420 TiME KEEPERS* 



Defcripdon of Upright pillars; the uppermoft of thefe plates Is that which if5 

 the Efcapemcnt reprefeiited by Fie. Ml plate XIII, where PQRS are the foUi^ 

 of Mr. Earn- ,. ' , ■'. ° ,,,.■, r mi i 



ihaw'srimc Icrews that take into (he heads ot the four pillars above men- 

 piece, lioned, and conne6l it to the remaining part of the model. 

 The plate PQRS contains, however, the whole of the parts 

 necedary for the prefent purpofe. The fide of this plate re- 

 prefented to view, is the undermoft when fixed in the model; 

 fo that the figure reprefents this plate as taken off, with the 

 fide next to the balance laid upon a table, and the eye is fup- 

 pofed to be placed perpendicular over it. 



In the plate PQRS is an opening, or a piece taken out, 

 reprefented by TUWXYZ. In this opening, the balance- 

 wheel ABCD, pallet MSK, and part of the balance UV arw 

 feen. The balance-wheel is fupported by two pieces of brafs, 

 ONH, OI; the piece ONH is fcrewed to the fide of the 

 plate neareft to view by a ftrong fcrew t, and made firm by 

 fmall pins reprefented by t tt r TTTrw-; thefe pins are called 

 Heady pins ; they are riveted faft into the fupporling piece 

 OH, and take into holes in the plate PQRS, made exaflly to 

 fit them. The part ON of this fupporting piece is fuppofed 

 to be raifed above the part f H by a joint or bend at N ; the 

 bther fupporting piece 01 is faflened to the oppofite fide of 

 the plate ; and between thefe two pieces the balance-wheel 

 turns freely and fleadily in the dire6tion of the letters ABCD. 

 The fmall wheel MSK is called the large pallet; it is a 

 cylindrical piece of fteel, having a notch or piece cut out of it 

 at /A r; againft the fide of this notch is a fquare flat piece ot 

 roby, or any hard ftone, h I, ground and polifiied very fmooth, 

 and fixed faft into the pallef. The cylinder is fo placed, with 

 refped to the balance-wheel, thai it may not be more than juft 

 clear of two adjoining teeth. EF is a long thin fpring, whicji 



(which laft :ippears in No. 55 of our Journal) as they have been fo 

 highly diftinguiihed by the national munificence. Some difcujfion 

 of the important fubject of time pieces may be feen in the Phitof. 

 Journal, quarto feries. Vol. I. 56, and Vo!. II. 106. As I expcft 

 ihortly to be favoured with a valuable communication refpefting 

 the original inventors of free 'Scnpements and compenfntions, and 

 may, according to circumftances, offer a few remarks on the 

 fubjeil myfiilf, I have bcsn cartful in the firft place to give the 

 accounts of the above mentioned artifts in their own words. 



. W. N. 



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