quired when dynamo is geared direct to a
windmill. In new system. the windmill pumps
water into hydraulic accumulation, and water
from this-kept by automatic valves at pres
sure Of 70 pounds per square inch-drives the
dynamo A storage battery saves the surplus
power in the usual way.
80
The novel and ingenious thermometer of R.
9oldschmidt, Belgian electrician, depends
upon variation In electrical resistance due to
the cooling by the wind of an electrically
platinum wire. To compensate for the chang
ing temperature Of the air itself two similar
wires are used, and these form arms of kind of
Wheatstone bridge, which is SO adjusted that
when the two wises are Of equal resistance the
galvanometer IL ct zero. After this adjustment
the cooling of the exposed wire-the other be-
ing protected-varies with the wind. The gal
vanOmeter-which may be at considerable dis
tance away-is correspondingly DETECTED, and
gives direct reading Of the winds velocity,
the indications having been accurately cali
Jbrated by driving one of the instruments on
rotating stand through calm air at series of
known speeds. With recording galvanometer
and an electrical weather-cock-the latter act
ing through changes Of contract on circular
slide wire-a permanent record can be kept Of
both the velocity and the direction of the wind.
80
A little apparatus Of great utility is the
"UniIensr telescope lately produced by London
opticians. It is simply q convex lens mounted
ia metal ring having projecting screw at one
side, the lens being 2x inches in diameter and
having focal length of feet. The instrument
serves as q very good feld-glass. In use it can
be held In the hand at arms length or screwed
to the end of stick, and at maximum efficiency
about Q feet from the eye-it magnihes four
diameters. It is especially recommended for
observing birds and plants. 1t is not intended
% an astronomical telescope. but shows stars
in the Plefades where the unaided eye usually
sees 9.
Working with x-rays Is liable to cause derma-
tits. and the President of the British Electro
Therapeutic Society has suffered for two years
from 40 or 80 warts on each hand. The pain is
constant and severe. On the other hand. Prof.
Imbert, Of Montpelier. reports that like expo
sure has restored the color of his hair and beard
which had long ago turned white, his present
appearance being very youthful.
a..
The unfamiliar living world of the little,-
wIthits activities domestic relations and TRACE
dses.-is brought into better view by the bio
scope, or longfocus microscope, of NJ De Gas
paris, Of the University of Naples. To be con-
siderably magnihed under the ordinary micro
scope. insects must be brought within fraction
OF an inch Of the lens, and with the frightful
observing apparatus 30 near their movements
must be far from normal. The new instrument
ssvery simple. It consists essentially of a tube
containing q system of achromatic detectives
and wide-feld eyepiece, with various Access
s0ries, such as camera lucida to aid in drawing.
Objects at distance of about 20 inches are mag
nifed more than twelve diameters. Ants, spi-
ders and many other insects can be watched I'M
disturbed: aquatic animals can be studied
through the glass of an aquarium or in their
natural home, and the habits, emotions, strug-
giles. living and death of these creatures can be
placed before us in an environment of strange
multi-colored plants. The observations, we are
told. are full of surprises. Materials submitted
TO high temperatures or electric charges may be
viewed. and the physician gains means of peer
ing into cavities, like the larynx, ears, etc.
~
A very sensitive direct-readlng level, called
the "Shaftometer," has been brought out by
Halifax company for lining up shafting, ma
chinery, etc. It has rigid gun-metal base 10
inches long, glass tube IL inches long, and
brass scale runs the entire length of the tube
ION each side, each graduation of about one
eighth Of an inch corresponding to difference
in level of one-thousandth of an inch per foot.
A table shows at glance the thickness of pack
ing required to bring given length of shafting
up to level.
80
In military test at Caux, on the Lake of Ge-
neva, searchlight with reflector of 3.24 feet,
has thrown its rays rs miles, showing objects
distinctly at SIS miles. A generator of "a horse
power gave light of 100000 candles, but 40
horsepower IL expected to yield 100000.
ESTABLISHED 1886.
1880