MECHANICS. 
fafture perhaps during his whole life ; the next another 
and fo on : hence each executes his part well, and very 
quick; and the work belt done, by being done fo quick, 
is alfo the cheapelt. Improvements alfo will be made, 
both in celerity and fafiiion ; as among many workmen 
fome will be found fuperior to the reft in judgment, ge¬ 
nius, and tafte, “ If foreign manufactures,” fay the edi¬ 
tors of the Encyclopedic methodique, “ could not vie 
with the (ilk-works at Lyons, it is not from not knowing 
how they work there : there are every-where the fame 
trades, the lame filks, nearly the fame methods of weav¬ 
ing, winding, throwing, Se c. but it is at Lyons only that 
30,000 workmen are collected and all employed upon the 
manufacture and improvement of the fame material.” A 
watch for common purpofes is fold for 5I. and includes 
the labour of between twenty and thirty perfons : but 
upon the firft appearance of a watch upon a new principle, 
wherein the inventor mull take feveral of the branches 
upon himfelf, and can employ none but a few prime work¬ 
men, the price will be from one to three hundred guineas ; 
though perhaps, in the courfe of a few years, when the 
principle becomes well known, and familiar to the gene¬ 
rality of workmen, it may be fold for ten or twelve. 
Let us then at length do juftice to artifts and artifans. 
The liberal arts have fufficiently fung their own praifes ; 
mow may they employ the voice that remains to them in 
founding the praifes of the mechanical arts. It is the bufi- 
nefs of the liberal arts to draw the mechanical arts out of 
that obfcurity and contempt in which prejudice has fo 
long left them. Artifts have thought themfelves defpi- 
cable becaufe they have been defpifed. Let them enter¬ 
tain a proper opinion of themfelves; and we (hall fee 
them execute works It ill more perfeft. 
MECHAN'ICALLY, adv. According to the laws of 
mechanifm.—Later philofophers feign hypothefes for ex¬ 
plaining all things mechanically , and refer other caufes to 
metaphyfics. Newton. 
MECHANICALNESS, /. Agreeablenefs to the laws 
of mechanifm. Meannefs. 
MECHANI'CIAN, /. [ mechanicien , Fr.] A man pro- 
fefting or ltudying the conftruflion of machines; one fu¬ 
perior to a common mechanic.-—Some were figured like 
male, others like female, fcrews, as mechanicians fpeak. Boyle. 
!tal. me- 
. art, or 
the laws 
of the equilibrium and motion of folid bodies ; the forces 
by which bodies, whether animate or inanimate, may be 
made to aft upon one another; and the means by which 
thefe may be increafed lo as to overcome fuch as are more 
powerful. The term mechanics was originally applied to 
the doctrine of equilibrium. It has by fome late writers 
been extended to the motion and equilibrium of all bo¬ 
dies, whether folid, fluid, or aeriform ; and has been em¬ 
ployed to comprehend the fciences ot hydrodynamics and 
pneumatics. Hence we comprehend Hydrostatics un¬ 
der this article. 
INTRODUCTION. 
As the fcience of mechanics is intimately connefted 
with the arts of life, and particularly with thole which 
exift even in the rudelt ages ot fociety, the conltruftion 
of machines mull have arrived at conliderable perfeftion 
before the theory of equilibrium, or the ftmplelt proper¬ 
ties of the mechanical powers, had engaged the attention 
of philofophers. We accordingly find that the lever, the 
pulley, the crane, the capltan, and other fimple machines, 
were employed by the ancient architects in railing the 
materials ol their buildings, long before the dawn of me¬ 
chanical fcience; and the military engines of the Greeks 
and Romans, fuch as the catapultre and baliftse, exhibit 
an extenfive acquaintance with the conltruftion of com¬ 
pound machinery. In the fplendid remains of Egyptian 
architefture, which in every age have excited the admira¬ 
tion, of the world, we perceive the molt furprifing marks 
MECHAN ICS,y. \_mechanique, Fr. meccanica, I 
tanica, Spai^. of mechanicus, Lat. from Gr 
inttrument of art.] The fcience which treats of 1 
of mechanical genius. Difficulties gave birth, to refources. 
For inltance, when Ctefiphon, the architeft employed in 
building the temple of Ephefus, had procured the pillars,, 
which were to fupport or adorn that vaft edifice, t.o be 
falhioned in the quarries, and they were now fo be con¬ 
veyed to Ephefus, he was aware, that, i ’ they were placed 
on a comrnon waggon, their enormous weight would fink 
the wheels into the ground, and render them incapable of 
moving Accordingly he had recourfe to another very 
Ample mode. He fixed into the centres of the oppofite 
ends of a pillar two itout iron pins, which turned in holes 
cut in two long beams of wood joined together by a crofs- 
piece. Oxen being then harnelTVd to this fort of frame, 
eafily rolled the pillar along. It is by a fimilar mechanifm, 
that we fmooth our terraces, the gravel walks of our gar¬ 
dens, Sec. We know not the date of the building of this 
temple; we only know that it was burnt by Heroflratus, 
on the night wdien Alexander was born, in the year be¬ 
fore Chrilt 356. Metagenes, alfo, the fon of Ctefiphon, 
and who lucceeded his father in continuing the building, 
having to tranfport to Ephefus the ftones which were to 
form the architraves of the temple, fattened thefe ftones 
between two wheels of twelve feet diameter, which, from 
their proximity, formed as it were but one cylinder. 
In the theory of mechanics the ancients were not fa 
fuccefsful. We fee by fome of the writings of Ariftotle, 
(B.C. 320.) that even he had only confufed or erroneous 
notions concerning the nature of equilibrium and motion 
and of courfe all his predeceffors mult have been ftill 
more deficient. In his 28th mechanical queltion he has 
given foine vague obfervations on the force of impulfe, 
tending to point out the difference between impulfe and 
preffure. He maintained that there cannot be two circu¬ 
lar motions oppofife to one another; that heavy bodies 
defeended to the centre of the univerfe, and that the velo¬ 
cities of their defeent were proportional to their weights. 
The notions of Ariftotle, however, were fo confuted 
and erroneous, that the honour of laying the foundation 
of theoretical mechanics is exclufively due to the cele¬ 
brated Archimedes. This great mathematician, in his 
book of Equiponderants, confiders a balance fupported 
on a fulcrum, and having a weight in each fcale ; and, 
taking as a fundamental principle, that, when the two 
arms of the balance are equal, the two weights fuppofed 
to be in equilibrio are alio of neceflity equal, he fnows 
that, if one of the arms be increafed, the weight applied 
to it mull be proportionally diminifhed. Hence he de¬ 
duces the general conclulion, that two weights fufpended 
to the arms of a balance of unequal length, and remain¬ 
ing in equilibrio, mult be reciprocally proportional to the 
arms of the balance; and this is the firlt trace any-where 
to be met with of any theoretical invettigation of mecha¬ 
nical fcience. Archimedes alfo farther oblerved, that the 
two weights exert the fame preffure on the fulcrum of the 
balance as if they were directly applied to it; and he af¬ 
terwards extended the lame idea to two other weights fuf¬ 
pended from other points of the balance, then to two others, 
and fo on ; and hence, Itep by Itep, advanced towards the 
general idea of the centre of gravity, a point which he 
proved to belong to every afiemblage of fmall bodies, and 
confequently to every large body, which might be confi- 
dered as formed of fuch an afiemblage. This theory he 
applied to particular caies, and determined the fituation of 
the centre of gravity in the parallelogram, triangle, trape¬ 
zium, parabola, parabolic trapezium. See. See. To him 
we are alfo indebted for the theory of the inclined plane, 
the pulley, the lerevv, and the wedge. Hence he is re- 
prefented in our Frontifpiece furrounded by thefe em¬ 
blems of the mechanical powers. It appears alfo from 
Plutarch and other ancient authors, that various machines 
which have not reached our times were invented by this 
philofopher. The military engines w hich he employed in 
the fiege of Syracufe again ft thofe of the Roman engineer 
Appius, are laid to have dilplayed the greatelt mechanical 
genius, and to have retarded the capture of his native city. 
3 Among. 
