June 5, 1885.] 



♦ KNOWLEDGE ♦ 



481 



The numerous machines employed are, on the score of 

 accuracy and good workmanship, as well as on that of 

 economy, designed and constructed on the premises; and in- 

 deed no eflbrt seems to have been sjiared to make the factory 

 as independent as possible of other houses. Primarily, 

 the movement of a watch is made up of two plates, and 

 the wheels, ic, between them. The plates are kuown 

 as the pillar plate and the top plate. In full plate 

 watches the top is wholly closed or covered. Tlie top 

 of a three-quarter plate watch is tUish with the balance 

 bridge and about one - quarter of the plate is cut 

 out to allow the planting of the balance — hence the 

 name " ^ plate.'" All Waltham watches have what is 

 called a going barrel, instead of the fusee, preferred 

 in the English system. The going barrel contains the 

 mainspring, and drives the centre wheel and pinion, which 

 revolve once an hour, carrying the minute hand. The third 

 wheel and pinion are simply intermediate between the 

 centre wheel and the fourth wheel, which carries ou its 

 staff the second hand, revolving once a minute. Th(! 

 fourth wheel also drives the escape wheel, so called 

 because it only lets one tooth escape at a time, bringing 

 the machine to a dead stop five times every second. They 



The minute and hour wheels are located under the dial, 

 and are driven by a system of gearing. The cannon pinion 

 tits friction tight on the centre stall', being so put on to 

 enable the hands to be set. The cannon pinion drives the 

 minute wheel, and the minute pinion drives the hour 

 wheel ; the proportion being such that while the former 

 revolves once an hour, the latter revolves once in twelve 

 hours. Most of the watches now made are wound up by 

 turning the crown of the case, and the hands also are sot 

 by a similar device, dispensing wholly with the watch- 

 key. 



The safety of the movement from any injury that might 

 result from the breaking nf th(^ main spring is secured by a 

 safety pinion screwing on to tht; arbour of the centre wheel 

 by a triple left hand thread. Should the main-spring break, 

 the recoil would merely unscrew this pinion, and thus 

 release the whole movement witiiout any consequent 

 damage. 



Tiie manufacture of the various parts of a watch is- 

 carried on in dillerent rooms, each room being set apart 

 for a particular kind of work. Thus, in the plate room 

 (Fig. 2) the pillar and top jilates are made, the material 

 generally employed being brass. Hero as many as IT)! 



used to make all watches with 14,400 beats to the hour (or 

 four to the second) ; this is called "slow train," and is 

 now obsolete except for one-quarter second watches. The 

 English standard was advanced to 16,200 beats to the 

 hour (four and a-half to the second). The Waltham 

 standard is now 18,000 beats to the hour (five to the 

 second), called "quick train." Experiments have also 

 been made up to 21,000 beats to the hour (or six to the 

 second), called " fast train," but results are not satis- 

 factory. 



All Waltham watches are provided with "lever escape- 

 ment." The lever consists of a pallet and fork, and receives 

 an oscillatory movement from the escape-wheel. The 

 balance, to which the lever imparts motion through the 

 medium of the roller jewel pa.ssing alternately in and out 

 of the fork, regulates the whole watch. It consists of a 

 comparatively heavy wheel running on an axis with finely- 

 adjusted pivots and with the least possible friction, and a 

 hair-spring attached at one end to the balance-wheel and at 

 the other to the balance-cock, which is fastened to the top 

 plate. The value of the hair- spring is to secure uniformity 

 of vibration of the balance-wheel ; the balance is bimetallic, 

 to correct the contraction or expansion of the hair-spring 

 on the degradation or exaltation of temperature. 



operations are performed, 80 of them being in connection 

 with the pillar-plate alone. 



(To be contmued.) 



editorial #osei(p. 



There are but few amateur astronomers indeed who will 

 not mourn for the death of the Rev. Prebendary Webb, 

 and in some sort feel as though a personal friend had been 

 taken from them. For surely no one during the present 

 generation had done so much to popularise oVwervational 

 astronomy as the late vicar of Hardwick, whose " Celestial 

 Objects for Common Telescopes " is employed as a hand- 

 book in nearly every observatory in the kingdom. But, 

 although this is the work with which his name is most 

 widely associated, and Vjy which he will be best remem- 

 bered, he was, further, a prolific writer in various periodicals 

 on astronomical subjects generally, and we have had the 

 privilege of numbering him among the contril»utors to our 

 own columns. The gentleness and simplicity of his life 

 were reflected in his writings, with the charm of which so 

 manv who will read these lines must be familiar. Latterly, 



