The morning call., 1894-12-09

and within this no0p. 1t would whlrl as
rapidly as in the first instance. So would
the egg.
Professor Thomson has described how
he has laid common steel file on table
underneath which a coil was fixed. and
caused metal disks to revolve in his hands
by merely holding the diks near to the file.
But even this is not as curious as a feat
performed in another laboratory not long
since. A number of metal plates were
laid out on table as though in prepare
ton for a dinner party. Then some peo-
pie were asked to seat themselves at the
table, and no sooner had they done so than
the plates suddenly began to Jump into
the air. Nothing could have been more
startling, and there was a general and in
Simultaneous stampede. Then it was dis
closed that each plate had been laid d.
rectly above where coil was placed I'M
der the table.
Following is an idea obtained from the
above. One of the persons present sug-
gested that church contribution boxes
could be made on this plan, with curious
results. Such box has been made, and
it is simply impossible to get money 10
STAY in it. Pennies especially have no
liking for ii, and fly ont In a surprising
manner.
The same principle which governed the
above was applied in another direction
during an exhibition which was given by
the Franklin Institute Of Philadelphia
some time ago. La the middle OF the hall
stood plain pine table, and on it was
handful of ordinary tenpenny nails. The
nails lay In a heap, aud it looked as
though some workman had thrown them
there. Spectators were busy watching
other things, and the nails were passed by
with glance. However, the eyes Of one
old lady and gentleman nearly popped out
of their heads when, happening to look
at the nails. the latter all got up Oh
end, heads ~, and actually bowed and
scraped to the ast0nlshed couple. The
table was surrounded in an instant by
aslOnished people, before whom the nails
paired off and danced and waltZed. Some
fell on their sides, but Immediately got UP
and bowed an apology. Coils beneath the
table did it all. The heads of the nails,
con tanning more bulk than the points, sus-
tanned more repulsive action, and conse-
Quently got farthest away from the coil,
which in its turn was regulated from an
other part of the room.
Mr. Tesla, in the course of recent lee
tnre, requested that the lights be turned
off 1t was done, and then the audience
saw truly magic sight There stood the
electrician with a small lamp in his hand
and his hand above his head. Rays of IN
eQualed beauty came from the lamp and
spread down over the body Of the man.
The lamp was simple affair and no wires
connected it with hidden source of sup
been rubbed. and beautiful jewels were
cleaning forth.
This was followed by another and even
more startling experiment. Again the
room was darkeued. The lecturer became
invisible to the expectant spectators. and
hand of fire. reached out from the dark
ness. and, all transparent, was seen wav-
ing aloft, while shooting out from it were
sparks and streams of light.
In exposition of these seeming wonders
let me give Mr.. Tesla's own words:
"When two conducting bodies are insu-
lated and electrified we say that an cleo
trostatc force is acting between them.
This force manifests itself in attractions,
repulsions and stresses in the bodies and
space or medium without. So great may
be the strain eXerted in the air that it NAV
break down, ana we observe sparks or
bundles OF light or streamerS, as they are
called. These stTeamers form abundantly
when the force through the air is rapidly
varying. l will Illustrate this action in
novel experiment, in which | will employ
an induction coil. The coil is contained in
a trough Of oil and is placed under the
table. The two ends of the secondary
of hard rubber which protrude to some
height above the table, Attached to one
wire running through the hard rubber is
large sphere of sheet brass.
L now set the coll TO work and approach
the free terminal with a metallic object
held in my hand. this simply to avoid
burns. AS | APP roach the metallic object
to distance OF eight or ten inches tor
rent of furious sparks breaks forth from
the end of the secondary wire which
passes through the rubber column. The
sparks cease when the metal in my hand
touches the wire. My arm is now tray.
ersed by a powerful electric current, vi
brating at the rate Of one million times
second. All around me the electrostatic
force makes itself felt, and the air mole
cules and particles of dust flying about are
acted upon and are hammering violently
against my body. So great is the agita-
ton of the particles that when the lights
are turned out you may see streams of
feeble light appear on some parts of my
body.
II can make these streams of light visf-
BILE to all by touching with the metallic
object one of the terminals as before, and
approaching my free hand to the brass
sphere. which is connected to the other
terminal of the coil. As the hand is ap-
preached the air between it and the sphere.
or III the Immediate neighborhood, is more
violently agitated. and you see streams of
light break forth from my finger tips and
from the whole hand"
THEODORE WATERS.
Copyright 1894, by s. S. Mcclure, limited.