C A T O P 
ttieti, women, &c. to increafe the sfl’eft of this ciftula; and 
two mirrors may alfo be placed on the fides, to convey an 
idea of great breadth as well as length. 
Animated Balls by simple Reflection. 
The machinery for this recreation being carefully cou¬ 
rt rufted, will produce one of the mod pleating and enter¬ 
taining amufeme-ntsof the kind. Procure a mahogany or 
other wooden box, as ABCD, fig. 13. about two feet high, 
and fifteen inches' wide ; and towards the upper front part 
make an opening at E, of eight or nine inches in height, 
and feven or eight incites in width, and in this fix a true- 
ground plane glafs. The depth, B D, of the box, as repre¬ 
sented in the profile of the figure, niuft: be. two feet, and a 
partition, S T, fixed in it, of the fame width, or fifteen 
inches, which will make an upper and under divifion in the 
box, and the latter be about one inch more than the for¬ 
mer. On the upper divifion, and near the extremity S, of 
the partition S T, place acrofs it a final 1 decoration, K S, 
of the figure of a front fcene of a theatre, with an opening 
of about nine inches in height, and feven inches wide. 
Place behind this a true ground-glafs mirror, K F, inclined 
in an angle of about thirty or forty degrees at mod, and it 
mud be of the fame width as the box, fo as to be fufti- 
ciently large to cover the opening of the front fcene, K S, 
when the eye is looking at it from E. Ornament the inte¬ 
rior fpace, KSTB, with fuch drawings or paintings as will 
contribute to the elegance and pleafure of the exhibition; 
and cover the top of the box, from K to B, with a frame 
containing a glafs ground with fine emery, or covered with 
a fine gauze, fo as the light may be admitted as much as 
poflible into the part KSTB. This being done, the next 
article to be placed is an inclined plane, of dimenfions pro¬ 
per to enter by a door made in the back G H. This plane, 
marked I M, fliould be more or lefs extended and inclined 
on the bafe C D, according to the greater or lefs inclina¬ 
tion which is given to the mirror K F". The plane may be 
fupported by two triangular props underneath, placed at 
IM. On the upper furface of this plane rnuft be painted 
or drawn a pleating fubjedft, fuch as a garden with flowers, 
or a piece of architecture, &c. in fuch a manner that it 
may appe irregular when viewed from E, by reflection from 
the inclined mirror above; and, as fome places may be per¬ 
ceived on the tides of the box, place horizontally towards 
K S decorations which may cover them. Cut in this in¬ 
clined plane a groove of about three tenths of an inch 
deep, equally large throughout, and fmoothly finiflied ; 
this groove mutt be fo dilpofed, that the ball, while de- 
feending, may make various windings, as reprefented at 
I M, and at latt, approaching the middle of its inferior 
fide C D, difappear, by going away into the groove or 
channel O P, and falling into a box, H, made to receive 
it in the wheel-work hereafter deferibed. Several ivory 
balls, rather more than half an inch in diameter, fhould 
be provided, which are to roll freely in the groove juft 
deferibed. It would be better to contrive the inclined 
plane I M fo as to admit of being railed or deprefled, to 
regulate the motion or velocity with which the bail fliould 
roll. In the infide of the box, about R, two fmall lamps 
or wax candles fliould be placed to illuminate the inclined 
plane, but no other part of the machine ; and, if refleCtors 
were placed behind it, it would be better. A door muft 
be made to admit thefe being taken out ; alfo a cover of 
tin, and a funnel for the con veyance of the fmoke. 
There niuft next be coiiftrucled an apparatus for incef- 
fantly remounting the balls. This apparatus is limilar to 
clock-work, and- contains a barrel with a coiled fpring, 
and wheel and pinions. There is no particular plan of 
the wheel-work ; the following is recommended and de¬ 
feribed by Mr. Guyot : provide a train of clock-work, 
contained in the brafs frame EFGH, fig. 14, compofed of 
a barrel, with a fpring and ratchet-wheel, and click, as in 
a common clork, fixed to the large wheel with teeth, A ; 
a fecond wheel, B, the pinion of which is connected with 
the wheel A ; a third wheel C, the pinion of which is 
Vol. III. No. 171. 
TRIGS. qxj 
turned by the wheel B ; and a fly, D, the pinion of which 
is turned by the wheel C; the wings of this fly fliopld be 
moveable, lo that a quicker or flower motion can be given, 
as may be neceflary. The axis of this v heel B fhould pro- 
jeiSt about half an inch beyond the tide of the frame, to 
receive the centre of the brafs arm H. I, fig. 15. which mu ft 
carry at its two extremities two boxes open towards II 
and I, and enlarging towards the bottom. In the interior 
part of thefe boxes fliould be fixed a fmall plate of brafs, 
moveable on a pivot F, and bent towards E; fo that, 
when 011s of the balls, having rolled down the inclined 
plane, (hull pafs into the bottom of one of the boxes, and, 
by its weight, fliall elevate the other end of the arm H I, 
•andraife it from its place where it was flopped, leaving by 
thefe means the branch at liberty to turn until its oppofite 
end fliall in its turn be flopped ; fo tint the upper ball 
thus remounted fliall roll out of its box into the upper part 
of the groove of the inclined plane ; from whence defeend- 
ing again, a ball will di(engage the fecond box ; and to on 
alternately, until the fpring contained in the barrel is un¬ 
coiled, which may be a number of times, in proportion to 
the number of the teeth in the wheels and pinions compri- 
fing the wheel-work. The fpring in the barrel maybe- 
wound up by a key placed on its axis, as in common clock¬ 
work. It is neceflary to add, that the adVion of one of the 
balls going into the box, difengages, at the inflatif, the flop 
that prevents its motion at the time, after diftharging the 
other at the top. The following is the ertedt of this recre¬ 
ation: when a ball is put into the groove at the top of (lie 
inclined plane, a perfon locking at it through the opening 
E, fig. 13, will imagine that it afeends by various windings 
contrary to the common gravity of bodies, and goes out at 
the top of the edifice-; which will appear more curious and 
pleafant, as the different windings are judicioufly adapted 
to the fubject painted on the plane. 
To exhibit the fame by a double Reflection. —This 
apparatus differs from the foregoing by only having a glafs 
mirror, inclined in an angle of 45 degrees, inflead of the in¬ 
clined plane, and by having that plane on which the balls 
roll placed in the part of tiie box T D. There may, be- 
fides, be placed towards S T, and in a pofition almoft hori¬ 
zontal, fmall columns, arbours, and other objedfs, made of 
brafs wire, placed at equal diftances, and joined together 
at the bottom by femi-circles, which muft be fo contrived 
as not to obftrufft the courfe of the ball. If the room in 
the box will admit, under the former may be placed ano- 
other fimilar arrangement of wires, fo thacthe ball, having 
rolled over the firft, may defeend to the other, which will 
produce a curious and ftrikingeffect, as the balls will feem 
to rencounter and pafs over each other. There muft, 
therefore, be two conduftors for the balls, fo that one ball 
may enter on one fide, and the other on the oppofite fide. 
There fliould alfo be a third condudtor, which, after the * 
ball has palled over the third piece, may carry it to the top 
of the inclined plane placed oppofite to the fecond mirror, 
that it may pafs down through all the windings. The 
wire for the balls fliould have a fmall inclination,about two 
lengths of an inch for afoot, and the difiance of the wires 
fomething lefs than tile diameter of the balls. Several va¬ 
riations may be made in the ornaments to this machine, 
and the balls may be coloured red or otherwife; the great- 
eft eff'edt being produced by an ingenious and per'iettly 
mechanical court ruftion of its various parts. 
The Apparii ion. 
Behind a partition, as at AB, fig. 16, place, fomewhat 
inclined, a concave mirror, E F, which muft beat leaf! ten 
inches in diameter, and its diftance equal to three-fourths 
from its centre. In the partition cut a fquare or circular 
opening, of feven or eight inches in diameter, directly op¬ 
pofite to the mirror. Behind this a ftrong light, fuch as 
from large candles, or Argand’s lamp, which niuft be fo- 
difpofed that it may not be feen at the opening, and illu¬ 
minate ftrongly an object placed at C, without giving light 
to the mirror. Beneath the aperture, place any object, C, 
1 1 A. that 
