A C O U S T I 
be a tiri tube of an inch diameter, that mud pafs from the 
ear of one head, through the pedeftal under the floor, and 
go up to the mouth of the other. Obferve, that the end 
of the tube which is next the ear of the one head, (hould 
be confiderably larger than that end which comes to 
the mouth of the other. Let the whole be fo difpofed 
that there may not be the leaft fufpicion of a communi¬ 
cation. 
Now, when a perfon fpeaks, quite low, into the ear of 
one buft, the found is reverberated through the length of 
the tube, and will be diftin&ly heard by any one who (hall 
place his ear to the mouth of the other. It is not neceflary 
that the tube (hould come to the lips of the buft. If 
there be two tubes, one going to the ear, and the other 
to the mouth, of each head, two perfons may converfe 
together, by applying their mouth and ear reciprocally to 
the mouth and ear of the bufts; and at the fame time 
other perfons that (land in the middle of the chamber, 
between the two heads, will not hear any part of their 
converfation. This contrivance forms one of the moll 
pleafing illufions now exhibited at Merlin’s Mufeum of 
Mechanical Entertainments, in London. 
III. Place a buft on a pedeftal in the corner of a room, 
and let there be two tubes, as in the foregoing amufement, 
one of which mud go from the mouth and the other from 
the ear of the buft, through the pedeftal, and the floor, 
to an under apartment. There may be likewife wires that 
go front the under jaw and the eyes of the buft, by which 
they may be eafily moved. 
A perfon being placed in the under room, and at a fig- 
nal given applying his ear to one of the tubes, will hear 
any queftion that isafked, and immediately reply; mov¬ 
ing, at the fame time, by means of the wires, the mouth 
and the eyes of the buft, as if the reply came from it. 
IV. In a large cafe, fuch as is ufed for dials and fpring- 
clocks, the front of which, or at leaft the lower part of 
it, mud be of glafs, covered on the infide with gauze, let 
there be placed a barrel-organ, which, when wound up, is 
prevented from playing, by a catch that takes a toothed 
wjieel at the end of the barrel. To one end of this catch 
there mud be joined a wire, at the end of which there is 
a flat circle of cork, of the fame dimenfion with the in¬ 
fide of a glafs tube, in which it is to rife and fall. This 
tube mult communicate with a refervoir that goes acrofs 
the front part of the bottom of the cafe, which is to be 
filled with fpirits, fuch as is ufed in thermometers, but 
not coloured, that it may be the better concealed by the 
gauze. 
This cafe being placed in the fun, the fpirits will be ra- 
a c a 
ACQS, a town at the foot of the Pyrenean mountains, 
in the government, of Foix in France. It takes its name 
from the hot waters in thefe parts. Lat. 43. o. Ion. 1. 
40. E. 
ACQUA, a town in Tufcany, noted for warm baths. 
Lat.43. 45-N. Ion. 12.10. E. 
Ac qjja-che-fa vella, a celebrated fountain in Cala¬ 
bria. It is near the mouth of the river Crata, and the 
ruins are called Sibari Rovinata. 
To ACQUAINT, v. a. [accointer, Fr. ] To make fami¬ 
liar with; applied either to perfons or things. It has with 
before the objetSL —Acquaint yourfelves with things ancient 
and modern, natural, civil, and religious, domeftic and ra¬ 
tional; things of your own and foreign countries; and, 
sibov# all, be well acquainted with God and yourfelves; 
learn animal nature, and the workings of your own fpirits. 
Watts .—To inform. With is more in life before the object 
than of. 
ACQUAINTANCE,/, [acccintance, Fr,] The ftate of 
C S. 9£ 
refied by the heat; and, riftng in the tube, will lift up the 
catch or trigger, and fet the organ in play: which it will 
continue to do as long as it is kept in the fun; for the fpirits 
cannot run out of the tube, that part of the catch to which 
the circle is fixed being prevented from riling beyond a 
certain point by a check placed over it. 
When the machine is placed againft the fide of a room on 
which the fun (bines ftrong, it may conftantly remain in 
the fame place, if you inclofeitina fecond cafe, mdde of 
thick wood, and placed at a little diflance from the other. 
When you want it to perform, it will be only neceflary to 
throw open the door of the outer cafe, and expofe it to 
the fun. 
But if the machine be moveable, it will perform on all 
feafons by being placed before the fire ; and in the winter 
it will more readily (top when removed into the cold. 
A machine of this fort is faid to have been invented by 
Cornelius Dreble, in the laft century. What the con- 
ftruttion of that was, we know not; it might very likely 
be more complex, but could fcarcely anfwer the intention- 
more readily. 
V. Under the keys of a common harpfichord.Iet there 
be fixed a barrel, fomething like that in a chamber-organ, 
with (tops or pins correfponding to the tunes you would 
have it play. Thefe (tops mult be moveable-, fo that the 
tunes may be varied at pleafure. From each of the keys 
let there go a wire perpendicular down: the ends of thefe 
vrires muft be turned up for about a quarter of an inch. 
Behind thefe wires let there be an iron bar, to prevent 
them from going too far back. Now, as the barrel turns 
round, its pins take the ends of the wires, which pull 
down the keys, and play the harpfichord. The barrel 
and wires are to be all inclofed in a cafe. 
In the chimney of the fame room where the harpfichord 
(lands, or at leaft in one adjacent, there mud be a fmoke 
jack, from whence comes down a wire, or cord, that, paf- 
fing behind the wainfeot adjoining the chimney, goes un¬ 
der the floor, and up one of the legs of the harpfichord, 
into the cafe, and round a fmall wheel fixed on the axis of 
that firft mentioned. There (hould be pullies at different 
diftances, behind the wainfeot and under the floor, to fa¬ 
cilitate the motion of the cord. 
This machinery may be applied to any other keyed in- 
ftrument, as well as to chimes, and to many other purpofes 
where a regular continued motion is required. 
An inftrument of this fort may be confidered as a per¬ 
petual motion, according to the vulgar acceptation of the 
term ; for it will never ceafe going till the fire be extin- 
guifhed, or Come parts of the machinery be worn out. 
A C Q_ 
being acquainted with; familiarity, knowledge. It is ap¬ 
plied as well to perfons as things, with the particle with. 
—Our admiration of a famous man letfens upon our near¬ 
er acquaintance with him; and we feldom hear of a cele¬ 
brated perfon, without a catalogue of fome notorious 
weaknefies and infirmities. Addj'on _Familiar knowledge, 
(imply without a prepofition. A (light or initial know¬ 
ledge, (hort of friendfhip, as applied to perfons. The 
perfon with whom we are acquainted; him of whom we 
have fome knowledge, without the intimacy of friendfhip. 
In this fenfe, the plural is in fome authors, acquaintance , 
in others, acquaintances .—That young men travel under 
fome tutor, 1 allow well, fo that he be fuch a one that 
may be able to tell them, what acquaintances they are to 
feek, what exerciles or difc-ipline the place yieldeth. Bacon. 
ACQUAINTED, adj. Familiar, wellknown; not new.; 
Now call we our high court of parliament; 
That war or peace-, or botli at once, may be 
As things acquainted and familiar to us. Shakefpeace. 
ACQUEPENDENTE, 
