23$ Principles of portable Time Pieces. 



explained above twenty fevcral methods of application, and how the vibrations might be fo 

 regulated as to make their durations either all equal, or the greater flower or quicker than 

 the lefs, and that in any proportion affigned. Some of thefe ways were applicable to 

 lefler vibrations ; others to greater, as of 2, 3, 4, 6, or what number of revolutions 

 were defired ; the models of which he produced in the lefture. 



As his poftfcript is dire£led in controverfy againft Mr. Oldenburg, the writer of the 

 Philofophical Tranfaflions, and in part againft M. Huyghens, who adopted the pendulum 

 fpring, and has defcribed Hooke's circular pendulum to clocks in his book de Horologio 

 Ofcillatorio, without mentioning the inventor: it contains fome matters of proof and 

 animadverfion, into which I have no prefent intereft to enter ; but conclude with quoting 

 his own words refpe£ting the copy I fend you, begging leave to enter my humble proteft 

 againft the injuiidlion of fecrecy, which a fenfe of undeferved injury may, perhaps, have 

 extorted from this great man (page 30.) 



" I fliall conclude this tract with a fliort communication of the general ground of my 

 " invention [or pocket -wafches, the number of particular ways being very great, which (that 

 " the true lovers of art, and they only may have the benefit of) I have fet down in the 

 " univerfal and real chara£ler of the late reverend prelate my honoured friend Dr. John 

 " Wilkins, lord bifliop of Chefter, deceafed. In which 1 could with all things of this 

 " nature were communicated, it being a character and language fo truly philofophical, 

 " and fo perfeftly and thoroughly methodical, that there feemeth to be nothing wanting to 

 " make it have the utmoft perfeftion, and higheft idea of any charadter imaginable, as 

 " well for philofophical as for common and conftant ufe. And I have this further to 

 " defire of my reader, who will be at the pains to decipher and underftand this defcrip- 

 *' tion, that he would only make ufe of it for his own information, and not communicate 

 "the explication thereof to any, that hath not had the fame curiofity with himfelf." 

 See Plate X. 



*' This I do not fo much to hinder the fpreading of this defcription here delivered, as 

 •' to revive, and, if poffible, bring into ufe and pradtife that excellent defign : it being a 

 " charafter and language perfectly free from all manner of ambiguity, and yet the moft 

 " copious, expreflive, and fignificative, of any thing or notion imaginable, and which 

 " recommends it moft to common ufe, the moft eafy to be underftood and learnt in the 

 ''world*." 



I am, 



SIR, 



Your obliged reader, 



M. M. 



• For forae account of Bifhop Wilkins's book fee our Journal, M, 346.. --N, 



Scientijic 



