ACR 
ACO 
wire, and shut by a spring. The wire 
must pass through the figure, and under the 
floor, to come up behind the partition. 
Let a person properly instructed be placed 
behind the partition, near the mirror ; any 
ohe may now whisper into the ear of the 
image, with the assurance of being an- 
swered. The deception is managed by 
giving a signal to the person behind the par- 
tition, who by placing his ear to the focus 
I, of the mirror GH, will hear distinctly 
what tlie other said, and moving the jaw of 
the statue by the concealed wire, will re- 
turn the answer directly, which will be 
heard distinctly by the first speaker. 
Ex. 2. Let two heads of plaster of Paris 
be placed on pedestals, on opposite sides of 
a room. A tin tube of an inch in diame- 
ter must pass from the ear of one head 
through the pedestal under the floor, and 
go up to the mouth of the other. When a 
person speaks low into the ear of one bust, 
the sound is reverberated through the length 
of the tube, and will be distinctly heard by 
any one who shall place his ear to the mouth 
of the other. The end of the tube which is 
next the fear of the one head should be 
considerably larger than that end which 
comes to the mouth of the other. If 
there be two tubes, one going to the ear, 
and the other to the mouth of each head, 
two persons may converse together, by ap- 
plying their month and ear recipiocally to 
the mouth and ear of the busts, while other 
people standing in the middle of the room, 
between the heads, will not hear any part 
of the conversation. 
Ex. 3. Fig- 7 is a representation of the 
Eolian harp, which was probably invented 
by Kircher. This instrument may be made 
by almost any carpenter ; it consists of a 
long narrow box of very thin deal, about 
five or six inches broad, and two inches 
deep, with a circle in the middle of the up- 
per side of an inch and a half in diameter, 
in winch is drilled small holes. On this side 
seven, ten, or more strings of very fine gut 
are stretched over bridges at each end, like 
the bridge of a fiddle, and screwed up or re- 
laxed with screw-pins. The strings are all 
tuned to one and the same note ; and the 
instrument is placed in some cun ent of air, 
where the wind can pass over its strings 
with freedom. A window, of which the 
width is exactly equal to the length of the 
harp, with the sash just raised to give the 
air admission, is a proper situation. When 
the air blows upon these strings with diffe- 
rent degrees of force, it will excite different 
tones of sound ; sometimes the blast brings 
out all the tones in full concert, and some- 
times it sinks them to the softest mur- 
murs. 
There are different kinds of these instru- 
ments; one, invented by the Rev. W. Jones, 
has the strings fixed to a sounding-board, or 
belly, within a wooden case, and the wind 
is admitted to them through an horizontal 
aperture. In this form the instrument is 
portable, and may be used any where in 
the open air. The tension of the strings 
must not be great, as the air, if gentle, has 
not sufficient power to make them vibrate, 
and if it blows fresh, the instrument (foes 
not sing, but scream. See Harmonics. 
ACQUITTAL, in law, is a deliverance 
or setting free from tlie suspicion of guilt ; 
as one who is discharged of a felony is said 
to be acquitted thereof. 
Acquittal is either in f act, or in law ; in 
fact, it is where a person, on a verdict of 
the jury, is found not guilty ; in law, it is 
when two persons are indicted, one as a 
principal, &c. the other as accessary : here 
if the former be discharged, the latter of 
consequence is acquitted. 
ACQUITTANCE,- a discharge in writ- 
ing for a sum of money, witnessing that the 
party is paid the same. 
A man is obliged to give an acquittance 
on receiving money : and a servant’s ac- 
quittance for money received for the use of 
his master shall bind him, provided the 
servant used to receive his master’s rents. 
An acquittance is a full discharge, and bars 
all actions, &c. 
ACE 1 D/E, in entomology, the name by 
which Linnaeus has distinguished the first fa- 
mily of the grylius, or the cricket, properly 
so called : the characters of which are, that 
the head is conical and longer than the 
thorax, and the antennae ensiform, or sword- 
shaped. Of this family there are eight spe- 
cies, none of which are found in Britain. The 
insects of this family feed on other insects. 
See Gryixus. 
ACROCHORDUS, in natural history, a 
genus of the class Amphibia, and of the or- 
der Serpents. There are but three species, 
viz. A. javanicus, warted snake, brown, be- 
neath paler ; the sides obscurely variegated 
with whitish. It inhabits java, chiefly 
among the pepper plantations ; grows 
sometimes to seven feet long. The warts, 
by means of a magnifying glass, appear to 
be convex carinate scales, and the smaller 
ones are furnished with two smaller promi- 
nences, one each side the larger. Head some- 
what flattened, hardly wider than the neck, 
body gradually thicker towards the middle, 
