+--------------------------------------------------------------+ | This e-text includes characters that require UTF-8 | | (Unicode) file encoding: | | | | ḍ, ā, ḥ, ȧ, ī | | | | If any of these characters do not display properly--in | | particular, if the dots do not appear under the letters | | make sure your text reader’s “character set” or “file | | encoding” is set to Unicode (UTF-8). You may also need to | | change the default font. Depending on available fonts, some | | tables may not line up vertically. | +--------------------------------------------------------------+ CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY: PAPER 6 ON THE ORIGIN OF CLOCKWORK, PERPETUAL MOTION DEVICES AND THE COMPASS _Derek J. de Solla Price_ POWER AND MOTION GEARING 83 MECHANICAL CLOCKS 84 MECHANIZED ASTRONOMICAL MODELS 88 PERPETUAL MOTION AND THE CLOCK BEFORE DE DONDI 108 THE MAGNETIC COMPASS AS A FELLOW-TRAVELER FROM CHINA 110 _ON THE ORIGIN OF CLOCKWORK,_ _PERPETUAL MOTION DEVICES_ _AND THE COMPASS_ _By Derek J. de Solla Price_ _Ancestor of the mechanical clock has been thought by some to be the sundial. Actually these devices represent two different approaches to the problem of time-keeping. True ancestor of the clock is to be found among the highly complex astronomical machines which man has been building since Hellenic times to illustrate the relative motions of the heavenly bodies._ _This study--its findings will be used in preparing the Museum's new hall on the history of time-keeping--traces this ancestry back through 2,000 years of history on three continents._ THE AUTHOR: _Derek J. de Solla Price wrote this paper while serving as consultant to the Museum of History and Technology of the Smithsonian Institution's United States National Museum._ In each successive age this construction, having become lost, is, by the Sun's favour, again revealed to some one or other at his pleasure. (_Sūrya Siddhānta_, ed. Burgess, xiii, 18-19.)