Author
water damage
Publication Date
1270-1315 (CE, Gregorian)
Type
Book
Language
Arabic
Digital
Yes
Manuscript
Yes
Pages Count
1
Library
Qatar Digital Library
Library Asset ID
Or 9587, ff 30r-30v
Record ID
vdc_100023484928.0x000002
Library Location
British Library: Oriental Manuscripts
Date
1270-1315 (CE, Gregorian)
Notes
Fragment of a general introduction to the use of sundials. The text does not appear to be saved elsewhere. Only one folio of this treatise is preserved and the text is imperfect at the end. The text on the lower half of f. 30v is obscured by water damage, worm holes and repairs.
Beginnings (f. 30r, lines 2-7):
General work in making shading machines
Written by our Sheikh, the author of the previous ones, may God prolong his life
Assume the slab surface that...
We draw hour lines in it, a circle, ABC, D, and exit
In which diagonals A, C, and D intersect at right angles to a point E and because
Each point on the sphere can be assigned an azimuth and is a pole of a horizon circle
Ends (f. 30v, 14-21):
...and they are all in the position of the sun for the last hour
The day was the time (!) or the middle degree of the time (?) of the zodiac and it was circular
From the astronomy, for a time, an arc is supposed to be, and we emerge from the point, Ya, a straight line
Perpendicular to the line Z F, which is a line YB, and we separate the line Z like the line YB
From […] emerges a line parallel to the line E, which is a hand line that meets the circle
It is clear that [...] the height of the sun at that time
On [...] the finest Talal [...] is a bow with a hand
[...] The shadow
Erişim Koşulları
Unrestricted
Seçilmiş kaynakça
Casulleras, Josep 'Ibn al-Raqqām: Abū ʿAbd Allāh Muḥammad ibn Ibrāhīm ibn ʿAlī ibn Aḥmad ibn Yūsuf al-Mursī al-Andalusī al-Tūnisī al-Awsī ibn al-Raqqām' in
The Biographical Encyclopedia of Astronomers
, Thomas Hockey et al., eds., (New York: Springer, 2007) pp. 563-564
