The Solar Concerto
In a large case, similar to what is used for dials and spring clocks,
the front of which, or at least the lower part, must be of glass,
covered on the inside with gauze, place a barrel organ, which when
wound up is prevented from playing by a catch that takes a toothed
wheel at the end of the barrel. To one end of this catch join a wire,
at the end of which is a flat circle of cork, of the same dimensions
with the insi
e of a glass tube, in which it is to rise and fall. This
tube must communicate with a reservoir that goes across the front part
of the bottom of the case, which is to be filled with spirits, such as
is used in thermometers.
This case being placed in the sun, the spirits will be rarefied by the
heat, and, rising in the tube, will lift up the catch or trigger, and
set the organ in play; which will continue as long as it is kept in
the sun; for the spirits cannot run out of the tube, that part of the
catch to which the circle is fixed being prevented from rising beyond
a certain point, by a check placed over it. Care must be taken to
remove the machine out of the sun before the organ runs down, that its
stopping may be evidently affected by the cold.
In winter it will perform when placed before the fire.
CURIOUS EXPERIMENTS WITH THE MAGIC LANTERN.
The construction of this amusing optical machine is so well known,
that to describe it would be superfluous; particularly as it can now
be purchased at a very reasonable expense, at any of the opticians':
but as many persons who have a taste for drawing might not be pleased
with the designs to be had at the shops, or might wish to indulge
their fancy in a variety of objects, which to purchase would become
expensive, we here present our readers, in the first place, with the
method of drawing them, which will be succeeded by a plain
description of some very diverting experiments.