Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-11-20

not affected by moisture or temperature
neither expanding nor contracting undel
any condition.
Specimens were obtained from China
because it was imagined that the larg,
spiders of that country would perhaps pro
duce a particularly excellent quality O
. web. However, it was found that the best
web is spun by spiders of the United States
such as are plentiful in the neighborhooi
OF Washington. Accordingly, expeditions
are made early in June each year. to get
from the fences and barns hereabout the
cocoons of the big 'turtle-back" spiders
Each cocoon is composed of a single silkeu
hlament wound round and round, though
there are apt to be some breaks in it where
Mistress Spider left off work for time.
Sending Out the Time.
The fve-foot time ball to be dropped at
the Worlds Fair will be made of canvas
on steel frame. 1t will be wound up each
day to the height from which it is to fall,
and it will be set and electrically connected
in such manner that the breaking of the
circuit at II noon will release it. The
cable by which it will be controlled has
already been laid connecting the new OBJ
servstory with the entire Western Union
telegraph system. Within 80 days it will
be in operation, the touch of button at
transmitting notice of the hour over
$50, 900 miles of wire. When that button
speaks the whole country will listen and
the hands of 70, 900 electric clocks an over
the United States will point to the correct
minute and second. There are 1000 such
clocks in New York City alone. All rail-
ways, factories and industries of every kind
pay attention to this signal. Three minutes
before noon each day all the Western Union
lines are cleared of business, every operator
takes his finger from the KEY, circuits are
opened, and, at the instant when the sun
| passes over the seventy-tifth meridian, the
spark of intelligence is flashed to all parts
| of the country. 1t requires less than one
| fifth of a second to reach San Francisco.
The II o'clock signal sent from Washing
ton indicates II A. M. for Chicago, 10 A. NJ.
for Omaha, and 9 A. NJ. for the Pacific
coast, the United States being divided into
four perpendicular strips, and each strip
setting its clocks by the time oil the rneri-
dian which bisects it from north to south.
Thus each strip is always one hour later
than the next strip to the east. The West
ern Union Company earns about 81, 100000
annually from its electric clock SERVICE
charging SIS year for setting each clock at
noon daily. The time sold thus probably
it gets from the Government tor nothing,
but anybody can have t same privilege
free of charge by putting an instrument and
wire into the observatory.
The Most Complete Collection.
The most complete existing collection of
portable instruments used in connection
with navigation is kept at the Naval OBJ
servatorv for supplying the ships. of the
United States navy. 1t includes the finest
and most costly devices of this description,
from small telescopes in leather cases to the
contrivance newly invented by an officer in
the service for determining the pitch OF a
ship in storm. There are small astronom-
ical outfits, with which one may 60 ashore
and set up miniature observatory at brief
notice. All naval vessels that go to sea
must have their chronometers regulated |
and tested at intervals.
For this purpose meat refrigerator has |
been put into the new building by Chi
cago firm. The chronometers will be placed |
in this cooling apparatus, which is of the
latest and most improved pattern, the
being reduced BY ice overhead
to 400 Fahrenheit The ice being removed, |
the air inside the box will be raised to $50
by hot.water pipes surrounding it. A
chronometer which endures such extremes
of heat and cold without being affected will
be expected to withstand similar influences
on trip from the Equator to the Arctic
Each ship is provided with four chron-
ometers and watch, the last being carried
in the pocket of the navigating officer CON-.
monty. These watches are regularly tessed
like the chronometers. They are of Amer
ican make. To such d point of excellence
has the manufacture of watches in this
country attained that time-pieces of this
kind, costing SIG or S1S. are found to run
within 15 seconds month of absolute ac-
curacy. Foreign watches are not in it with
them at all
A Style of Educational Show.
Astronomical science is now finding q
on the stage in the shape of
what are called scientific spectacles, " or
"Urania" entertainments. The lecturer on
extra mundane matters carries the sun,
moon and stars around with him from city
grand opera company is ordinarily equipped
with. This style OF educational show was
originated in Berlin, and it has been intro
duced on larger scale in this country by
Garrett P. Serviss, the well known astrono-
mer. Instead of merely throwing magic
lantern pictures upon screen, scenes on !
the moon and other planets are actually ex-
hibited BY elaborate stage settings assisted
by the finest kind of scene painting and
most ingenious mechanical contrivances
For instance, views on the moon place
the audience seemingly on the very surface
of that orb, from which the spectator looks
off and beholds the earth and other worlds
shining at brightest midday in a sky of
inky blackness. This is because the moon
has no atmosphere, the bright blue OF the
heavens as seen from the earth being due to
its surrounding envelope of air. Eclipses
of the sun and moon, as we'll as ma Y other
phenomena of nature, are shown. Aston
ishingly realistic effects of light, such
as sunrises and sunsets, are produced
by means Of rows of electrc-light
bulbs above and below the stage.
Some of the bulbs are red, some blue,
and some white, and all are controlled by
single instrument in such a manner that a
lunar or other landscape can be illuminated
by ever so many changing hues. The sun
is an arc light of $4,000 candle-power, in
closed in an iron box and projected through
lenses upon the back ''drop" from behind
The latter An eclipse is made by passing
an Opaque disc across the lens For the
moon an arc light of only 1000 candle
power is employed. Many other phenomena
ire illustrated by various devices.
Volcanoes seem to throw up streams of
lava while steam ascends in clouds from q
perforated pipe running across the front of
The stage; lightning flashes vividly, and the
scene is rendered more realistically appall-
ing by peals and crashes of thunder, which
small boy creates by banging sheepskin
stretched on a wooden frame with balls of
wood hanging against it so as to vbrate
With aweseme noise. RENE BACHE.
A MAINE FOX STORY.
How a Young Pet Learned Some Tricks