ORGAN. 
: on the other extremity of 
this eet is a fly-wheel x, to regulate the movement, and 
a crank, which by a rod, x, communicates motion to one end 
of the bellows C, at the end a, fig.1. There is alfo another 
crank at x, bent at right angles to the former: 
communicates, by a horizontal rod, with a bent lever behind 
the inftrument, which works the other adh . ami at A, 
fo that both pair, A, C, are in conftant mo 
The refervoir, D, is ad fize of the whole oor of the organ, 
and is common to all the three pair of bellows : it confiits of 
a large flat board, ened by folded ey on all fides to 
the floor board, forming a large chamber as the reception 
of the air from che different bellows. weight of this 
board, always refting upon the included air, cue a preffure 
of air, affords a regular and equable fupply to the 
i e action of 
ing into the bellows below. By this m 
never be in danger of burftin A ftrin 
top board of the refervoir, and paffes over a fmall pulley y, 
( ig. I.) fixed on the end of a light fpindle which comes 
through the ey of the inftrument over the keys, and has 
a hand er index at y, pointing to marks upon a fmall dial 
plate, ac diesgne the height to which the top has rifen, and, 
confequently, the quantity of air in the refervoir, fo that 
this index ferves as a guide to the performer, to blow 
oe as is neceflary to keep the refervoir full, but no more. 
wind cheft, F, is now to be defcribed: this is a fhallow 
a as the fection fhews, the whole fize of the inftrument, 
ps) 
on 
and are kept fhut by a {ma'l wire {pring w, Ug. 1.) applied 
The valves are opened by means of {mall wires, 5, 
down from them, through the bottom of the wind 
cheft, and oS as before ‘mentioned, with the levers N. 
bias 
g them to 
Pipes of aie tones, but toned to Ge fame note. 
inftrument before ie there are 
there are ten fy{tems of pipes 
h; 
by drawing the flider endways a {mall diftance, de Gate €6 
between the holes in the ftcp apply themfelves over the 
paflages, and fhut them all up at once. Each ftop or flider 
opens paffages to a fet of pipes, confifting of one pipe 
anfwering to each of the notes of the finger-keys: thefe 
pipes are gradually diminifhed in length and fize, from the 
largeit bafs note to the {malleft treble, as is fhewn in the 
figures at G, H, I, K, L, M, in different rows, fome of which 
contain only about half the number of pipes correfponding 
with the finger-keys, the remaining numbers being placed 
in other rows for want of room, and the upper board 
ee, called the found board, on which the pipes are placed, 
eac 
fituated exaélly over it, as snd ed ve 
er of pipes is fo great, as too 
found board, they muft adie he placed as the room will 
fame sale it will be obferved in SE: 2, that 
O placed clofe together in a {mall 
d the valves 2, occupy the 
on 
the ee ig fame effet will be siempre on the inftrument, 
viz. fhutting off or opening the row of pipes to which they 
belong. The three fets of fliders are for three different 
purpoles ; thus the loweit fet is moved by handles, or 
inds, of metal and of woods 
are a fquare trunk of deal wood A B, (fe- 3.) clofed nee one 
end by a moveable plug of wood D, and at the other by a 
piece of wood E, containing a crooked Paflage to bring 
air to the pipe, through the tube piece of 
oak board glued to the block E, called te cap, and hol- 
he 
ut, to communicate with t rocked paflage, 
w 
it is s dvided ie the edge 
which is’ cut as fharp as pofhble for that purpofe, and 
which is cxaétly in the fame line with the ori 
the air is emitted. The found is produced by the vibration 
of the air which is contained in the trunk A B, and by in- 
creafing or diminifhing the length of ce trunk the i : 
tere 
