Butler citizen. [volume] (Butler, Pa.) 1877-1922, 1880-02-04
VELOCITY OF A BULLET
INTERESTING EXPERIMENTS MADE BY
PROFESSOR SPICE IN NEW YORK.

INTERESTING EXPERIMENTS MADE Bl
PROFESSOR SPICE IN NEW YORK.
Professor Robert Spice, the Brook
lyn chemist and physicist, appeared
last Saturday evening at the Cooper
Institute, New York, in lecture or
projectiles. The great hall was crowded
in every part-many standing in the
aisles. When the well-known face o
Mr. Cooper appeared the audience, as
usual, gave him a very hearty wei.
come, and the applause was renewed
when, on the introduction of Professor
Raymond, the lecturer came forward.
The task which Professor Spice was
to accomplish was to determine the
actual velocity of a rife bullet fired
across the stage. The distance meas
ured on the platform was thirty-three
feet, which the lecturer explained was
shorter than usual, as the ordinary
distance used in determining this
question was about 200 feet.
To carry this performance out he
had secured the cooperation of Lieu
tenant +. l.. Merriman, OF the Brook
lyn Thirteenth Regiment, who has
gained some reputation at the Creed
moor Range, as evidence by the med
ais which he wore In the first place.
Professor SPICE explained the appa-
ratus to be used. lie called the atten-
ton Of the audience to mahogany
base, twelve inches by fifteen inches,
on which were placed two levers
which carried bent wires to make
marks on piece of smoked glass un-
derneath the points. One Of these wires
was connected with a pendulum at
tached to an Atwood machine, vibrat-
ing seconds By means of electric cur
rents the lever connected with the PEN
1ulum came down on the glass pre-
cisely at the beginning Of each second,
making series Of lines separated by
spaces somewhat similar to the old
Morse alphabet. Consequently the dis
.ance from the beginning of one line to
he beginning of the next represented
4 second Of time.
The second lever, exactly opposite,
bad spring attached to one end,
which kept the point off the glass II
llso had two electro magnets, one at
each end, which had electric currents
passed through Of different strength
he weaker current tending to pull the
ever down on the glass; the stronger
tending to keep it elevated.
In addition to this, the current from
he stronger magnet passed through a
oose wire resting on two globules OF
mercury, and Immediately in front OF
his wire was to rest the muzzle Of
he rife. The weaker current passed
through precisely similar loose wire,
IIso on two globules Of mercury, which
wire was placed thirty-three feet dis
ant from the first wire.
Lieutenant Merriman now came for
ward and loaded his rife. 1t was
egular Creedmoor, As calibre, 34-inch
,arrel, and placed in it cartridge
$50 grain ball and 45
rains Of powder, explaining that this
vas not q full charge He then took
lis position. The object was to shoot
way the wires on the mercury. A
,ox Of sand was placed to receive the
,all.
The pendulum above described was
,et in motion. On its striking the
fifth second the plate Of smoked glass
vas drawn along by the descent Of
weight on the top Of column Of sand
which ran out Of tube. On the sixth
second, Merriman pulled the trigger
md both wires vanished. On the first
wire being broken the point of the cor
lever descended on the
glass, but Immediately rose again by
he action of wire spring, when the
bullet broke the second wire. The
Of this was that the point
with this lever scraped a
very short line on the smoked glass,
while the other point, being kept down
Turing the swing Of the pendulum,
,craped longer space.
Then the glass was withdrawn and
placed in the stereopticon, projecting q
nagnified image Of the lines on the
screen. The relative lengths Of these
ines were ascertained, thus obviating
my source Of error in measuring the
minute lines on the smoked glass.
This method Of measuring the lengths
was claimed to he original by the Pro-
cssor
On this measurement it was found
hat the shorter line was 5 inches long.
md the other line 6 feet 2 inches.
These numbers were brought down to
he common fraction Of inches, the re-
suit giving 10 inches for tie longer
space. 1t was then ascertained how
many times the former was contained
m the latter, and the fraction thus OBJ
tained was clearly the fraction Of a
second that the bullet took to pass
rom one wire to the other-that is,
l.22 of second Multiplying the
distance between the wires (33 feet, }
ls above, by the denominator Of the
above fraction, the velocity Of the bull
let in feet was obtained, namely, 1876
feet in second
The result was long applauded /;
and the lecturer, to make matters sure,
determined to repeat the experiment.
The second attempt was equally sue
cessful. Prof Spice then proceeded
to give Illustrations Of experiments Of
the wclLknown magicians, showing
how science and art are rcsorted to de-
ceive the senses His performances and
explanations were Of great interest to
his hearers.