Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1908-05-14
WATCHING THE EARTH SPIN
The OLD Experiment Tried Again with
improvements.
(r'rom The Pathfndor)


improvements
From The Pathfnd"ro
You Lave been taught that the earth
rotatcs. but do you actually know that
il does? Have you ever seen any
phenomena that proved to you the fact?
We So, the waxing and waning of the
day. and say that It is caused by the
turning of the earth on it's axis: but We
don't see any more Of this than the
ancicnts did; and they thought that the
sun actually did rise and set. Well of
course. it is idle IN this enlightened day
to raise any question as TO the rotation
Of tho earth; the fact is established
b, yond peradventure: but any device
by means of which this rotation is ac-
tually made visible is certainly Interest,"
Ing and to watch the process causes a
feeling akin To awe to come over one as
he realizes that what he sees indicates
the action of some great power whose
source is not in the earth itself and
which comes no knows not whence
Every student of physics knows some
thing about Foucault's pendulum ex-
pertinent. for since ISL when it was
carried out in Paris. hardly general
textbook on physics has been issued
that does not give some details of this
famous test BY which the French
scientist showed that the earth rotates
lie went to the Pantheon in Paris and
s,,snended a pendulum from it's dome
on the bottom of the weight he placed
a fine point. SO that in case there was
any movement of the earth beneath i
it would trace lines in ring of sand
spread cut on the level floor The earth
! did move. and lines were traced which
showed that the plane Of oscillation
| varied with reference to the building: in
| fact the Pantheon was twisting around
| under the pendulrr
| Recently the experiment has been re-
| peated in America in St Paul's Cha pei
az Columbia University This chapel
| affords an excellent opportunity to make
| the test. as a ninety-one-foot pendulum
| can be suspended from the dome to the
floor. The physicist DR.. Charles Forbes
| of the university, used for his weight an
iron ball whose hollow was filled with
| lead This was suspended by steel
wire whose upper end was made fast in
the top Of the dome Beneath the ball
| on the floor was placed board some
thing over seven feet long and which
was centred on a pivot right beneath
the pendulum. a block covered with
printers ink was placed on the board
So that brush on the under side of the
ball would be linked each time the pen
dulun passed over it, The ball was
pulled back and tied with a string &c
nrevcnt its moving before the desired
time. and il was started on its journey
simnlv hv burning the string that helC
II At starting its plane of oscillation
was directly along the board beneath
At each end Of the board there was {
graduated arc. each division represent
ing hale a degree. The ball was set FIRE,
, when IL had no lateral vibration, an,
swung from end to end OF the board
Now If the earth actually rotate,
dilrnallv. the pendulum would have
certain independencc of motion. as
v,hrated IN space. and the earth mus
turn around beneath it; hence the brus)
= ! eneath IL would not make mark Il
exactly the same place as it passed owe
the graduated arcs at the end OF tn
hoard Nor did it do So The witnesSe
or mo experiment saw the brush pas
farther to the right on one arc and t