Ancient Egyptian Sundials

Description

The Egyptians divided the day into two cycles of 12 hours each and conceived the modern 365-day, 12 month calendar by adding five days to the Babylonian 360-day calendar. The ancient Egyptian civil calendar had three season: 1) Akhet (Flooding); 2) Peret (Growing or Sowing); and 3) Shemu (Harvest). Each season had four months with 30 days. The additional five days were tacked onto the end of Harvest and set aside for feasting during the annual flooding of the Nile.

Text and illustrations of the time suggest that the Merkhet was used to mark time at night by noting when particular stars sank below a horizon line. Some design features of the Merkhets discovered, and inscriptions or markings on them, suggest that they may also have been used as Shadow Clocks or Sundials.

Sunrise at the Summer Solstice of the time would have been at around 6am and so Noon (when the sun is directly overhead) would have been the 6th hour of the day. A Merkhet would need to be oriented to the East for the morning hours and West after Midday. A hand-held Merkhet would also have to be held horizontal. To achieve this, each Merkhet discovered has a small vertical groove at one end and this could have been use to guide the built-in Plum Bob.

A more conventional sundial dating to the 13th century B.C. and considered one of the oldest Egyptian sundials, was discovered in Egypt's Valley of the Kings, the burial place of rulers from Egypt's New Kingdom period (around 1550 B.C. to 1070 B.C.). The sundial is made of a flattened piece of limestone, called an Ostracon, with a black semicircle divided into 12 sections drawn on top. Small dots in the middle of each of the 12 sections, which are about 15 degrees apart, may have served to give more precise times. A dent in the centre of the Ostracon probably marks where a metal or wooden bolt was inserted to cast a shadow and reveal the time of day.

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• Structures and Frames can also be modelled using the Construction Kits listed in the Truss Bridges and Looking at Bridges articles.

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Junior Hacksaw	Clamp-on Hobby Vice	Stripwood	Balsa Wood	Medium card coloured	Thick card coloured	Cutting Mat	10mm Squared Paper	PVA glue	Glue Gun	Bamboo Flower Sticks

Notes:

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