Mr. Hanky Panky displays to the audience a little fragment of a Tuscan
temple, being a slab of marble, at the ends of which stand two black
marble columns, two feet high, eight inches apart. Two glass tubes,
almost as fine as capillary ones, cross the intervening space, in a
direction inclined to the horizon.
A coloured liquid is distinctly seen running upwards through the lower
tube from one column to the other, and thence back again by the upper
tube. The colour is pleasing to the eye, and the regularity of the flow
well illustrates the theory of the circulation of the blood.
[Illustration: Fig. 117.]
It is impossible to believe there are pumps concealed in the pillars and
clockwork, while the low price at which such toys can be sold precludes
the idea of costly mechanism.
Indeed, the two glass tubes are what is commonly known as a pulse-glass.
The glass tube ends in glass bulbs full of coloured spirits of wine.
When one bulb is held in the hand and a slight inclination given to the
tube, the animal heat will excite the fluid, and drive it continually
from one ball to the other.
[Illustration: Fig. 118.]
As for Mr. Panky’s machine, he had filled the two columns, which were
hollow, with hot sand, which produced the same effect as the heat of the
hand. The sand will not cool for about half an hour, nowhere near which
time need the apparatus be kept before the audience.
There could be, with larger columns, small spirit-lamps or gas
introduced. Let a tube in the column fit into an orifice in your table,
and ignite the gas thus admitted by a spark of frictional electricity.
The heat would be continuous during many hours.