Exhibits Archive - Kotsanas Museum

Aeneas cryptographic disc

admino — Tue, 09 Apr 2024 10:10:53 +0000

It was a disc with 24 holes (one for each letter of the alphabet) on the periphery, one in the centre and one more defining the letter “A”. The sender formed the message by passing a thin thread through the holes of the relevant letters and the receiver read it by removing the thread and noting the letters from right to left.

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Apollo’s “kithara” (guitar)

admino — Tue, 09 Apr 2024 10:09:16 +0000

It was a majestic stringed instrument with a powerful and deep sound which required particular virtuosity and accompanied the song (“kitharodeia”) in music competitions and other important public events. It consisted of a large trapezoid wooden soundbox with two incorporated symmetrical solid curved arms that were connected to two upper arms. The connecting flexible curlicues (a complicated adjusting mechanism of curved metal strips, horns, etc). The elasticity of the arms allowed them imperceptible vertical motion thus creating a distinct wave-like resonance. The two (possibly cam rotating) prominent spirals on the upper arms, which supported the crossbar, helped in releasing and adjustment of tension of the crossbar (and the strings) so that the organ is at rest or playing position. Also, the sliding balance bronze weights of the crossbar helped in its tunning. The bridge (“magadion”) which was sometimes also complicated with a series of incorporated tension levers gave the possibility of alternative, equal in number, note production. The player held the kithara almost upright against the left side of his body (bent slightly inward, often with the help of a sling) and the left-hand fingers pressed or plucked its strings (usually 7) while the right hand struck them with the “plectrum”. Terpander (who established the 7th string), Stesichorus, Amiveas of Athens, Aristonicus of Argos (who introduced solo playing – unaccompanied by song), Agelaus of Tegea and Lysander of Sicyon are only some of the numerous famous kitharodes.

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Archimede’s burning mirrors

admino — Tue, 09 Apr 2024 10:10:29 +0000

It is a hypothetical reconstruction of the renowned burning mirrors of Archimedes. Several ancient Greek writers, including Archimedes, had written books “on burning mirrors”, but none of them have survived. Some medieval writers describe the burning of the Roman fleet by Archimedes using such mirrors, though it is not mentioned by ancient writers. One of them, Ioannis Tzetzes (1110-1180 A.D.) describes the burning of ships, from a distance within an arrow’s range, with the help of large hexagonal mirrors invented by Archimedes. He also mentions that these large hexagonal mirrors consisted of smaller mirrors, adjusted to the main one by means of blades and joints. This remarkable description indicates an adjustable mirror with variable focus. Although the alleged burning of ships is considered a myth, it would be quite possible to set moving ships on fire using large mirrors with adjustable focus. The reconstructed mirrors, using the right placement of pulleys (or gears alternatively) and the easy rotation of a single rope, follow an adjustable parabolic path, constantly changing its focus, according to the operator’s will. Archimedes had all the necessary knowledge in Mathematics and Engineering, as well as the technological skills in order to construct them.

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Level horizontal sundial (Eudoxus’ “Arachne” and “Pelekinos” of Patrokles)

admino — Tue, 09 Apr 2024 10:11:19 +0000

A grid with 11 engraved hour lines and three curves indicated, with the help of the shadow trace from the vertical gnomon edge (oriented to the South) 10 out of the 12 unequal (depending on the season) day hours. The closest curve to the gnomon indicated the course of the Sun’s shadow at the summer solstice, the most distant at the winter solstice and the middle one (straight line) at the equinoxes. The entire line grid was named “Analemma” and sometimes it included 4 more curves that defined the Sun shade’s orbit for the entry of the remaining zodiacs (months). Later on, an oblique gnomon was used with inclination equal to the latitude of the place (φ) so that only the orientation of its shadow for the indication of the hours was enough.

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The “aeolosphere” of Heron

admino — Tue, 09 Apr 2024 10:08:35 +0000

It is the precursor of the steam-turbine which, with the addition of a pulley, would have led the Hellenistic Era (had it not been interrupted by the political, economical and social factors) to the Industrial Revolution with unforeseeable consequences for humanity. It consisted of a sphere (with two curved nozzles) which rested on the curved ends of two pipes connected to the top of an airtight boiler. When the water in the boiler was heated, it turned into steam. Then, it entered the sphere and came out with speed from the two nozzles forcing the opposite continuous rotation of the sphere.

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The “anaphoric” clock

admino — Tue, 09 Apr 2024 10:10:05 +0000

It was a brilliant hydraulic clock which indicated, with accuracy, the 365 different hours of the year. A cam disc – on which a drawing represented
the sky and the zodiac cycle – rotated behind a bronze grid. The grid consisted of 7 homocentric circles defining the month intervals and 24 curved rods defining the hours according to the “hour – month” diagram (“analemma”). The rotation of the disc was achieved through a pulley and a flexible chain
with a counterweight and a weight-float which was lowered or lifted through the isochronous (=equal time) descent or ascent of the water level. This isochronous descent or ascent was ensured by the isochronous water outflow
through a self-regulated controller of the constant level of the Ktesibios type.
Every day a pointer was placed successively on the corresponding one of the 365 holes of the disc periphery, which defined the days of the zodiac year, and marked the 12-day and 12-night non-isochronous hours according to the season.

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The “Greek” watermill

admino — Tue, 09 Apr 2024 10:09:47 +0000

It was a water-powered mill for grinding grain which continues identically in use until today. According to Strabon, it was first used in Kavira by the king of Pontus Mithradates VI Eupator. It was particularly suitable for the hilly and mountainous regions of Greece and Asia Minor since it was capable of functioning with small quantities of water that were moved, however, at great speed. It constitutes the predecessor of the water turbine. It consisted of one horizontal impeller, a vertical axle and two horizontal millstones. The axle penetrated the lower millstone and was connected via metal connections to the (perforated at its centre) upper millstone. The water moved the impeller and the axle transmitted the rotation to the upper millstone. The fruit from the funnel fell into the opening of the rotating millstone, was ground between the two millstones and came out circumferentially because of the centrifugal force.
The funnel was provided with a fruit supply regulator, depending on the speed of the rotation.

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The “hysplex”

admino — Tue, 09 Apr 2024 10:09:55 +0000

It was a starting mechanism used in Ancient Greece during the Olympics and other athletic competitions in order to prevent the false start of the athletes. It consisted of two vertical poles fixed to the starting line, bearing two horizontal ropes (one at the height of the knees and the other at the height of the athletes’ abdomen). When the referee pulled the rope of ring latches that released the poles, they fell with momentum on the ground –because of the force of the twisted string at the base– thus permitting the start of the race.

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The “lyra” (lyre)

admino — Tue, 09 Apr 2024 10:11:42 +0000

It was an ancient stringed instrument (invented by Hermes) which was already popular and widespread in Mycenaean times. Closely associated with the worship of Apollo and a means of education for young persons, it constituted, along with the “aulos” (clarinet), the national (and often “competitive”) musical instrument of the Greeks. In its earliest form (“chelys”), it consisted of the soundbox (with a palpitating membrane from the skin of an ox or kid stretched over the open side of a concave tortoise shell), the two arms (made of goat horns or two similar curved wooden rods) and the crossbar (a cylindrical piece of wood connected across to the arms). The, equal in length, strings (from 3 to 12) were primarily made of hemp or flax and later of twisted animal (e.g. sheep) gut or sinew. The strings were secured to the brace (tailpiece), passed over the bridge (“magadion”) and tightened on the crossbar. The adjustment of tension (tuning) was initially achieved with the help of a thong, later with a free or fixed slip of wood, but also wooden tuning pegs (“kollavoi”). The player held the instrument against the left side of his body (often with the help of a sling). The left-hand fingers pressed or plucked the strings while the right hand struck the strings with a “plectrum”. The “plectrum”, which was attached by a cord, consisted of a curved handle and a pointed blade of ivory, horn or bone.

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The “papyrella”

admino — Tue, 09 Apr 2024 10:09:32 +0000

It was a primitive oared boat that consisted of many fascicles of thin cane (“papyruses”) tied together with ropes. It had the form of a ship that could sail from both sides and ensured great stability, excellent floatability and allowed the transport of merchandise. Its presence in Greece is indirectly denoted by the proven commercial transactions of the residents of the Aegean Sea (e.g. transportation of obsidian from the island of Milos in the cave of Franchthi in Argolida) from 9th millenium B.C. and directly from its survival in our days in Corfu. The archaeologist, Harris Tzalas, proved, by experimenting, the possibility of realising, in a 6- metre papyrella with 6 oarsmen, a multi-day voyage of 75 nautical miles from Sounio to Milos in the open sea.

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