786 



HOROLOGY 



/, fixed to the prolonged arbor of the wheel c, 

 being caught by the pin at the end of the rack g. 

 A few minutes before the hour, a pin on the wheel, 

 h, of the dial-train, raises the arm, i, of the lifter 

 i, k, I, which in turn lifts the lever TO, which has 

 by means of its hook been holding the rack, a, fixed. 

 The tail end, n, of the rack is then forced by the 

 spring, o, against the ' snail ' p. The snail is attached 

 to the hour- wheel of the dial-train (see fig. 1), and 

 consequently revolves in twelve hours, and has a 

 step for every hour. The rack, in falling on it, is 

 freed to the extent of a tooth (i.e. a tooth gets past 

 the hook at m) for every step of the snail. As shown 

 in the fig., one tooth would be freed, and the result 

 would be that the clock would strike one ; when 

 the last step of the snail is reached, twelve would 

 be struck. The result of this movement is that 

 the striking-train moves a little till a pin on 

 the wheel d catches on the end of the lifter , 

 which is turned down through a hole in the 

 plate for the purpose. The resulting sound is 

 called ' warning. ' Precisely at the hour the pin on 

 the wheel h slips past the end, i, of the lifter, 

 which falls, relieving the striking-train ; the hours 

 are struck on the bell r, by the hammer s, acted 

 on by the pins on the wheel b. As the tumbler 

 attached to the wheel c revolves once for every 

 stroke of the bell, it gathers up a notch of the rack 

 at each revolution, until it is stopped by a return to 

 its original position of rest at the pin on the rack g. 

 The rack, lever, and lifting-piece are above the front 

 plate, and are pivoted on studs fixed into it. A 

 lever, t, moved by a pointer on the dial, throws 

 the striking work out of gear when the clock is 

 required to be silent. In the fig. u is an extra 

 wheel for driving a hand to show the days of the 

 month. 



Clocks which chime the quarters and half-hours 

 have generally a third train of wheels for the 

 chiming. 



In England clocks are principally made in 

 London and Handsworth near Birmingham, though 

 there are many small local makers. Many of the 

 ornamental clocks and timepieces are manufac- 

 tured in France. 



Dutch or wooden clocks were first introduced 

 about the middle of the 17th century. Though 

 made on the same principle as ordinary clocks, 

 their arrangements are much simplified, and their 

 principal parts made of wood ana wire, only the 

 actual wheels being brass. They are very cheap, 

 and consequently became very common in lower- 

 class households and kitchens. They are made in 

 the Black Forest in Germany, and, considering 

 their mode of manufacture, are wonderfully accur- 

 ate as timekeepers when properly taken care of. 



They are now rapidly being superseded by 

 American clocks, which, on account of their cheap- 

 ness, neatness, and portability, have become very 

 popular. Their manufacture is a great 

 industry in the United States, at Water- 

 bury in Connecticut, Brooklyn, New 

 York, and many other places. The 

 wheels .and plates are stamped, and very 

 little manual labour is spent on them, 

 every part being interchangeable in 

 similar-sized clocks. Their appearance 

 is top familiar to require a detailed 

 description. To many of these cheap 

 clocks alarums are fitted, which can be 

 set to sound at any hour. See ALARM. 



Watches. The modern perfect watch and chron- 

 ometer may be said to be the result of a gradual 

 development from the early clock rather than 

 that of any particular invention. The first step 

 was obviously to find some other form of power 

 than the weight ; and this was made in the end of 

 the 15th century by the invention of the coiled 



spring as a motive power, but where, or by whom r 

 is uncertain. 



It seems to be taken for granted that Peter 

 Hele, a mechanician of Nuremberg, as early as 

 1490 made small pocket clocks of steel which 

 showed and struck the hours, and were driven by 

 a coiled spring. These from their oval shape were 

 called Nuremberg eggs. The next step was the 

 invention of the fusee, an arrangement to overcome 

 the weakening of the spring as it became uncoiled. 

 This also is involved in obscurity, though it must 

 have occurred early in the 16th century, as the clock 

 mentioned as made by Jacob Zech in 1525 has that 

 modification. At first a gut cord was used, the 

 chain being a modern invention. The balance used 

 was exactly like that of De Vick's clock (fig. 2), 

 except that the weights on the arms of it were 

 fixed instead of hanging. The next step of any 

 consequence was the invention of the balance- 

 spring by Dr Hooke in 1658-60, which was the 

 foundation of all the varied improvements resulting 

 in the almost perfect chronometer compensation- 

 balance of the present day. 



Although watches were introduced into England 

 in Henry VIII. 's time, they did not come into 

 general use till the reign of Elizabeth, and then 

 their cost confined them to the wealthy. At first 

 they were very large, on account of their striking 

 part ; and their cases, without glass, were pierced 

 with elaborate open work to let out the sound of 

 the bell. When the striking work was dispensed 

 with, they of course became much smaller, and gradu- 

 ally drifted into being ornamental rather than use- 

 ful. They were richly ornamented with pictures 

 in enamel, set in the heads of walking-sticks, in 

 bracelets, in finger-rings, and enriched with the 

 most costly jewels. They were encased in crystal 

 and in imitation skulls, and in fact became subject 

 to all the vicissitudes of fashion, through which it 

 would be needless for us to follow them. The 

 curious will find much entertaining matter in 

 Wood's work already referred to. Previous to the 

 invention of the balance-spring, watches (as also 

 clocks ) had only one hand, which showed the hours ; 

 but after that event the greater power of regulating 

 the motion led to the introduction of extra wheels 

 to carry minute, and finally seconds, hands. 



The watch is essentially a miniature edition of 

 the ordinary spring-clock, except in two points 

 viz. that it has a balance-spring instead of a short 

 pendulum, and that, as the escapement-wheel re- 

 volves in about six seconds, an extra wheel re- 

 volving in a minute is introduced to carry the 

 seconds hand. 



The train of an ordinary verge watch is shown in 

 fig. 7 : a is the barrel enclosing the mainspring 

 and turning, by means of the fusee chain b, the 

 fusee and great wheel c, and, through the pinions 

 and wheels d, e, f, the escape-wheel g. The hands 



Fig.7. 



or motion train are exactly as described for clocks, 

 and are similarly carried by the elongated arbor of 

 the centre- wheel d. As will be seen in the fig., 

 the fusee is of a peculiar shape. The reason is as 

 follows : When the chain, which is fixed at the 

 broadest part of the fusee, is fully wound up, it goes 

 from the narrow part to the barrel where the other 



