\\-^ MR. hardy's banking. 



XV. 



Defcription of an accurate Method of banking the Balance of 

 a Time-keeper. By . Mr, William Hardy. ExI. raSttd 

 * from his Letter to C has. Taylor, Efq. Sec. to the kS ucielj/ 



of Arts.* 



SIR, 



Importance of A HIS letter is acconrpanied with a drawing, a defcription, 



theftoporbank-g^j a model, of a more perfed mode of banking: the balance 



ing piece ufed to . ' ° 



prevent extreme of a time-keeper, than any that has yet appeared ; and its ap- 



vibrations in plication to a time-keeper is a matter of Inch real importance, 

 that tiie mofl accurate, without this mofl: necetlary appendage, 

 is liable to fuch derangement, that from the raoft trivial caufe 

 it is in onemoment rendered ufelefs. 

 The author's in- To preferve the good qualities of the time-keeper, on 

 vention is con- which often the ftrength, the wealth, the grandeur, and fafetj 

 trial of this great empire depend, I deem it neceifary that my in- 



vention fhould be laid before the Society of Arts, as the means 

 of its being more generally known; and I hope that I (hew 

 proper reiped to the Society, when I aflure you that I do not 

 ofTeV^giny crude idea, neither could I think of giving you any^ 

 trouble, until J had fully verified the utility of my, contrivance 

 and teftlmony. by feveral years trial. As I can produce the leftimony of 

 fopie of the moft eminen't watchmakers in favour of my inven- 

 tion, 1 look forward with fome degree of confidence, ia ex- 

 pectation of obtaining the approbation of the Society. 

 The banking is It vvas at firft imagined, that a banking to a watch with a 



required in free efcapement was quite unneceflary, as the limits of bank- 

 watches which . /. ■ 1 • r 1 D • 

 have a vibration '"g were fo great as to admit ot almolt twice 360, , or 720 de- 



through very grees ; but, on trial, the balance was frequently found to ex- 

 ceed this quantity, and that a very flight motion given to the 

 time-keeper [particularly when the axis^ of the balance be- 

 came the axis, of that motion), was. fufficient to alter the 

 itrength and figure x)f the pendulum-fpring, and pofition of 

 the pieces in refpecl of the balance-wheel, lb as to change the 

 rate 'of the titiie-keeper ; and, what was worfe, require a 



* In their Memoirs for 1804. A premium of 30 guineas was 

 •Awarded for this invention. 



new 



