392 



NA TURE 



[August 25, 1887 



FIFTY YEARS 



HOROLOGY 

 branches 



PROGRESS IN CLOCKS AND 

 WATCHES.— I. 

 being one of the oldest arts anb 



general abandonment in watches of the fusee (a a, Fig 

 a contrivance of considerable antiquity, a picture of wl 

 used to appear in nearly every popular book on mechai 



of science, it is almost] inevitaeld 

 that advances in it should be of a mediocre 

 and modest character, and not of a nature to 

 claim great attention in these days of startling 

 and sensational discovery. But nevertheless 

 during the period we refer to much good work 

 has been done. In chronometers, the secondary 

 compensation error has been discovered and 

 means found to rectify it. In clocks, the same 

 has been done for the barometric error. More- 

 over, the difficulties connected with the correct 

 working of gravity escapements have been over- 

 come ; so that scarcely a good turret clock is made 

 without one now. Electricity also has been largely 

 applied for driving or controlling clocks, or for 

 controlling chronometers ; and the measurement 

 of minute fractions of a second has been attained 

 by chronographic appliances of extreme accuracy. 

 Articles explanatory of these subjects have ap- 

 peared in the pages of Nature ^ from time to 

 time. In addition there has been a mass of sub- 

 sidiary improvements which it is impossible to 

 classify, and of which we shall have to describe 

 the leading features in a somewhat desultory 

 manner in the succeeding pages. 



Fig. I. — Barrel and Fusee. 



Naturally, the first subject to claim our attention is that 

 important mechanism which enables us to wind up and 



Fig. 2. — Prest's Keyless work. 



set the hands of our watches without a key. And it is iq 

 be remarked that its introduction has led to the almost 



See vols. xiv. pp. 529, 554, 573 ; xv. 9 ; xx. 34s ; xxiii. 59 ; xxvi. 107, 

 369. 



Fig. 3.— Going Barrel and Stop-work. 



a few years ago. The discovery of such mechanism 

 not made all at once ; at first it was applied solely for 



Fig. 4. — Rocking-bar Keyless work. 



purpose of winding up the watch. The conception of ( 

 present form of winding from the pendant is due to P« 



