In the year 1829 Dorn published a detailed description of an Arabic globe which had been deposited in the museum of the Asiatic Society of London (Fig. 13) by Sir John Malcolm.[65] It is of brass, has a diameter of 24 cm., and is furnished with a substantial mounting. The peculiar features of the figures which represent the several constellations suggest Persian workmanship. In the vicinity of the south pole is an inscription in Cufic characters, telling us that it was “Made by the most humble in the supreme god, Mohammed ben Helal, the astronomer of Monsul, in the year of the Hegira 674.” This year answers to the year 1275 of the Christian era, that is, it was constructed about the same time as the Borgian globe and that belonging to the Dresden collection, briefly described below. Forty-seven constellations are represented. On the horizon circle, in their respective places, we find engraved the words, “East,” “West,” “South,” “North.” [Illustration: Fig. 13. Northern Hemisphere of Globe by Mohammed ben Helal, 1275.] The Arabic globe, to be found in the Mathematical Salon of Dresden (Fig. 14), has proved to be one of much interest and scientific value to students of astronomy.[66] Bode, who described it in the year 1808, refers to its remarkably fine execution and to its Cufic inscriptions as being among the finest extant specimens of early Arabic writing. The sphere is of brass, having a diameter of 14 cm., and is composed of two parts, separable on the line of the ecliptic. It has a brass horizon circle, on which is engraved at the east the word “rising,” and at the west the word “setting.” It is not supplied with a movable meridian circle, but within the horizon circle, from north to south, and from east to west, there are two brass half circles, of the same diameter as the horizon circle and so adjusted as to form one piece with it. Through such an arrangement it is made possible to turn the globe in any desired direction, one half of it being at all times above the horizon. In addition to the above arrangement, there are two movable half circles, attached at the zenith point by a pivot. These half circles are graduated, and are movable, making it possible to find, by means of them, the declination and right ascension of any star. The base, which must be comparatively modern, consists of a circular plate, from which rise four turned support columns, attached at their upper extremities to the two half circles of brass, on which rests the horizon circle. [Illustration: Fig. 14. Globe of Mohammed ben Muwajed el Ordhi, 1279.]