The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1905-10-16
SWING 100 FEET.
One of Longest Pendulums
Known Is Being Erected.
Suspended in an Air Shaft at
State House.
TRY FOUCAULF TEST.
Prof. LOvewell to Illustrate
Revolution of the Earth.
How This Delicate Experiment
Is Made.
TRY FOUCAULE TEST.

By permission of the executive couIl-
ell of the state J. 7. Lovewell, secretary
of the Kansas Academy of Science, will
have swung in one of the air shafts at
the state house one of the longest pen
dnlrlns In the United States, for the
purpose of performing the Foucault
experiment for illustrating the revolu-
ton of the earth. The pendulum will
be upwards of 100 feet long, and the
pendulum bob will be made of a huge
chunk of lead weighing SO pounds.
1t is the object of Prof. Lovewen to
secure from his experiments the ma
terial for a scientific paper to be pre-
scented at the next meeting of the Kan
sas academy.
The pendulurn-bob will swing on
steel piano wire from the top of the
air shaft to the basement 1t will have
a sweep of about IA feet, ana II IS esu-
mated that when once started It VIII
swing for half a day without stopping
The pendulum will be so arranged Ihat
at the lowest point of its swing the
bob will trace its course on SMOKED
glass and this is where the scientists
obtain their tangible evidence that the
earth is really turning ON its axis The
pendulum will not trace the same
straight line back and forth put IN
the lapse of a number of hours, VIII
trace double fan-shaped inquire on
the glass. The tracing is made with
geometrica1 accuracy.
This pendulum experiment IS pdseu
on the old theory of inertia; that
body once started to moving in a given
direction will tend to continue IN that
same direction unless arrested by some
other force. When once started me
pendulum continues to SWING IN the
same direction. Meantime the earIh
turns around underneath it, and thus
the smoked glass upon which the pen
duIuIn traces its course IS IN q sligiltly
different position every time the pen
duIuua passes over it. This results IN
tracing like two triangles placed end
to end. -..
successfully" says Prof. LoVeWeii,
certain conditions are necessary
which it is difficult to obtain In the
first place. the pendulum must pc very
long; the longer the petler. A. A us
also be swung from very solid ana
substantial support, in such place
that it viii not be affected by air cur
rents I believe that these conditions
can be obtained with unusual perez
ton in one of the air shafts at the
+ state house, which extend from the
basement to the root me WINDOWS
/ opening into this areaway viii all pc
closed during the experiment. me
pendulum will be swung from heavy
/ oak beam, about 20 feet long, placed
across the top of the areaway and
fastened solidly.
Another important mater 70 Dc
taken into consideration is the stretch
of the wire In wire of this length,
the streten may be several feet when
the pendulum is attached. The
1 length OF the wire must therefore De
carefully adjusted until the stretch is
ali taken out and for any changes Of
/ length.
1T is also important that pendulum
be suspended in such a way tnat II vii
swing from an exact point and not
swerve To accomplish this, shall
/ have a good sized hole through the
oak beam, and on top OF the hoie an
iron plate. Derforated by a hole just
large enough to admit the passage Of
the wire. The wire viii pass through