chanical clocks has demonstrated certain peculiari- 

 ties most relevant to our present argument. 



THE EUROPEAN TRADITION 



If one is to establish a terminus ante quern for the ap- 

 pearance of the mechanical clock in Kurope, it would 

 appear that 1364 is a most reasonable date. At that 

 time we have the very full mechanical and historical 

 material concerning the horological masterpiece built 

 by Giovanni de Dondi of Padua," and probably 

 started as early as 1348. It might well be possible to 

 set a date a few decades earlier, but in general as one 

 proceeds backwards from this point, the evidence be- 

 comes increasingly fragmentary and uncertain. The 

 greatest source of doubt arises from the confusion be- 

 tween sundials, waterclocks, hand-struck time bells, 

 and mechanical clocks, all of which are covered by 

 the term horologium and its vernacular equivalents. 



Temporarily postponing the consideration of evi- 

 dence prior to ca. 1350, we may take Giovanni de 

 Dondi as a starting point and trace a virtualK un- 

 broken lineage from his time to the present day. One 

 may follow the spread of clocks through Europe, from 

 large towns to small ones, from the richer cathedrals 

 and abbeys to the less wealthy churches.** There is 

 the transition from the tower clocks — showpieces of 

 great institutions — to the simple chamber clock 

 designed for domestic use and to the smaller portable 

 clocks and still smaller and more portable pocket 



" .-X summary of the content of the manuscript sources, illus- 

 trated by the original drawings, has been published by H. .Man 

 Lloyd, Giovanni de Dondi's horological maslerpirce, 1364, without 

 date or imprint (?Lausanne, 1955), 23 pp. It should be re- 

 marked that de Dondi declines to describe the workings of his 

 crown and foliot escapement (though it is well illustrated) say- 

 ing that this is of the ''common" variety and if the reader does 

 not understand such simple things he need not hope to compre- 

 hend the complexities of this mighty clock. But this may be 

 bravado to quite a large degree. 



'See, for example, the chronological tables of the 14th 

 century and the later mentions of clocks in E. Zinner, Atis der 

 Friihzeit der Rddcruhr, Munich, 1954, p. 29 ff. Unfortunately 

 this very complete treatment tends to confuse the factual and 

 legendary sources prior to the clock of de Dondi; it also accepts 

 the very doubtful evidence of the "escapement"' drawn by 

 Villard of Honnecourt (see p. 107). .\n excellent and fully 

 illustrated account of monumental astronomical clocks through- 

 out the world is given by Alfred Ungerer, Les horloges aslronomi- 

 ques, Strasbourg, 1931, 514 pp. Available accounts of the 

 development of the planetarium since the middle ages are very 

 brief and especially weak on the early history: Helmut Werner, 

 From the Aralus globe to Ike Z"" planetarium, .Stuttgart, 1957; 

 C. .\. Crommelin, "Planetaria, a historical survey," Antiquarian 

 Horology, 1 955, vol. 1 , pp. 70-75. 



Figure 3. — German \\".\ll Clock, Prob.^blv .\bout 

 1450, showing the degeneration in complexity from 

 that of de Dondi's clock. 



watches. In mechanical refinement a similar conti- 

 nuity may be noted, so that one sees the cumulative 

 effect of the introduction of the spring drive {ca. 1475), 

 pendulum control {ca. 1650), and the anchor escape- 

 ment {ca. 1680). The transition from de Dondi to 

 the modern chronometer is indeed basically con- 

 tinuous, and though much research needs to be done 

 on special topics, it has an historical unity and seems 

 to conform for the most part to the general pattern of 

 steady mechanical improvement found elsewhere in 

 the history of technology'. 



PAPER 6: CLOCKWORK, PERPETUAL MOTION DEVICES, AND THE COMPASS 



85 



