Omaha daily bee., 1910-02-07
Some Things You Want to Know
Delicate Scientific instruments.

Mankind owes a great debt TO the men
whose ingenuity has produced instruments
which permit the scientist TO go far be
yond the ordinary range of his senses.
Through the modern telescope the scien-
fist looks far into space and beholds mil
lions of suns outshining our own. objects
Of such immensely that our minds cannot
grasp them, and Of such distance that the
unaided eye cannot see them. Through
the microscope he discovers billions of little
creatures of whose existence he was un-
aware. With his measuring instruments
the scientist is able to measure distance
and quantity a million times more accu-
rately than with the eye; heat a thou
sand times more accurately than with the
sense Of feeling; and time a thousand times
more accurately than with the unaided
mind.
The bolometer, devised by the late Prof.
Langley to measure the heat OF the stars,
is a marvellous instrument. TIL heat of
the average star is no greater to us thWn
the heat of a candle placed three miles
away. yet this delicate instrument will
measure the varying degrees of heat givn
off by different stars. A spiders web,
a thread Of spun glass, the gauze Of a
fly's wing and a mirror as small as a pin
head, are some of the things that enter
into its construction. It is so sensitive to
heat that the image Of a mans face
thrown upon it at a distance of a half
mile will be registered sharply.
The dividing engine. used by scientists
to make spectroscope g~ratings for analyz-
ing rays of light. is perhaps the next most
delicate machine man has contrived. The
Rowland dividing engine will rule 10000
parallel lines on a single inch Of surface.
Another will draw fourteen lines on the
edge Of the finest tissue paper. 1t was
almost an lnsuperable task to get the
wheels perfect enough to do the work, but
a little electroplating brush of the most
ingenious construction finally served the
purpose. When the machine is in opera
ton 1t must be let alone, as even the prox-
unity Of a human being win Interfere with
the trueness of it's lines. 1t goes on inces-
sanity drawing its diamond point across
the hardened steel, and when the grating
is finished it sells for as much as $50 per
square inch.
Another very perfect machine is the
Whiteworth measuring machine. which will
determine thickness down to the milllonth
part OF an inch. When one desires such a
degree of accuracy it is an easy matter to
Ia hiaClluO a Sldue lOO liBHl. 10 over
come this the inventor placed a pair of
''feelers'' on it, enabling the operator to
tell when it is exactly right. The ma
chine is so accurate hat IL a man places
his finger hail against a bar of iron thirty
six inches long, 1t will register the ex-
pansion caused by the communicated heat.
The Shaw measuring machine will de-
termine length Town to the hundred-miI-
lionth part Of an inch. AS the series Of
wheels on a watch multiply the motion of
a single turn of the handspring into
thousands of revolutions by the balance
wheel, so there is a series OF little levers
in the Shaw machine which reduce the
movement Of an inch on the lever operated
by the hand to the Observation-Disclosures
part OF an inch on the one at the other
end of the series. One we'll may wonder
how such an instrument can be turned TO
human use, yet 1t was this machine which
discovered that the vibration of the
diaphragm In a telephone receiver, in regis
tering the faintest audible sound, moves
through the one-fifty-millionth part of an
inch. This machine is so delicate that un-
aided human perception cannot interpret
It's registrations, therefore a small micro
phonic telephone has been attached TO II
for this purpose. These measuring ma
chimes were used to determine the length
OF the tuberculosis germ
One Of the greatest aids to human
knowledge is the spectroscope. In its
simplest form this instrument is a fri
angular prism through which the sun
shines, revealing the colors of the rainbow.
In its complex form It takes the shape of
a telescope broken in two. with the two
parts placed at about the, angle of the two
marks of the letter V, except that they
do not join at the apex. Instead there are
a number of prisms placed between them.
which bend the ray of light going into one
barrel until the eye can behold it while
looking in the corresponding end of the
other barrel.
The powers of this instrument seem al
most miraculous. 1t will discover the pres
ence of one-eighteen-millionth of n grain
OF sodium, while the human taste can
perceive only the presence of one part of
salt In a few hundred parts of water. II
can take the thousandth part Of a grain of
dried human blood, which has been ex-
posed to the air for fifty years. and shou,