The Hispanic Society of America possesses a good example of Fortin’s work (Fig. 129), this being an armillary sphere, having at the common center of its system of circles a terrestrial globe about 5 cm. in diameter. It is without date, but probably was constructed about the year 1780. In the South Pacific within a cartouch is the inscription “A Paris chez le Sr. Fortin. Rue de la Harpe.” This example is 41 cm. in height, having a graduated horizon circle 31 cm. in diameter, supported on a turned wooden base by four arms or quadrants. The terrestrial globe map of twelve gores is much darkened with age but gives in good outline the several continents with a few geographical names. Its armillae are of pasteboard, consisting of a supporting meridian circle within which the several celestial circles can be revolved on the extended polar axis of the terrestrial globe. These celestial circles represent the zodiac, on the surface of which are given the names of the several zodiacal constellations and the names of the months, the meridian circles, the tropics, the equator, the two polar circles with an hour circle at the north pole, all of these being so attached as not to permit of independent motion. Attached to one of the meridian circles is a device for representing eclipses, the one of the sun and the other of the moon. [Illustration: Fig. 129. Armillary Sphere of Jean Fortin, 1780.] George Adams, the elder (fl. 1760), maker of mathematical instruments and optician to His Majesty George III of England, won great distinction for himself as a maker of terrestrial and celestial globes, and as a writer on geographical and astronomical subjects. With him in his work were associated his sons George (1750-1795) and Dudley, to whom, after the death of the brother, fell the management of the business. We know of Dudley’s success in his work, which he must have carried on well into the first quarter of the nineteenth century, though we know neither the date of his birth nor of his death. In the year 1766 the elder Adams issued the first edition of a very useful work on globes, including a consideration of their construction and their uses.[174] In the year 1810 appeared the thirtieth edition of this work, with a preface and additions by the son, Dudley. The title of the work suggests that the first issue was prepared as a description of globes which the author had just put upon the market, but globes of his bearing a date so early seem to be unknown. None have been located which appear to have been issued earlier than the year 1772, after which time we know there were repeated issues signed either “G. Adams” or “D. Adams.” A pair of the date 1782 may be found in the Museo Astronomico of Rome. These appear to be in a fair state of preservation (Fig. 130). Each has a diameter of about 46 cm., being furnished with a graduated brass meridian circle within which the sphere revolves, a graduated horizon circle of wood, having pasted