ON THE ORIGIN OF CLOCKWORK, 



PERPETUAL MOTION DEVICES 



AND THE COMPASS 



By Derek J. cle Solla Price 



Ancestor of the mechanical clock hiis bei'ii thoi/gl.it 

 by some to be the sundial. Actually these devices 

 represent two different approaches to the problem of 

 timekeeping. 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 netv hall on the history of timekeeping — 

 traces this ancestry back through 2,000 years of history 

 on three continents. 



The Author; Derek J. de Solla Price ivrote this 

 paper while serving as consultant to the Museum of 

 History and Technology of the Smithsonian Institu- 

 tion s United States National Museum. 



In each successive age this coiistrucdon, 

 having become lost, is, by the Sun's favour, 

 again revealed to some one or other at his 

 pleasure. (Surj/a Siddhanta. cd. Burgess, xiii, 

 18-19.) 



THK HISTORIES of the mechanical clock and the 

 magnetic compass must be accounted amongst 

 the most tortured of all our efforts to understand the 

 origins of man's important inxentions. Ignorance 

 has too often been replaced by conjecture, and con- 

 jecture by misquotation and the false authority 

 of "common knowledge" engendered by the repeti- 

 tion of legendary histories from one generation of 

 textbooks to the next. In what follows, I can only 

 hope that the adding of a strong new trail and the 

 eradication of several false and weaker ones will lead 

 us nearer to a balanced and integrated understanding 

 of medieval invention and the inierciihural trans- 

 mission of ideas. 



For the mechanical chxk, perhaps the greatest 

 hindrance has been its treatment within a self- 

 contained "history of time measurement" in which 

 sundials, water-clocks and similar de\'ices assume 

 the natiual role of ancestors to the weight-driven 

 escapement clock in the early 14th century.' This 

 view must presume that a generally sophisticated 

 know ledge of gearing antedates the in\eniion of the 

 clock and extends back to the Classical period of 

 Hero and \'itru\ius and such authors well-known 

 for their mechanical ingenuities. 



Furthermore, even if one adinits the use of clocklike 

 gearing before the existence of the clock, it is still 



' This traditional view is expressed by almost every history 

 of horology. An ultimate source for many of those has been 

 the following two classic treatments: J. Beckmann, .1 hislory 

 of invenlions and discoveries, -Ith ed., London, 1846, vol. 1, pp. 

 340 ff. A. P. Usher, A history oj mechanical inventions, 2nd ed.. 

 Harvard University Press. 1954, pp. 191 ff., 304 ff. 



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BULLETIN 218: CONTRIBUTIONS FROM THF MUSEUM OF HISTORY AND TECHNOLOGY 



