CLOCK. 



its structure, and the precision of its per- 

 formance, and which therefore possessed 

 considerable merit as a piece of mechan- 

 ism ; but neither of those inventions be- 

 ing 1 of any service to the great object of 

 lioroiogical machinery, namely, the pre- 

 cise and accurate measurement of time, 

 we have thought a farther description of 

 them needless here. 



Clocks being considered in this point 

 of view, as they doubtlessly should be, 

 no great estimation can be attached at 

 present to those clocks on the continent, 

 which were formerly so famous, whose 

 chief object seems to have been to set a 

 number of puppets in motion at stated 

 times. Of these the clocks of Stras- 

 burgh and of Lyons were the most noted. 

 In the former a cock claps his wings, 

 and proclaims the hour ; and puppets, 

 intended to represent an angel, the Vir- 

 gin, and the Holy Spirit, appear : the an- 

 gel opens a door, and salutes the virgin, 

 and the Holy Spirit descends on her. In 

 the clock of Lyons two horsemen en- 

 counter, and beat the hour on each 

 other ; a door opens, and there appears 

 on the theatre the image of the Virgin, 

 with that of Jesus Christ in her arms; 

 the Magi, with tneir retinue, marching 

 in order, and presenting their gifts ; 

 two trumpeters sounding all the while, 

 to proclaim the procession. Clocks with 

 chimes are of the same nature with those 

 described. 



In nearly the same rank with the fore- 

 going must be classed the clocks made 

 to register the motions of the heavenly 

 bodies- they can be only considered as 

 objects of curiosity, since in point of 

 utility, in noting the position of the 

 heavenly bodies, the common nautical al- 

 manacs are so superior, as to render it 

 in some degree ridiculous to compare 

 them together. The clock of the royal 

 palace at Hampton Court is one of the 

 most noted of those which have move- 

 ments of this nature ; but other consider- 

 ations render this clock an object of 

 great interest. According to Dr. Dei-ham, 

 it is the oldest English clock extant, hav- 

 ing been constructed in the year 1540, in 

 the reign of Henry V11I. It shews the 

 time of the day, and the motion of the 

 sun and of the moon through all the de- 

 grees of the zodiac, together, with the 

 day of the month, the moon's southing, 

 and other matters. These motions are 

 the more deserving attention, as, at the 

 time the clock was made, Copernicus, 

 then living, had not published his book 

 " On the Revolutions of the Celestial 



Orbs." And besides this, the pendulum 

 was not applied as a regulator of clocks 

 for nearly a century afterwards. 



A fe\v clocks have been constructed 

 with a view directly contrary to those 

 described, in which simplicity of parts 

 was as much studied as great variety 

 of movements were in the others. Of 

 the clocks of this simple structure, none 

 have as yet exceeded that contrived by 

 the celebrated Dr. Franklin .- it shows 

 the hours, minutes, and seconds, and yet 

 consists of but three wheels, and two pi- 

 nions. The lowest wheel contains 160 

 teeth, and goes round once in four hours; 

 it carries the hand on its axle, which 

 points out both the hours and the mi- 

 nutes, as will be described ; and it turns 

 a pallet above it of ten leaves, on the 

 same axis with which is a wheel of 120 

 teeth, that gives motion to a pallet of 

 eiglu leaves. The second hand is annex- 

 ed to the same axis with this latter pallet, 

 as also the swing wheel, which carries 30 

 teeth, that gives motion to the pallets 

 of an anchor escapement, and to its pen- 

 dulum that vibrates seconds. The dial of 

 this clock is of a singular formation. The 

 external circle on k contains 240 divi- 

 sions, numbered from 1 to 6J, in four 

 successive notations. This circle shews 

 the minutes : within it the hours are 

 arranged in four concentric circles, or 

 in a volute of four revolutions, along 

 four radii, which form right angles 

 with each other. By this arrange- 

 ment, while the point of the hand shews 

 the minute, its side exhibits the hour ; 

 or, more strictly speaWng, shews that 

 the hour is one of three ; but so that it 

 will hardly ever happen that any doubt 

 will remain of which it may be, as there 

 are four hours difference between the 

 figures next to each other on the same 

 radial line. A small circle is placed 

 above the great one, and divided into 60 

 parts for the seconds. This clock was 

 wound up by a line going over a pulley 

 and ratchet on the axis of the great 

 wheel, by which the weight was drawn 

 up in the same manner as in the common 

 wooden clocks. Many of these clocks 

 have been made, which are found to mea- 

 sure time exceedingly well. 



The small imperfection in this clock, 

 of its leaving the uncertainty mentioned 

 as to which of three hours it denotes, 

 though so easily corrected by the judg- 

 ment, has given rise to some ingenious 

 contrivances to obviate it. 



That of Mr. Ferguson is best known, 

 in \vhir.h the hours were engraved on the 



