2 ON DrVIDING INSTRUMENTS. 



oti which so much of liis life has been expended ; and I 

 shall readily, th.erefore, be pardoned for saying, that con- 

 sidering some attainments which I have made on this sub- 

 ject a?! too valuable to be lost, and being encouraged abo by 

 the degree of attention which the Royal Society has ever 

 paid to practical subjetts, I feel myself ambitious of pre- 

 senting them to the public through what 1 deem the most 

 respectable channel in the world. 

 The aiihor's It was as early as the year 1775, being then apprentice to 



atteniion early brother, the late Mr. Join. Troughton, that the art of 

 turned to ir. / ' _ » » 



dividing liad become interesting to me; the stud}' of a^ 



tronomy was also new and fascinating; and I then formed 

 the resolution to aim at the nicer parts of my profession. 

 Hi^ hroher At the time alluded to, my brother, in the art of dividing, 



skiliuiinit. ^y^ justly considered the rival of Ramsden; but he was 

 then almost unknown beyond the narrow circle of the ma- 

 thematical and optical instrument makers; for whom he 

 was chiefly occupied in the division, by hand, of small as- 

 tronomical quadrants, and Hadley's sextants of large radius. 

 Notwithstanding my own employment at that time was of a 

 much inferior nature, yet 1 closely iu.spected his work, and 

 Defect of the tried at leisure hours on waste materials to imitate it. With 

 common prac- ^^ steady a hand, and as good an eye, as young men gene- 

 rally'have, , I was much disappointed at finding, that after 

 -^ having made two points, neat and small to my liking, I 



eould not bisect the distance between them, without en- 

 larging, displacing, or deforming them with the points of 

 the compasses. This circumstance gave me an early dislike 

 to the tools then in use ; and occasioned me the more un- 

 easiness, as I foresaw that it was an evil which no practice, 

 care, or habit could entirely cure : beam-compasses, 

 spvi»g-dividers, and a scale of equal parts, in short, ap- 

 peared to me little better than so many sources of mis- 

 chief. 

 Turning sup- I had already acquired a good share of dexterity, as a 

 postul tube aeneral workman. Of the ditferent branches of our art, that 

 ncirest in-rfec^ '^ , , ^ ■ i n • rrii • 



iiyji. of tvrning alone seemed tome to border on perfection. 1 his 



juvenile conceit, fallacious as I afterwards found it, fun- 

 nished the iirst tr-ain of thoughts, which led to the method 

 about to be described ; for it occurred to nie, tliat if I could 



by 



