THE ENGINES OF ARCHIMEDES FROM THE LIFE OF MARCELLUS

Marcellus now moved with his whole army to Syracuse, and, camping near

the wall, proceeded to attack the city both by land and by sea. The land

forces were conducted by Appius: Marcellus, with sixty galleys, each

with five rows of oars, furnished with all sorts of arms and missiles,

and a huge bridge of planks laid upon eight ships chained together, upon

which was carried the engine to cast stones and darts, assaulted the

walls, relying on the abundance and magnificence of his preparations,

and on his own previous glory; all which, however, were, it would seem,

but trifles for Archimedes and his machines.

These machines he had designed and contrived, not as matters of any

importance, but as mere amusements in geometry; in compliance with King

Hiero's desire and request, some little time before, that he should

reduce to practice some part of his admirable speculations in science,

and by accommodating the theoretical truth to sensation and ordinary

use, bring it more within the appreciation of people in general. Eudoxus

and Archytas had been the originators of this far-famed and highly

prized art of mechanics, which they employed as an elegant illustration

of geometrical truths, and as a means of sustaining experimentally, to

the satisfaction of the senses, conclusions too intricate for proof

by words and diagrams. As, for example, to solve the problem, so often

required in constructing geometrical figures, given the two extreme, to

find the two mean lines of a proportion, both these mathematicians had

recourse to the aid of instruments, adapting to their purpose certain

curves and sections of lines. (The 'mesolabes or mesalabium, was the

name by which this instrument was commonly known.) But what with Plato's

indignation at it, and his invectives against it as the mere corruption

and annihilation of the one good of geometry,--which was thus shamefully

turning its back upon the unembodied objects of pure intelligence to

recur to sensation, and to ask help (not to be obtained without haste

subservience and depravation) from matter; so it was that mechanics came

to be separated from geometry, and, being repudiated and neglected by

philosophers, took its place as a military art. Archimedes, however,

in writing to King Hiero, whose friend and near relation he was, had

stated, that given the force, any weight might be moved, and even

boasted, we are told, relying on the strength of demonstration, that if

there were another earth, by going into it he could remove this. Hiero

being struck with amazement at this, and entreating him to make good

this problem by actual experiment, and show some great weight moved by

a small engine, he fixed accordingly upon a ship of burden out of the

king's arsenal, which could not be drawn out of the dock without great

labor and many men; and, loading her with many passengers and a full

freight, sitting himself the while far off, with no great endeavor, but

only holding the head of the pulley in his hand and drawing the cord by

degrees, he drew the ship in a straight line, as smoothly and evenly as

if she had been in the sea. The king, astonished at this, and convinced

of the power of the art, prevailed upon Archimedes to make him engines

accommodated to all the purposes, offensive and defensive, of a siege.

These the king himself never made use of, because he spent almost

all his life in a profound quiet, and the highest influence. But

the apparatus was, in a most opportune time, ready at hand for the

Syracusans, and with it also the engineer himself.

When, therefore, the Romans assaulted the walls in two places at once,

fear and consternation stupefied the Syracusans, believing that nothing

was able to resist that violence and those forces. But when Archimedes

began to ply his engines, he at once shot against the land forces all

sorts of missile weapons, and immense masses of stone that came down

with incredible noise and violence, against which no man could stand;

for they knocked down those upon whom they fell, in heaps, breaking all

their ranks and files. In the mean time huge poles thrust out from the

walls over the ships, sunk some by the great weights which they let down

from on high upon them; others they lifted up into the air by an iron

hand or beak like a crane's beak, and, when they had drawn them up by

the prow, and set them on end upon the poop, they plunged them to the

bottom of the sea; or else the ships, drawn by engines within, and

whirled about, were dashed against steep rocks that stood jutting out

under the walls, with great destruction of the soldiers that were aboard

them. A ship was frequently lifted up to a great height in the air (a

dreadful thing to behold), and was rolled to and fro, and kept swinging,

until the mariners were all thrown out, when at length it was dashed

against the rocks, or let fall. In the meantime, Marcellus himself

brought up his engine upon the bridge of ships, which was called

"Sambuca," from some resemblance it had to an instrument of music, but

while it was as yet approaching the wall, there was discharged at it a

piece of rock of ten talents' weight, then a second and a third, which,

striking upon it with immense force and with a noise like thunder,

broke all its foundations to pieces, shook out all its fastenings, and

completely dislodged it from the bridge. So Marcellus, doubtful what

counsel to pursue, drew off his ships to a safer distance, and sounded a

retreat to his forces on land. They then took a resolution of coming

up under the walls, if it were possible, in the night; thinking that as

Archimedes used ropes stretched at length in playing his engines, the

soldiers would now be under the shot, and the darts would, for want of

sufficient distance to throw them, fly over their heads without effect.

But he, it appeared, had long before framed for such occasion engines

accommodated to any distance, and shorter weapons; and had made numerous

small openings in the walls, through which, with engines of a shorter

range, unexpected blows were inflicted on the assailants. Thus, when

they who thought to deceive the defenders came close up to the walls,

instantly a shower of darts and other missile weapons was again cast

upon them. And when stones came tumbling down perpendicularly upon their

heads, and, as it were, the whole wall shot out arrows at them, they

retired. And now, again, as they were going off, arrows and darts of

a longer range inflicted a great slaughter among them, and their ships

were driven one against another; while they themselves were not able

to retaliate in any way; for Archimedes had fixed most of his engines

immediately under the wall. The Romans, seeing that infinite mischiefs

overwhelmed them from no visible means, began to think they were

fighting with the gods.

Yet Marcellus escaped unhurt, and, deriding his own artificers

and engineers, exclaimed "What! Must we give up fighting with this

geometrical Briareus, who plays pitch and toss with our ships, and,

with the multitude of darts which he showers at a single moment upon us,

really outdoes the hundred-handed giants of mythology?" The rest of the

Syracusans were but the body of Archimedes' designs, one soul moving

and governing all; for, laying aside all other arms, with his alone they

infested the Romans, and protected themselves. In fine, when such terror

had seized upon the Romans, that, if they did but see a little rope or

a piece of wood from the wall, they instantly cried out, "There it is

again! Archimedes is about to let fly another engine at us," and turned

their backs and fled, Marcellus desisted from conflicts and assaults,

putting all his hope in a long siege. Yet Archimedes possessed so high a

spirit, so profound a soul, and such treasures of scientific knowledge,

that though these inventions had now obtained him the renown of more

than human sagacity, he yet would not deign to leave behind him any

commentary or writing on such subjects; but, repudiating as sordid and

ignoble the whole trade of engineering, and every sort of art that

lends itself to mere use and profit, he placed his whole affection and

ambition in those purer speculations where there can be no reference

to the vulgar needs of life; studies, the superiority of which to all

others is unquestioned, and in which the only doubt can be, whether

the beauty and grandeur of the subjects examined, or the precision and

cogency of the methods and means of proof, most deserve our admiration.

It is not possible to find in all geometry more difficult and intricate

questions, or more simple and lucid explanations. Some ascribe this to

his natural genius; while others think that incredible effort and toil

produced these apparently easy and unlabored results. No amount of

investigation of yours would succeed in attaining the proof, and yet,

once seen, you immediately believe you would have discovered it; by so

smooth and so rapid a path he leads you to the conclusion required. And

thus it ceases to be incredible that (as is commonly told of him), the

charm of his familiar and domestic Siren made him forget his food and

neglect his person, to such a degree that when he was occasionally

carried by absolute violence to bathe, or have his body anointed, he

used to trace geometrical figures in the ashes of the fire, and diagrams

in the oil on his body, being in a state of entire preoccupation, and,

in the truest sense, divinely possessed with his love and delight in

science. His discoveries were numerous and admirable; and he is said

to have requested his friends and relations that when he was dead, they

would place over his tomb a cylinder containing a sphere, inscribing it

with the ratio of three to two which the containing solid bears to the

contained.

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