ng when well executed, so they are highly disgusting when
imperfect. These are the most difficult pieces to cut out.

To produce the apparent motion of these cascades, instead of drawing a
spiral, you must have a slip of strong paper, of such length as you
judge convenient. In this paper there must be a greater number of
holes near each other, and made with pointed tools of different
dimensions.

At each end of the paper, a part of the same size with the cascade
must be left uncut; and towards those parts the holes must be made at
a greater distance from each other.

When the cascade that is cut out is placed before the scroll of paper
just mentioned, and it is entirely wound upon the roller, the part of
the paper that is then between being quite opaque, no part of the
cascade will be visible; but as the winch is gently turned, and
regularly round, the transparent part of the paper will give to the
cascade the appearance of fire that descends in the same direction;
and the illusion will be so strong, that the spectators will think
they see a cascade of fire; especially if the figure be judiciously
cut out.

_The Oracular Mirror._

Provide a round mirror of about three inches in diameter and whose
frame is an inch wide. Line the under part of the frame, in which
holes are to be cut, with very thin glass; behind this glass let a
mirror of about two inches diameter be placed, which is to be
moveable, so that by inclining the frame to either side, part of the
mirror will be visible behind the glass on that side.

Then take Spanish chalk, or cypress vitriol, of which you make a
pencil, and with this you may write on a glass, and rub it off with a
cloth, and by breathing on the glass, the writing will appear and
disappear several times. With this pencil write on one side of the
mirror, before it is put in the frame, the word _yes_, and on the
other side, _no_; and wipe them off with a cloth.

You propose to a person to ask any question of this mirror that can be
answered by the words _yes_ or _no_. Then turning the glass to one
side, and putting your mouth close to it, as if to repeat the question
softly, you breathe on it, and the word yes or no will immediately
appear. This mirror will serve for many other agreeable amusements.

_The Hour of the Day or Night told by a suspended Shilling._

However improbable the following experiment may appear, it has been
proved by repeated trials:

Sling a shilling or six