Syracuse, Sicily Archives - Kotsanas Museum

The hydraulic clock of Archimedes

admino — Tue, 09 Apr 2024 10:12:39 +0000

It was a complex hydraulic clock with many automatically moving objects. It consisted of the central storage container which supplied the water. The water went through a smaller container which ensured the stability of the water level (with a conical valve on a float), leading to the outflow nozzle. The supply of the flow was regulated depending on the date, turning the nozzle on a calibrated semicircular disc (so that the hypsometric difference of the nozzle outflow hole and the level of water were altered, consequently, altering the time duration of the hour on the particular day). On the two columns of its façade, two moving rings (and two statuettes) indicated the hours that had been covered and the hours which remained respectively. On each hour, the pupils of the human eyes on a mask changed colour and a spherule fell into another container from the automatic opening of a crow’s beak, with a bang. Simultaneously, the water fell into a volumetric container which, on the hour, was automatically reversed and two small snakes slid towards the birds on the tree that cried out frightened.

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The planetarium of Archimedes

admino — Tue, 09 Apr 2024 10:11:34 +0000

This is a remarkable device which simulates automatically the complex movements of the sun, the moon and the planets known in antiquity, as they appear from any point on earth. It constitutes the most complex mechanism of antiquity. It was a remarkable invention as attested by the relevant reports of ancient sources. According to Cicero (1st c. A.D.), it was the only piece of the spoils that general Marcellus kept for himself after the fall of Syracuse. Suggested reconstruction: With every manual turn of the sphere, the central inner disc rotates isochronously through suitable cogwheels, having a transmission ratio 1:365,25 (3651/4), which was the assumed year duration at the time. Going further, the differing periodicity of the above celestial bodies is achieved with astonishing accuracy through a complex system of cogwheels, as well as the acceleration, deceleration and reverse movement. The sun and its inner planets (Mercury and Aphrodite-Venus), according to the geocentric system, are equipped with a suitable arrangement of cogwheels and jointed bars with slots, to accelerate their apparent movements (angular velocities and bidirectional movements) perfoming a full rotation throughout the year. The outer planets (Mars, Jupiter and Cronus-Saturn), on the contrary, carry a separate pair of eccentric cogwheels with a brilliant pin and slot system for their periodic (2 years and 10 months, 12 years and 30 years respectively) and bidirectional movements. The moon carries the cog-wheel arrangement corresponding to the mechanism of Antikythera, in order to effect its periodicity (27 and 1/3 days) and angular velocity. Its phases are shown through its simultaneous rotation around its axis, via a pair of vertical cogwheels and a leather string inside its supporting tubelet.

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The steam canon of Archimedes

admino — Tue, 09 Apr 2024 10:11:50 +0000

It was acannon that functioned with steam. It consisted of a cylindrical metal boiler which was connected to a closed container of water with a valve. The boiler at the open utmost end had an incorporated wooden barrel in which the launch stone ball was placed. The barrel was blocked with one wooden beam that was secured with two struts. When the boiler acquired the appropriate temperature with the fire, the valve was opened, the water poured into the boiler, evaporated rapidly, the wooden beam broke and the ball was launched. The range of the ball was regulated by the inclination of the weapon and the selected resistance of the wooden beam. The first redesigning of the steam cannon of Archimedes was made by Leonardo da Vinci, which was named “architronito” from the words Archimedes and “titrosko” (=injure).

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The windlass (“baroulkos”) of Archimedes

admino — Tue, 09 Apr 2024 10:10:13 +0000

It was a mechanism which consisted of co-operating worm gears (endless screws) and gearwheels inside a box used for the elevation or the drawing of heavy loads with the application of only minimal power. The mechanism is described in detail by Heron. However, it was invented by Archimedes who, with a similar mechanism, launched a giant ship with the power of one hand. Extolling the endless possibilities with the continuous increase in the number of gears and worm gears, he said: “Give me a place to stand and I can move the Earth”. According to Heron, for the real reduction of the needed traction force of a load by 1/200, the gearwheel ratio required is 1:5:5:5:8/5 (theoretically capable of achieving this purpose). While greater force reduction, by means of worm gear and crank, is necessary for the overriding of increased friction.

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