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Inventory no. 49861 - Former Display Label

19
Part of an Egyptian ASTROLABE
681 A.H. = 1282-3 A.D.

Signed, on the back of the kursĂ®, 'The servant yearning for [his Lord or Allah] the Forgiving and Merciful, Hasan {ain}Ali in Egypt, made it in Cairo the protected, in the year six hundred and eighty-one'. Silvered brass. It appears to be the back-plate from an umm of the type made by rivetting a separately made limb to a brass-plate, instead of casting the whole umm in one piece.

The side of the plate shown above (which would have been the interior of the umm) is engraved with concentric circles crossed by diametrical lines marked 'north', 'south', 'east' and 'west'. To two of the 5 holes (probably originally made for rivets fixing the limb) are now rivetted silver fishes (? as indices).

At the edge of the upper-half of the back (shown above) is engraved a scale of degrees marked with unusual numerical ciphers. The quadrant on the left is engraved as a sine graph; that on the right is similarly divided vertically and has almucantars for every 5th degree. In the lower half are two tables, that on the left was used to 'know the degree of the sun' and that on the right is a table of the Coptic months, showing when the 'sun takes up his abode' in each of the 12 divisions of the zodiac.

[IC 107]
Lewis Evans Collection

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