\}.\V ob\i feir ova utt aa>;^< ttiatv 



Figure 20. — Arrangement for Turning a Figure 

 OF AN Angel. It has been alleged that this drawing 

 by Villard represents an escapement. After Lassus 

 (see footnote 37). 



We have reserved to the last one section of evidence 

 which may or may not be misleading, the famous 

 notebook of Villard (Wilars) of Honnecourt, near 

 Cambrai. The album, attributed to the period 1240- 

 1251, contains many drawings with short annotations, 

 three of which are of special interest to our investi- 

 gations.'" These comprise a steeplclike structure 

 labeled "cest li masons don orologe" (this is the 

 house of a clock), a device including a rope, wheel 

 and axle (fig. 20), marked "par chu fait om un 

 angle tenir son doit ades vers le sclel" (by this means 

 an angel is made to keep his finger directed towards 

 the sun), and a perpetual mction wheel which we 

 shall reserve for later discussion. 



The clock tower, according to Drover, shows no 

 place for a dial but suggests the use of bells because 

 of its open structure, suitable fcr letting out the 

 sound. Moreover, he suggests that the delicacy of 

 the line indicates that it was not really a full-size 

 steeple but rather a small towerlike structure standing 



2' The album was published with facsimiles by J. B. A. 

 Lassus, 1858. .\n English edition witli facsimiles of 33 of the 

 41 folios was published by Rev. Robert Willis, Oxford, 1859. 

 An extensive summary of this section is civen, with illustrations, 

 by J. Drummond Robertson, The evolution 0) ilockwork, London, 

 1931, pp. 11-15. 



only a few feet high within the church. There is, 

 alas, nothing to tell us about the clock it was intended 

 to house; most probably it was a water clock similar 

 to that of the illustrated Bible of ca. 1285. 



The drawing of the rope, wheel and axles, for 

 turning an angel to point towards the sun can have 

 a simple explanation or a more complicated one. 

 If taken at its face value the wheel on its horizontal 

 axis acts as a windlass connected by the counterpoised 

 rope to the vertical shaft which it turns, thereby 

 moving (by hand) the figure of an angel (not shown) 

 fi.xed to the top of this latter shaft. Such an explana- 

 tion was in fact suggested by M. Quichcrat,** who 

 first called attention to the Villard album and 

 pointed out that a leaden angel existed in Chartres 

 before the fire there in 1836. It is a view also sup- 

 ported from another drawing in the album which 

 describes an eagle whose head is made to turn towards 

 the deacon when he reads the Gospel. Slight pressure 

 on the tail of the bird causes a similar rope mechanism 

 to operate. 



A quite different interpretation has been suggested 

 by Fremont;'" he believes that the wheel may have 

 acted as a fly-wheel and the ropes and counterjwises, 



'*' M Jules Quichcrat, Revue Archiologique, 1849, vol. 6. 

 ■^" Nf. C. Fremont, Origine de I'hoiloge a poids, Paris, 1915. 



Figure 2 1 . — Villard's Perpetual Motion Wheel, 

 from Lassus (sec footnote 37). 



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



107 



