Millheim Journal. [volume] (Millheim, Pa.) 1876-1984, 1880-02-26
Velocity of "a Rife Bullet.

Professor Spice of the Cooper Institute,
New York. recently undertook TO determine
the actual velocity of a rifle bullet fired
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
in determining this question was about 200
feet. TO carry this performance out he
had secured the cooperation of Lieutenant
+. l.. Merrlman. of the Brooklyn Thirteenth
Regiment, WHO has gained some reputation
at the CreedmoOr range. as evlnced by the
medals which he wore. In the first place,
Prof. Spice explained the apparatus TO be
used. He called the attention of the au-
dience to mahogany base, ~ inches by
L inches ou which were placed two levers
which carried bent wires TO make marks
on piece of smoked glass underneath the
points. One of these wires was connected
with a 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, the distance from the begin
ming of one line to the beginning OF the
next represented a second of time. The
second lever, exactly opposite, had a sprin5
attached to one end, which kept the point
off the glass. Ii 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
ths rrIn ha
current tending to keep it elevated. In ad-
dition TO this, the current from the stronger
magnet passed through loose wire resting
on two globules of mercury, and immedi-
ately in front Of this wire was to rest the
muzZle of the rifle. The weaker current
passed through a 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
riti9. 1t was regular Creedmoor, 45 cali
bre, 34-inch barrel, and placed in it q car
fridge, containing 430 grain ball, and 45
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
above described was then set i'll motion. On
its striking the fifth second the plate Of
smoked glass was drawn along by the de-
scent of weight on The top of column of
sand which ran out Of tube. On the sixth
second, Lieutenant Merriam Iul cd 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
a spring, when the bullet broke the second
wire, The CONSEQUENCE o. this was that
the pognt connected with the. lever scraped
q very short line on the smoked glass, while
the othdr point, being kept down during
the swing of the pendulum, scraped a longer
space. Then the glass was withdrawn aud
placed in the stereopticCn, projecting q
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 the shorter line was inches
long, and the other line feet 2 inches.
These numbers were brought down TO the
common fraction of inches, the result CIV
ing 10 inches for the longer space. 1t was
then ascertained how many times the for
mer was contained in the latter, and the
fraction thus obtained was clearly the frac-
tion of second that the bullet took TO pass
from one wire to another-that is, l-22 of
a second. Multiplying the distance be-
tween the wires (33 feet), as above, by the
denominator of the above fraction, the ve-
locity of the bullet in feet was obtained,
namely, 726 feet in a second.