The Helena independent. [volume] (Helena, Mont.) 1875-1943, 1893-11-26
OOMERANG
Cow They Are Thrown and the Mechan-
ical Theory of Their Flight.

Wv" 1hCy 0io wi" AK
ical Theory of Their Flight.
There are two kinds of boomerangs-one
Of which is commonly called the come
back boomerang" from the strange pecu-
liarity of its flight, while the other is called
~'barngect." The latter is used in war and
in the chase, and is about 2 feet 8 inches in
length and weighs about - ounces. 1t is
slightly curved and resembles a scimeter in
shape. The ''barngect" or war boomerang
is pointed on both ends, and is thrown to
kill or wound large game, such as the kan
CARGO and the Australian wild dog and hu-
man foes. 1t is not made to return to the
thrower. The Apache Indians of Arizona
employ a similar weapon in hunting rab-
bits. Its form varies from that of a caval-
ry saber to an obtuse angle of 100 degrees.
1t is about 90 inches long, 2 inches broad
and Thin at the edge.
1t is rather difficult to explain the me-
chanical theory of the flight of the boom
erang. First-The rotation of the instru-
ment about its free axis through the CEN
ter of gravity is the fundamental condition
of success. The faster the rotation the
longer the boomerang floats in the air.
Second-The mutation of the axis of rota-
ton has to be considered. This mutation
, decreases with the angels Of inclination Of
the JWO WlIlHS ol tlS ppOLtSEdilS, ellu III
creases with the increase of the said angle.
In the case of a small angle the plane OF
rotation keeps parallel to the initial posi-
. ton of this plane, or very nearly SO. The
two wings form one plane with their lower
sides (this angle being zerol The instrument
has no perceptible mutation, and must be
thrown perpendicularly to the vertical
plane passing through the hand. The in
then rises and returns nearly to
the same plane that it went up. This
throw is rather dSeicult.
In the second caE, the angle OF inclina-
ton of the two wings being very large, the
plane of rotation Is constantly changing in
regard to ihs inclination with the horizon,
and BY this.circumstance causes the instru-
ment to describe a series of complicated
curves like those of u large bird Of prey
before it settles at the feet of the thrower
In general the initial plane of rotation
must form an acute angle with the horizon.
which may increase to n right angle when
the inclination Of the two wings is nearing
its maximum.
Professor Egcers has formulated the fol-
lowing directions for throwing the boomer
ang: TAX the boomerang with the full
fist by one end 50 that the fiat side OF the
instrument faces the ground, and then fling
it away with o~utstIetched arm, giving ii at
the same time a rotary motion by u jerk
! with the wrist. In the moment of leaving
the hand the boomerang should have an in
clination toward the left, aud it's progress
! sive motion should he In an upward direc-
tion under . certain angle of elevation.
The angle Of inclination to the left and the
angle Of elevation vary from ons instru-
ment b another aud have to DO ascertained
by some gentle trial throws for any par
ocular instrument before the throwsr ap.
plies the full power Of his arm. The field
for practice should be soft ground, free of
stones or other hard objects. Throw it
against the wind or half against It,. Do not
practice when u lard wind is blowing."-
New York Telegram.