[179] Fiorini, op. cit., p. 441. [180] Dictionary of National Biography, “Cary, William”; Wolf, Geschichte der Astronomie, pp. 562, 563. Chapter XIV The Technic of Globe Construction--Materials and Methods General problems to be met.--Development from the simple armilla to the complex sphere.--The references of Ptolemy, Leontius Mechanicus, Alfonso.--Behaim’s leadership in practical globe making.--Materials employed.--Experiments in map projection.--The beginning and rapid development of globe-gore construction.--Various examples of early gore maps.--Equatorial polar and ecliptic polar mountings.--Special features of celestial globe maps.--Globe mountings.--Varying sizes of globes.--The uses of globes.--Moon globes and planetariums. In this concluding chapter it is not proposed to consider in detail the technical features of globe construction, as these features have presented themselves in the long period which has been under review; the rather to give, somewhat in the nature of a summary, a general word as to the development of the simple armilla of the ancients, “in continued succession, receiving ripeness and perfection” in such celestial spheres as were those of Mohammed ben Helal, of Tycho, of Hondius, or of Blaeu; into the terrestrial spheres of Schöner, of Mercator, of Greuter, or of Coronelli. We have seen that during these years there were problems mechanical, mathematical, and artistic continually arising, in the solution of which talent of a high order was often exhibited; problems having to do with the kind of material to be employed, with the shaping and the graduation of the rings or circles, with the construction of the supporting bases which entered into the completed product, with the engraving of the map on the surface of the metal sphere, or with the designing and the engraving of the plates for the printing of the map to be used in covering the prepared ball, and the fitting of the same to its curved surface. [Illustration: Fig. 133. Astrolabe.] The principal astronomical instrument employed by such ancient astronomers as Eudoxus, Timocharis, and Hipparchus appears to have been at first but a single metal ring, perhaps of brass. At any rate their instruments must have been exceedingly simple, perhaps the simplest form of the astrolabe (Fig. 133), yet they sufficed as aids in the solution of such astronomical problems as suggested themselves in that early day. The addition of a second ring to the simple instrument gave further aid to the observer in his efforts to determine the declination and the right ascension of any of the heavenly bodies. These rings came to be considered, the first as a celestial meridian circle, the second as a celestial horizon circle, and in the passing years others were added to represent the ecliptic, the colures, the tropics, the polar circles, and the orbits of the several planets, until we have the fully developed armillary sphere of a Vopel or a Santucci.[181]