Charlevoix county herald., 1913-12-06
A FREAK OF
FALLING BODIES.

deep vertical Shafts OF the Copper
Country, probably not one piece CT il
would ever reach the bottom, and a per-
son could therefore stand in TIE bottom
OF one Of these shafts with entire safety
while ore was poured in at the top.
The marvel Of this is not one Of myst-
cries of caverns or deep holes in the
ground, but instead only one OF those
simple phenomena that prove that al
tho most of us have heard that the
earth is round like a ball and rotates
on its axis from west to east, few of US
actually realize it,
Within a radius OF a mile, at Calumet
Mich, are the three deepest shafts in
the world, one of them being 28 #.
over a mile deep. Nowhere else in the
world is there so splendid chance to
try experiments with falling bodies.
Accordingly the physics department Of
the Michigan College of Mines has
availed itself of the opportunity to
work out a few of the ''freaks of
nuture". One of the experiments con-
sisted in dropping smooth metal ball
two inches in diameter from the center
of the shaft and trying to catch it in a
box of clay set in the shaft 1900 IT.
down. Another ball was let loose from
the southwest corner of the shaft. The
balls were dropped by burning the
thread by which they were suspended
SO that in starting to fall they would
have no sidewise motion. The shaft is
9 by 80 IT. in cross section, and the
first of the balls was suspended four
feet from the side of the shaft, and the
second at point nine feet from the
opposite corner. Neither of them ever
reached the box of clay, one of them
was never found, and the other one,
presumably the one started from the
center, was later found by workman
lodged in the timbers on the east side
of the shaft 800 #. from surface. What
ever bodies were dropped into the
shaft invariably lodged somewhere in
the east wall.
This happens simply because the
earth is rotating on its axis from west
to east. At Calumet particle on the
surface is moving to the east at the
rate of about thousand feet second;
but particle 5000 feet down the shaft
ust keeping even with the particle on
the surface, is moving eastward at
rate which is four inches less than the
thousand feet. The ball suspended at
the top of the shaft had the thousand
feet-a-second velocity; it was not only
moving eastward at that rate when it
started to fall, but continued moving
eastward at that rate all the way down
the shaft. Meanwhile it dropped to the
bottom of the shaft at a rate which
would have made it take ia seconds
for the fall, if there had been no re-
sistance of the air to encounter. During
this IT. seconds, the particle at the
surface, and the ball falling at the same
rate, travelled III times inches, or
nearly 6 it., farther eastward than the
particle at the bottom of the shaft. The
ball started from the center of the shaft
therefore struck the east wall of the
shaft long before it reached bottom. AS
a matter fact the resistance of the air,
at the high speed the ball acquired soon
after startiug, was sufficient to prevent
any further accelleration, and conse-
quently the ball was much longer than
Ia seconds in falling. In fact, only
5000 #. of fall was required for the ball
to make the four feet from the center
of the shaft to the east wall, and the
other ball must have lodged at some
point not much farther down.
Now if the walls of the shaft were
smooth and free from obstructions, no
doubt falling body would rebound
from side to side of the shaft and final
ly reach the bottom; but the many tim
bers in the lining of the shaft, and the
levels all the way down, furnish places
where body is sure to lodge, and so if
load of ore were to be spilled into the
shaft near the top, most of it, at least,
would later be found clinging to the
east wall or stranded on the levels east
of the shaft.