Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1908-05-20
THE GOLF BALL.
How Gravity Is Fooled In Its Flight
Through the Air.

Through the Air.
Professor Petrie Guthrie TAFT had lit
tie skill at golf, but a vast deal at sci
ence. Among the many problems to
which he applied his genius We're some
concerning that apparently simple
thing, the flight of golf ball. And
here he found difficulties SO battling
that, though he worked over them for
years and called on other scientists for
assistance, many mysteries still re-
NAMED One question that he solved,
however. is of curious interest.
The force of gravity is the one force
we know as most constant and inevita-
BILE. To defeat gravity is almost to
suspend one of natures laws. In his
Investigations Professor TAFT suddenly
became aware that gravity was de-
feated by the golf ball. The fact adj
mitted no doubt On timing the fight
of the ball he discovered that it re-
manned in the air almost twice as long
as it should have under the influence Of
gravity. Thus, with gravity acting as
usual on other things. drive of 200
yards would be completed in three
and half seconds. A thrown ball.
for example, describing the same ira
jectory. would remain in the air only
that length of time. The golf ball in
passing over that 200 yards foated Sc
renely through the air for six and a
half seconds.
1t was clear. then, that in some man.
ner the gravity was thwarted. Pro-
lessor TAFT attacked the problem of
the means. and in the end he solved it.
After searching long he found the
cause of the prolonged fight in the 70.
tation given to the ball by the clubs
impact. The secret lay In the manner
Of the stroke from the tee.
The first principle of the explanation
is in the simple fact that an object
poised in the air has an equal atmos
pheric pressure on it at all points. The
second principle is that when a sphere
rotates in a current Of air the side Of
| the sphere which is advancing to meet
the current is subjected to greater
pressure than is that side which Il
moving in the direction Of the current
To illustrate, when the golfer slices his
ball it is made to spin in such fashion
that Its front side is constantly in
movement to the right. Therefore the
pressure of the air is greater on the
left side than on the right, and the bal
curves to the right. When the ball Is
pulled, the operation is reversed, and
the fight bends away to the left. So il
the ball is topped the spinning direc.
ton Of the front is downward. Thus the
| pull Of gravity is aided and the flight
| is swiftly checked. But every properly
driven ball receives an undercut. By
the underspin thus impaired the from
side of the ball Is made to spin up
ward; the added pressure is from be
low and is in consequence directly op
posed to gravity. The result is a flight
sustained, but little less than twice as
long as It would be without this under
spin. Moreover, Professor TAFT demon
strated that without this undercut
when driving the ball would trave
only about half its usual distance.
The ordinary golfer is quite unaware
that he gives any underspin to his hes
drives, but he does. Without the un
dercut his driving would be a continu
GUS failure Chicago Record Herald.