INTENTION OF CHRONOMETERS, &C. 279 



pieces. That extraordinary man, having produced the first British paiiia- 

 machines, which, upon repeated trials, met with success, to t^j^juepjece. 

 the extent required for the great reward offered by parliament, 

 must be reckoned the father of modern chronometry; and his 

 long and active career has proved extremely useful by stimu- 

 lating with so bright an example other artists to similar endea- 

 vours. The principles of Mr. Harrison's watches are well 

 known ; and, as most parts of his construction have been 

 superseded by more simple contrivances, we shall only mention 

 tlip principal inventions of which he appears to be the author, 

 and which are still used by the watchmakers of the present 

 day. 

 The going fusee is one, among those inventions,* which has Harrison ia- 

 , 1 , 1, r 1 • • T. I • • 1 vented the 



proved the most generally useful m practice. By this simple „o^-,^o-/«j^e, 



mechanism, the main spring, while the watch is going, acts on 

 an mtermed'ate short spring, which Harrison calls the secondary 

 spiJng, and is constantly kept bent to a certain tension by the 

 forir.er ; and, when the watch is winding up, and the principal Description of 

 «pnng cea-es to act, the secondary spring being placed in a jg^^ . 

 ratchet wheel, which is hindered from retrograding by a click, 

 continues the motion without alteration. Other contrivances — itsadvanta- 

 have been proposed, and executed, to make timepieces go while ^^^ ' 

 winding up; but none which, like this, combines the advan- 

 tage of simplicity, and the property of providing a supplemen- 

 tary power, which is equal to that of the main spring when its 

 action ceases. And it is to be observed, that the utility of —and great 

 the going fusee, which has induced manufacturers to Jntro- "^' '^^^"j*" ^^' 

 duce it into all good watches, is peculiarly important in those 

 timepieces which have not the power of setting themselves in 

 motion, as is the case with the best modern escapements, 



Harrison invented also a compensation for the effects of Harrison's 

 heat and cold, wliich at the time was perfectly new, and compensatioa 

 . 1 r , 1 for the effects 



Jias led to the improvements made afterwards in that essential of heat and 



requisite of timekeepers. *^<^*^- 



* We have heard that this piece of mechanism was first invented 

 by a maker of kitchen jacks; and, if so, it is not impossible but 

 tliat Harrison might have benefited by this contrivance, before his 

 .application of it to timekeepers. 



TJie 



