It appears that Archimedes showed his relative Hiero II., King of Syracuse, some wonderful examples of the way in which immense weights could be moved by a combination of levers.
Hiero, being greatly impressed by these experiments, entreated Archimedes temporarily to employ his genius in designing articles of practical use, with the result that the scientist constructed for the king all manner of engines suitable for siege warfare.
Though Hiero did not require the machines, his reign being a peaceful one, they proved of great value shortly after his death when Syracuse was besieged by the Romans under Marcellus, 214–212 B.C.
On this occasion Archimedes directed the working of the engines he had made some years previously for Hiero.
Plutarch writes: ‘And in truth all the rest of the Syracusans were no more than the body in the batteries of Archimedes, whilst he was the informing soul. All other weapons lay idle and unemployed, his were the only offensive and defensive arms of the city.’
When the Romans appeared before Syracuse, its citizens were filled with terror, for they imagined they could not possibly defend themselves against so numerous and fierce an enemy.
But, Plutarch tells us, ‘Archimedes soon began to play his engines upon the Romans and their ships, and shot against them stones of such an enormous size and with so incredible a noise and velocity that nothing could stand before them. The stones overturned and crushed whatever came in their way, and spread terrible disorder through the Roman ranks. As for the machine which Marcellus brought upon several galleys fastened together, called sambuca[27] from its resemblance to the musical instrument of that name; whilst it was yet at a considerable distance, Archimedes discharged at it a stone of ten talents’ weight and, after that, a second stone and then a third one, all of which striking it with an amazing noise and force completely shattered it.[28]
[27] Sambuca. A stringed instrument with cords of different lengths like a harp. The machine which Marcellus brought to Syracuse was designed to lift his soldiers—in small parties at a time and in quick succession—over the battlements of the town, so that when their numbers inside it were sufficient they might open its gates to the besiegers. The soldiers were intended to be hoisted on a platform, worked up and down by ropes and winches. As the machine was likened to a harp, it is probable it had a huge curved wooden arm fixed in an erect position and of the same shape as the modern crane used for loading vessels. If the arm of the sambuca had been straight like a mast, it could not have swung its load of men over a wall. Its further resemblance to a harp would be suggested by the ropes which were employed for lifting the platform to the summit of the arm, these doubtless being fixed from the top to the foot of the engine.
[28] It is, I consider, impossible that Archimedes, however marvellous the power of his engines, was able to project a stone of ten Roman talents or nearly 600 lbs. in weight, to a considerable distance! Plutarch probably refers to the talent of Sicily, which weighed about 10 lbs. A stone of ten Sicilian talents, or say 100 lbs., could have been thrown by a catapult of great strength and size.
Though the trebuchet cast stones of from 200 lbs. to 300 lbs. and more, this weapon was not invented till long after the time of Archimedes.