The news and herald. (Winnsboro, S.C.) 1877-1900, 1880-02-24
Velocity of q Itttle Bullet.

Professor Spice of the Cooper Institute,
New York recently undertook to determine
the actual velocity of a rifle bullet fred
across the stage Of that hall The distance
measured on the platform was 33 feet,
which. the lecturer explained, was shorter
than usual, as the ordinary distance used
i'll determining this question was about 200
feet TO carry this performance out he
had secured the cooperation of Lieutenant
E. l.. Mcr~ >en. ofthe Brooklyn Thirteenth
Regiment WI has gained some reputation
at the Crec'r DOR range. as evinccd by the
medals VIII II he wore. In tho first place,
Prof. Spice explained the apparatus to bc
used. lie called the attention Of the au-
diencc to u mahogany base, 10 inches by
IL inches, ou which were placed two lovers
which carried bent wires to make marks
On piece of smoked glass underneath the
points. One of these wires was connected
with pendulum attached to an Atwood
machine, vibrating seconds BY means of
electric currents the lever connected with
the pendulum came down on the glass pre-
cisely at the beginning Of each second,
marking series OF lines separated by spaces
somewhat similar to the old Morse alphabet.
Consequently, tho distance from the begin.
ming of ono line to the beginning of the
next represented n second of time. The
second lever, exactly opposite, had spring
attached to one end, which kept the point
off the glass 1t had also two electro mag
NETS, one at each end, which had electric
currents of different strength passing
through, the weaker current tending TO pull
the lever down on the glass; the stronger
current tending to keep it elevated. In ad-
dition to this, the current from the stronger
magnet passed through a loose wire resting
on TWO glooules OF mercury, and immedi-
atcly In front or this wire was to rest tho
muzzlc of the rifle. The weaker current
passed through precisely similar loose
wire, also on two globulcs of mercury,
which wire was placed thirty-three feet
distant from the first wire. Lieutenant
Merriam now came forward and loaded the
rit1o. 1t was a regular Creetlmoor, As cali
bre, 34-inch barrel, and placed in it car
fridge, containing 43O grain ball, and 10
grains of powder, explaining that this was
not full charge. He then took his posi-
ton. The object was to shoot away the
wires on the mercury. A box of sand was
placed 10 receive the ball. The pendulum
above described was then set in motion. On
its striking the fifth second the plate of
smoked glass was drawn along by the dc.
scent of weight on the top of a column of
sand which ran out of tube On the sixth
second, Lieutenant Merriam pulled the
trigger and both wires vanished. On the
first wire being broken, the point of the
corresponding lever descended on the glass,
but Immediately rose again by the action of
spring, when the bullet broke the second
wire. The CONSEQUENCE OF this was that
the point connected with the lever scraped
very short line on the smoked glass, while
the othdr point, being kept down during
the swing of the pendulum, scraped q longer
space. Then the glass was withdrawn and
placed in the stcreopticcn, projecting a
magnified image of the lines on the screen.
The relative lengths of these lines were as
certained, thus obviating any source of
error IN measuring the minute lines on the
smoked glass This method of measuring
the lengths was claimed to be original by
the professor. On this measurement it was
found that tho shorter line wassb inches
long, and tho other hnc feet Q inches
These numbers were brought down to the
common fraction of inches, tho result Civ
ing 10 inches for the longer space. 1t was
then ascertaincd how many times the for
mer was contained in the latter, and the
fraction thus obtained was clearly the frac-
tion of II second that the bullet took to pass
from ono wire to another--that is, 1-22 of
a second. Multiplying the distance be-
tween the wires (33 fcet), rs above, by the
dcnominator Of the above fraction, the ve-
locity of the bullet in feet was obtained,
namely, 726 feet in second.