Chicago eagle. [volume] (Chicago, Ill.) 1889-19??, 1895-02-02
A BIG MAGNET.
WONDERFUL INVENTION OF AN
ARMY ENGINEER.

u VIII Ooe0nDo Shop'o Compass %
. Distance o. s,x Miles. Would
Prove Of Great Service In War.
There Is q big twelve.inch gun
standing on top OF the ramparts ut
Willets Point, N. Y. 1t Is an in.
nocent-looking gun, and a big coil OF
telegraph cable wound around the
muzzle end Of the piece suggests that
IL has become fractured and that the
Government is experimenting with
an economical method Of repairing
broken-down ordnance.
The gun, however. Is the most
powerful electro.magnet in the world,
excepting those of natures own con.
struction ut the imaginary points Of
the earth known as the magnet poles.
The big magnet Is the invention Of
Colonel w. X. King, commander Of
the engineer corps Of the army sta.
toned here, and some very interest
ing experiments have been made
with IL. When Colonel King con.
ceived the idea OF building an i'm.
mense electromagnetic, he had no
thought OF its possibilities There
entered into the construction of the
first magnet two hugo guns, some
pieces Of iron, and good many miles
Of heavy insulated telegraph wire.
The guns stood on carriages on top
Of the fort. The pieces Of iron were
fastened across the breeches Of the
cannon, and were held in place by
chains. forming a horseshoe. The
telegraph wire was wound around the
muzzle ends Of the guns, making two
immense spoOls. The current Of
| electricity was supplied by a dyna-
mo, and the first time the magnet
was charged 1t developed marvellous
power.
The work undertaken simply as an
experiment soon became matter ci
great Importance. The magnet had
not beon long In existence when 1t
was discovered that 1t would derange
Q vessels compass ut distance OF
six miles from tho fort. This dis.
covery suggested that II in time OF
war an enemy's ships attempted to
pass the fort under cover Of darkness
or during the prevalence OF a heavy
fog, when the pilots would have to
depend solely upon the ships com.
pass, the commanders OF the war
ships would probably find their YES.
sells ashore near Willet's Point, where
they could be blown up with torpe.
does or destroyed by the guns OF the
fort.
Many experiments have been made
from time TO time 10 testing the
power OF the big magnet. One OF
the most interesting ever attempted
was made under the personal super.
vision Of Colonel King. A number
Of pieces of railroad iron were placed
near the muzzles OF the guns, and the
current OF electricity turned on.
Immediately the rails flew to the
magnet, and were held rs fast as II
they had been welded to its immense
core. Colonel King then had one
end OF largo chain fastened around
the pieces Of iron to ascertain tho
amount OF power necessary to pull
them away from the magnet. The
other end OF the chain was attached
to q capstan, that was held firmly In
place by long stakes driven into the
ground.
When everything was In readiness
for the test the capstan bars were
manned by eight stulwart engineers,
and they endeavorcd to pull the rail
road iron away from the magnetized
guns. After straining for some time,
the stakes holding the capstan In
place gave way and 1t toppled over.
The railroad iron had not even moved
on the face OF the magnet. The dy.
namometer which had been attached
to indicate tho amount Of strain the
magnet would stand showed that II
had resisted 90, 500 pounds. 1t was
found impossible to disturb the
pieces OF railroad iron until the elec-
tricity had been shut of.
Some time ago G lionel King caused
to be made tho one.gun magnet.
Thirteen miles Of half-inch insulated
telegraph cable was used In making
the coil on the gun. Tests with this
magnet showed that 1t possessed
almost rs much power Us the first
one, where two guns were used for
the core. A number OF exhibitions
OF the working OF this olectro-mag.
net were given before members OF the
American Society for the Advance.
ment OF Science. One OF the exhibi'
tions attracted great deal OF atten.
ton, as 1t best illustrated the power
the magnet possessed.
The test consisted OF four cannon
balls being suspended from the
muzzlc OF the gun. The balls weighed,
en- an average, 1870 pounds each.
The first one was placed under tbs
nuzzle OF the gun, and, notwith.
standing the smallness OF the point
Of contact, made so by the shape OF
the suspended object, the ball wa
held very firmly. A second cannon
ball was placed under the first one
then third was put under tho
second and when the fourth ball was
held up by the magnetic attraction
EXPLANATIONS OF surprise came from
the spectators. The smallncss of the
central point of bearing Of each
cannon ball, and the rigid manner IL
which the four iron spheres were
held up, was considered to be the
best exhibition Of the magnets
power.
During n recent series Of expert,
ments an iron tray, heaped up with
old horseshoes, big iron spikes, nuts,
1 L. A