The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1895-08-11
SECOND PAPER.

SECOND PAPER.
Kinetic stability, as / have already ex-
planned, is well Known in pyramic science,
and do not claim any originality IN the
use of the term in connection with the
principle have discovered. When we see
bicycle going at the rate of ten miles an
hour and observe how it keeps in an up
right position, and requires considerable
force exerted sideways to push it from the
upright position; and when we consider
that if the same bicycle is at rest, or not
moving relative to the earth, it requires to
be supported to prevent it from falling
sideways, we then become cognizant of a
new force, which is called kinetic stability.
The difference in the two cases depends
not merely on the motion or momentum
given to the bicycle, but to its independent
kinetic energy.
If the same bicycle were carried over the
same course at the same speed, say ten
miles an hour, in railway car, then,
although the bicycle relative to the earth
had the same momentum as before, yet its
kinetic energy is nothing, and its kinetlc
stability is nothing; you have still got to
support the bicycle to keep it from falling
sideways.
apparently inherent power which it has
while in motion to keep itself upright, and
if we never saw bicycle unless while 1t
was in motion it would be very difficult to
persuade us that its kinetic stability was
an acquired force; like the ancient phil
osophers who before the days of Newton
believed that all the heavenly bodies were
endowed with intrinsic motion, or what Is
now called a specific inherent quality of
motion, that they were in fact virtually
little gods, who by virtue of their inherent
qualities ruled the destinieS of individuals
and nations.
Our experience in the case of the bicycle,
of course, teaches us that this peculiar con-
dition of stability acquired by its motion
is not an intrinsic quality in the bicycle.
And as we know by experiment that 1t
changes with the change of speed and fol-
lows some law depending not merely on
speed, but on speed and mass together, we
call it a kinetic condition. If 1T had only
depended on speed we would have called 1t
a kinematical condition.
The amusing toy called gyroscope is an
other case of motion producing stability,
and when the celebrated French scientist
NJ. Leon Foucault showed the action of his
gyroscope at meeting OF the British Asso-
citation forty-three years ago 1T gave the
scientific world such sensation that the
bewildering effects are still diseernlble to
this day.
Although all persons from their child
hood are familiar with the stability OF
spinning-top, yet the leading scientists OF
forty years ago considered that the pecu-
liar motions of the eyroscope were per-
formed in violation of the accepted laws OF
motion. The pecuharities, however, were
only apparent, and have since yielded to
mathematical treatment. They can be
shown to be special case of the we'll
known laws of the superposition of rota-
tions round different axes.
I well remember the surprise 1 got
when attending the university twenty
eight years ago when asked by the protes-
sor of physics to take hold of what APP
peared to be a closed sheet-iron box and
give it twist round horizontal axis. l
seized it with both hands. and, in twisting
it round, found | had something more
than box to handle. It's reaction against
my action seemed more like the force of
living thing than that of dead matter, and
the more tried to twist it over the more
it squirmed and wriggled, as if l was
wrestling with. a human being.
The box was Sir William Thompson's