Rare Islamic Astrolabe, probably late 18th/early 19th Century

Probably Persia or Lahore. Brass mater, rete, four engraved plates, alidade and pin in the form of a curved dagger, on brass suspension ring, diameter 3 ½ in. x ht. 4 3/8 x dp. 2/8 in. (8,9 x 11 x 0,7 cm). The throne decorated with sunflower and foliage; the limb divided into 360˚, marked at intervals of 5˚ with Abjad numerals; mater with geographical gazetteer of two circular scales with engraved coordinates of 38 locations, including Baghdad, Tabriz, Isfahan and Shiraz in the inner and Sistan, Kashmir and Multan in the outer; rete with ecliptic ring and the positions of 26 stars, the star pointers formed as bird heads; the reverse with engraved tables and scales showing planets, zodiacal houses and mansions of the moon; the four plates with engraved degrees of latitude.

布雷克拍品等级是为了方便竞买人判断拍卖品的成色而设置的。布雷克等级用1到6级来标注外观和功能的成色，(从非常好到非常差)。 在目录图册里用括号里的2个数字来表示，前一个数字表示外观成色的级别，后一个数字表示功能成色的级别。如(3/2)表示外观成色是3(满意的)，功能成色2(好)。 成色 定义参照下列标准： 1 - 非常好 (未使用过，没有使用痕迹) 2 - 好 (新，极少的使用痕迹) 3 - 满意的 (普通的使用痕迹) 4 - 及格的 (明显的使用痕迹，某个非主要部件是后配的) 5 - 有缺陷的 (极明显的使用痕迹, 某个主要部件是后配的，功能上有缺陷，需要修理) 6 - 非常差 (严重破损, 缺少重要部件)