CLOCK CLOCK-WORK. 



273 



monks of European monasteries ; perhaps on the 

 contrary, they were the real inventors of it, and the 

 invention was made known to Europeans by means 

 of the crusades. In the 14th century, there are 

 stronger traces of the present system of clock- 

 work. Dante particularly mentions clocks. Richard, 

 abbot of St Alban's in England, made a clock, in 

 1326, such as had never been heard of till then. It 

 not only indicated the course of the sun and moon, 

 but also the ebb and flood tide. Large clocks on 

 steeples, likewise, were first made u?e of in the 

 14th century. Perhaps Jac. Dondi, in Padua, was 

 the first who made one of this kind ; at least his fa- 

 mily was called, after him, Dell' Orologio. A Ger- 

 man, Henry de Wyck, was celebrated, in the same 

 century, for a large clock which he placed in a 

 tower built by command of Charles V., king of 

 .France. This clock was preserved till 1737. 



Watches are a much later . invention, although 

 they have likewise been said to have been invented 

 as early as the 14th century. The general opinion 

 is, that Peter Hele first contrived them in 1510. 

 One of their names was that of Nuremberg eggs 

 (Nurnberger Eier). According to some accounts, 

 the first trust-worthy indications of their existence 

 are found at the commencement of the 17th century. 

 Galileo discovered the isochronism of the pendulum 

 from observing the equal-timed vibrations of a lamp 

 suspended from the ceiling of a church, and the 

 simple pendulum was used by him as well as other 

 astronomers of that day, as a measure of time in 

 their observations of the heavenly bodies. Huygens 

 was undoubtedly the first who applied the pendulum 

 to clock-work, and the honour of being the inventor 

 of the balance-spring in watches was contested be- 

 tween him and the English philosopher doctor 

 Hooke. To prevent friction, Facio, a Genevan, in- 

 vented the method of boring holes in diamonds or 

 rubies for the pivots to revolve in, which was found 

 a great improvement. Thus chronometers had their 

 origin, in which the English have attained great per- 

 fection. This nation also invented repeaters. An 

 individual of the name of Barlow first made one, in 

 1676, for king Charles II.; and Graham was the 

 inventor of the compensation-pendulum (q. v.), hi 

 1715. This was perfected by Harrison, who form- 

 ed the pendulum of nine round rods, five of which 

 were of iron and four of brass. With these pendu- 

 lums the astronomical clocks are still provided, and 

 perfect dependence may be placed in the regularity 

 of their action. Amongst the important inventions 

 of the 18th century, the astronomical clocks of the 

 clergyman Halm, in Echterdingen, Wurtemberg, de- 

 serve to be particularly named. See Hahn. He 

 formed the idea of measuring time in its whole ex- 

 tent. The principal hand in his instrument is that 

 of universal history. This turns on a table, and in- 

 dicates the principal epochs of history, according to 

 the chronology of the Old Testament, and the great 

 events of future times, according to the calculations 

 of Bengel, founded on the Apocalypse. Its revolu- 

 tion embraces a period of nearly 8000 years. An- 

 other hand on this table marks the year of the 

 century, and makes its circuit in 100 years. Still 

 more remarkable is the representation of the mo- 

 tions of the planets known at the time of the invent- 

 or, and ot the systems of Ptolemy and Copernicus. 

 They and their satellites perform their revolutions in 

 exactly the same time as they actually ilo in the 

 heavens ; and these automata not only have the 

 central motion, but their course is also eccentrical 

 and elliptic, like that of the heavenly orbs, and the 

 motion is sometimes slower, sometimes quicker, and 

 even retrograde. This instrument must have been 

 the fruit of deep knowledge, indefatigable research, 



and the calculations of years. It is much to be re- 

 gretted, that the limited means of the artist pre- 

 vented his machine from being better finished, and 

 that he was not acquainted with clock-making in its 

 present advanced state, and with the excellent instru- 

 ments which have been invented since his time. The 

 country where watches are manufactured in the 

 greatest numbers is French Switzerland, particularly 

 at Geneva, La-Chaux-de-Fonds, Locle, &c., where 

 they are made by thousands. Among French 

 watch-makers, Berthoud, Breguet, Chevalier, Cour- 

 voisier, Preu-d'homme, and others, are distinguished. 

 Britain and France have been active in perfecting 

 the art of horology. The elegant Parisian pendu- 

 lum-clocks are well known, in which the art of the 

 sculptor is combined with that of the machinist. 

 Elegance, however, is their principal recommenda- 

 tion. It is much to be regretted, that the present 

 watches, even the finest, have not the finish which 

 gave such great durability to those of former times. 

 Tliis is particularly the case with French watches. 

 We speak now of the better sort of watches ; the 

 ordinary ones are hardly worth the trifling sum 

 which they cost. Wooden clocks are made chiefly 

 in the Schwarzwald, or Black Forest, in South 

 Germany, and furnish an important object of manu- 

 facture for this mountainous and barren country. It 

 is said that 70,000 of such clocks are made there an- 

 nually. Perhaps this account is exaggerated, but 

 great numbers of the clocks are sent to North and 

 South America, and all over Europe. The chief 

 magazine of them is at Neustadt, in Baden. 



CLOCK-WORK. It is usual with writers on 

 clock-work to consider the moving part, or that 

 which measures the time, as independent of the 

 striking department of a common clock ; the first 

 being called the watch, and the second the clock de- 

 partment. This method we shall follow, as it tends 

 greatly to the simplification of the subject. (An end 

 view of the watch movement of a common clock is 

 shown, fig. 1, plate XV.) The work-wheel is con- 

 tained within two brass plates, SS.TT, connected 

 together by four pillars, two of which are seen 

 in the drawing. Between these two plates a 

 barrel C is placed, moving 1 on the pivots b b en- 

 tering the plates, and which terminate the axis a, a. 

 A catgut band passes round the barrel, being guid- 

 ed in winding by a spiral groove cut on the circum- 

 ference. To the end of this catgut band, or cord, a 

 weight P is attached, which, descending by its own 

 weight, will uncoil the cord, and cause the barrel to 

 turn on its axis ; and were no obstruction offered, this 

 motion would continue until the catgut were exhausted 

 or the weight reached the ground. This, however, is 

 prevented oy the action of a click fixed to the wheel 

 DD, which click strikes against the right sides ot 

 the teeth of a' ratchet wheel attached to the barrel. 

 The teeth of the wheel DD act upon the leaves of 

 the pinion turning upon the pivots c, c. The wheel 

 EE is fixed upon the axis of the pinion d, and thus 

 the motion given to that pinion by the wheel DD, is 

 transferred to the wheel EE, from thence to the pi- 

 nion e, and afterwards to the wheel FF, which again 

 gives motion to the pinion/, upon the axis of which 

 is fixed the swing-wheel GH. The swing-wheel, as 

 will )>e seen hi fig. 2, has teeth of the ratchet form, 

 in which the pallets 1R play. These pallets are con- 

 nected by a cross piece, as seen in the drawing, which 

 is fastened to an arbor going through the back plate 

 of the frame, as seen in fig. 1, and carrying the le- 

 ver XU, which has a forked end, to receive the pen- 

 dulum. To the brass bar A screwed to the frame of 

 the clock, there is attached a small steel spring y by 

 which the. pendulum is suspended. The pendulum 

 consists of a slender rod, with a heavy bob at the 



