To Represent Cascades Of Fire
In cutting out cascades, you must take care to preserve a natural
inequality in the parts cut out; for if, to save time, you should make
all the holes with the same pointed tool, the uniformity of the parts
will not fail to produce a disagreeable effect. As these cascades are
very pleasing when well executed, so they are highly disgusting when
imperfect. These are the most difficult pieces to cut out.
To
roduce 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.