o the small
ring, and begin to blow the No. 2 bubble. This must be started with the
pipe almost in contact with the inner ring, as the film on this ring
would destroy a bubble that had attained any size. Withdraw the pipe,
dip it into the liquid, and insert it into the inner bubble, taking care
to keep these two bubbles from meeting anywhere. Now blow a large
gas-bubble, which may rest against the top of No. 2 while it is growing.
No. 2 may now rest against the top of No. 1 without danger. Remove pipe
from No. 3 by gently lowering it, and let some gas into No. 2 to make it
lighter, and at the same time diminish the pressure between Nos. 2 and
3. Presently the small ring can be peeled off No. 2 and removed
altogether. But if there is a difficulty in accomplishing this, withdraw
the pipe from No. 2 and blow air into No. 1 to enlarge it, which will
make the process easier. Then remove the pipe from No. 1. The three
bubbles are now resting one inside the other. By blowing a fourth
bubble, as described above, against the fixed ring, No. 1 bubble will
peel off, and the three will float away. No. 1 can, while peeling, be
transferred to a light wire ring from which paper, &c. are suspended.
This description sounds complicated, but after a little practice the
process can be carried out almost with certainty in far less time than
it takes to describe it; in fact, so quickly can it be done, and so
simple does it appear, that no one would suppose that so many details
had to be attended to.

_Bubbles and Electricity._

These experiments are on the whole the most difficult to perform
successfully. The following details should be sufficient to prevent
failure. Two rings are formed at the end of a pair of wires about six
inches long in the straight part. About one inch at the opposite end
from the ring is turned down at a right angle. These turned-down ends
rest in two holes drilled vertically in a non-conductor such as ebonite,
about two or three inches apart. Then if all is right the two rings are
horizontal and at the same level, and they may be moved towards or away
from one another. Separate them a few inches, and blow a bubble above or
below each, making them nearly the same size. Then bring the two rings
nearer together until the bubbles just, and only just, rest against one
another. Though they may be hammered together without joining, they will
not remain long resting in this position, as the convex surfaces can
readily sq