Horizontal Wheels They Are Best When Their Fells Are Made
circular; in the middle of the top of the nave must be a pintle,
turned out of the same piece as the nave, two inches long, and equal
in diameter to the bore of one of the cases of the wheel; there must
be a hole bored up the centre of the nave, within half an inch of the
top of the pintle. The wheel being made; nail at the end of each spoke
(of which there should be six or eight) a piece of wood, with a groove
cut in
t to receive the case. Fix these pieces in such a manner that
half the cases may incline upwards and half downwards, and that, when
they are tied on, their heads and tails may come very nearly together:
from the tail of one case to the mouth of the other carry a leader,
which should be secured with pasted paper. Besides these pipes, it
will be necessary to put a little meal-powder within the pasted
paper, to blow off the pipe, that there may be no obstruction to the
fire from the cases. By means of these pipes the cases will
successively take fire, burning one upwards and the other downwards.
On the pintle fix a case of the same sort as those on the wheel; this
case must be fired by a leader from the mouth of the last case on the
wheel, which case must play downwards: instead of a common case in the
middle, you may put a case of Chinese fire, long enough to burn as
long as two or three of the cases on the wheel.
Horizontal wheels are often fired two at a time, and made to keep time
like vertical wheels, only they are made without any slow or dead
fire; 10 or 12 inches will be enough for the diameter of wheels with
six spokes.