It has been previously noted that the so-called globe of Archimedes may have been a sort of planetarium, and that during the middle ages such instruments were constructed and employed in astronomical instruction. None, however, have come down to us out of those early years. Astronomers of the seventeenth and eighteenth centuries, as we know, made frequent use of planetariums, such for example as were constructed by the Dutch astronomer, Christiaan Haygens (1629-1695) for the illustration of planetary motion according to the Copernican system. Each of the planets was represented in his machine by a small ball, attached to an arm, which could be made to move through an orbit around the sun. In the more complicated machines the several planetary moons, such as the moons of Jupiter, were represented and were made to perform their proper motions. [Illustration: Fig. 141. Celestial Globe Gores by Johannes Oterschaden, ca. 1675.] [Illustration: Fig. 142. Engraved Sections for Globe Horizon Circle by Johannes Oterschaden, ca. 1675.] In the eighteenth century the instrument maker, George Graham (1675-1751), constructed a complicated planetarium, in honor of Charles Boyle, Earl of Orrery (1676-1731), which he called an orrery. His machines, varying much in the character of construction, were especially popular in the eighteenth century. The nineteenth century saw them frequently in use for purposes of instruction and the regret may well be expressed that for serious purposes they seem to have lost favor. [Illustration: Fig. 143. The Orrery.] NOTES [181] See Fig. 56, I, 116. [182] Compare for example Figs. 8 and 89. [183] Consult the ‘Fihrist’ referred to in Chap. III, n. 4. [184] Note such examples as the globe of Robertus de Bailly, I, 108, the Lenox globe, I, 72, the Nancy globe, I, 102, and the Morgan globe in the Metropolitan Museum, I, 200. [185] See Fig. 3. [186] See Fig. 43. [187] See Apianus’ Cosmographicus liber. [188] As for example the World map of Mercator of the year 1538, an original copy of which may be found in the New York Public Library, also a copy in the Library of The American Geographical Society. [189] D’Avezac, M. A. P. Coup d’oeil historique sur la projection des cartes de géographie. (In: Bulletin de la Société de Géographie de Paris. Paris, 1863, pp. 274 ff.); Breusing, A. Das Verebnen der Kugeloberfläche. Leipzig, 1892; Zondervan, H. Allgemeine Kartenkunde. Leipzig, 1891; Fiorini, M. Le projezioni delle carte geografiche. Bologna, 1881. The literature relative to map projection is very extensive. [190] Fiorini. Sfere terrestri e celesti. pp. 93-102. [191] See Fig. 32. [192] See Fig. 40. [193] Dürer, A. Underweysung der Mesung mit dem Zirkel und Richtscheyd, in Linien ebnen und ganzen Corporen. Nürnberg, 1525. [194] Buchlein, pp. 5 ff.