115 
M O T I O N. 
turns in the direftion a be, the weights A, B, and C, will 
recede from the centre ; consequently, as they aft with 
more force, they will carry the wheel towards that fide ; 
and, as a new lever will be thrown out in proportion as 
the wheel revolves, it thence follows, lay they, that the 
wheel will continue to move in the fame direftion. But, 
notwithllanding the Specious appearance of this realon- 
ing, experience has proved that the machine will not go ; 
and it may indeed be demonftrated that there is a certain 
poiition, in which the centre of gravity of all thefe weights 
i’s in the vertical plane palling through the point of fuf- 
penlion, and that therefore it mult Hop. 
The cafe is the fame with the following machine, which 
it would appear ought to move alfo incelTantly. In a cy- 
lindric drum, in perfieft equilibrium on its axis, are form¬ 
ed channels as feen in fig. 6. which contain balls of lead, 
or a certain quantity of quicklilver. In confequence of 
this difpolition, the balls or quicklilver mult, on the one 
fide, afeend by approaching the centre; and on the other 
mult roll towards the circumference. The machine then 
ought to turn inceffantly towards that fide. 
A third machine of this kind is represented fig. 7. It 
•confilts of a kind of wheel formed of fix or eight arms, 
proceeding from a centre, where the axis of motion is 
placed. Each of thefe arms is furnilhed with a receptacle 
in the form of a pair of bellows; but thole on the oppo- 
fite arms Itand in contrary directions, as feen in the figure. 
The movable top of each receptacle has affixed to it a 
weight, which Ihuts it in one fituation and opens it in the 
other. In the lall place, the bellows of the oppofite arms 
have a communication by means of a canal, and one of 
them is filled with quicklilver. Thefe things being fup- 
pol'ed, it is vilible, that the bellows on the one fide mult 
open, and thole on the other mult Ihut; conlequently the 
mercury will pafs from the latter into the former, while 
the contrary will be the cafe on the oppofite fide. It 
might be difficult to point out the deficiency of this rea- 
foning; but thofe acquainted with the true principles of 
mechanics will not hefitate to bet a hundred to one that 
the machine, when conftrufted, will not anfwer the in¬ 
tended purpole. 
The defcription of a pretended perpetual motion, in 
which bellows, to be alternately filled with and emptied 
of quicklilver, were employed, may be leen in the Journal 
des Sljavans for 1685. It was refuted by Bernoulli, and 
fome others, and it gave rile to a long difpute. The belt 
method, which the inventor could have employed to de¬ 
fend his invention, would have been to conftruft it, and 
Ihow it in motion ; but this was never done. 
Almoft every one has heard of Orfyreus's wheel, a ma¬ 
chine lo called from its inventor, which he afferted to be a 
perpetual motion. This machine, according to the ac¬ 
count given of it by Gravelande, in his CEuvres Philolo- 
phiques, (publilhed by Allemand, Amlt. 1774,) confided 
externally of a large circular wheel, or rather drum, 12, 
feet in diameter, and 14 inches deep; it was very light, 
being formed of an affemblage of deals, having the inter¬ 
vals between them covered with waxed cloth, to conceal 
the interior parts of it. The two extremities of an iron 
axis, on which it turned, reded on two fupports. On giv¬ 
ing a flight impulfe to the wheel, in either direction, its 
motion was gradually accelerated ; lb that after two or 
three revolutions it acquired fo great a velocity as to 
make 25 or 26 turns in a minute. This rapid motion it 
aftually preferved during the fpace of two months, in a 
chamber of the landgrave of Hefle, the door of which 
was kept locked, and lealed with the landgrave’s own leal. 
At the end of that time the door was unlocked, and the 
machine was found in motion. Gravefande, who had 
been an eye-witnefs to thefe circumftances, examined all 
the external parts of it, and was convinced that there 
could not be any communication between it and any 
neighbouring room. Orfyreus however was fo incenfed, 
or pretended to be fo, that he broke the machine in pieces, 
iuid wrote on the wall, that it was the impertinent curio- 
fity of profeffor Gravefande which made him take this 
ilep. The prince of Hefle, who had feen the interior 
parts of this wheel, but fworn to lecrefy, being alked by 
Gravefande, whether, after it had been in motion for fome 
time, there was any change oblervable in it, and whether 
it contained any thing that indicated fraud or deception, 
anfwered both queltions in the negative, and declared 
that the machine was of a very Ample conltruction. This, 
however, affords no proof in favour of a perpetual mo¬ 
tion ; for, as clocks can be made to go a year without 
being wound up, Orfyreus’s wheel might eafiiy go two 
months, and even more. It was afferted, in one of the 
journals of that day, that an Englifhman had offered 
80,000 crowns for this machine ; but that Orfyreus re- 
fufed to fell it at that price. In this (fays Montucla) he 
certainly afted wrong, as there is reafon to think that he 
obtained by his invention neither money, nor even the 
honour of having dilcovered the perpetual motion. 
The Academy of Painting, at Paris, poffefled a chock, 
which had no need of being wound up, and which might 
be confidered as a perpetual motion, though it was not fo. 
But this requires fome explanation. The ingenious au¬ 
thor of this clock employed the variations in the ftate of 
the atmofphere, for winding up his moving weight: va¬ 
rious artifices might be deviled for this purpole; but this 
is no more a perpetual motion, than if the flux and reflux 
of the lea were employed to keep the machine continually 
going; for this principle of motion is exterior to the ma¬ 
chine, and forms no part of it. 
The newlpapers of the prefent month inform us, that 
the perpetual motion, fo long fought for in vain, appears 
capable of being effefted through the medium of galvanij'm! 
“ A French phyfician has in his cabinet two galvanic 
piles, fixteen inches high, which alternately attraft a 
pretty heavy beam ; and the continual ofcillation of the 
beam gives motion to a pendulum,' which has never 
Hopped for the lalt three years. The phyfician is at pre¬ 
fent labouring to give to this movement an ilochronifm 
which may render it more ufeful.” Morn. Chron. Aug. 
21, 1817. 
But enough has been faid on this chimera of mechanics. 
We fincerely hope that none of our readers will ever lofe 
themfelves in the ridiculous and unfortunate labyrinth of 
l'uch a refearch. To conclude ; it is falfe that any reward 
has been promifed by the European powers to the perfon 
who lhall dilcover the perpetual motion ; and the cafe is 
the fame in regard to the quadrature of the circle. It is 
this idea, no doubt, that excites fo many to attempt the 
lolution of thefe problems; and it is proper they ihould 
be undeceived. Muntucla's Recreations in Mathematics , 
tranftated by Dr. Hutton ; vol. ii. 
Animal Motion, that which is performed by fentient 
beings at the command of the mind or will. 
Though all the motions of animals, whether voluntary 
or involuntary, are performed by means of the mufcles 
and nerves, yet neither thefe nor the fubtile fluid which 
relides in them are to be accounted the ultimate lources 
of animal motion. They depend entirely upon the mind, 
for thofe motions which are properly to be accounted 
animal. All the involuntary motions, fuch as thofe of 
the blood, the heart, mufcles, organs lubfervient to re- 
fpiration and digeltion, &c. are to be claffed with thofe of 
vegetables; for, though no .vegetables have them in fucli 
perfeftion as animals, there are yet traces of them to be 
found evidently among vegetables, and that fo remark¬ 
ably, that fome have imagined the animal and vegetable 
kingdoms to approach each other fo nearly that they 
could fcarce be diffinguilhed by a philofophic eye. 
Though the motions of animals, however, depend on 
the aftion of the mind or of the will, external objefts 
feem originally to have the command of the mind itfelf; 
for, uniefs an animal perceive fomething, it will not be 
inclined to aft. By means of the ideas once received, in¬ 
deed, and retained in the memory, it acquires a felf-mov- 
ing power, independent of any objeft prefent at the time, 
which 
