HOROLOGY. 



145 



psjjea them, the forked end will raise up the grooved socket, 

 * and the segment which is connected with it ; hence 

 the teeth of the segment will meet with pins which art 

 T^otT t the back of the month ring, and by their means will 

 i dock, turn the month ring. On the month wheel is fixed a 

 T * pin, whrch, in common, shifts the day of the month 

 'SL'SL r ' n >" ku* '" tnose months in which there are only SO 

 ^ * * days, the pins in the elliptic plate, which press down 

 the end of the arm, make the segment be pumped up 

 only so far a* to meet with one of the pins at the back 

 of the mouthing, which is a little longer than the 

 other two ; anv one day being shifted by it, and an- 

 other by the fixed pin in the month wheel, this make* 

 the shifting from the SOth to the lt day of the suc- 

 ceeding month. The pin in the elliptic plate for the 

 Month of February being longer than the others, presaes 

 the end of the arm a little more down, consequently 

 the pumping up of the segment must be to a greater 

 height ; by this mean* the three teeth on the segment 

 get hold of the three pins on the back of the month 

 ring ; this, with the fixed pin in the month wheel, are 

 rta.iy to shift four teeth of the month ring, viz. from 

 the -JStli of relmury to the 1st of March ; and, by this 

 rery ingenious sort of mechanism, the month ring 

 bows al way * the right day of the month, except on the 

 <gth of February in leap-years. It may be in mseai I 

 to notice, that the fixed pin in the day of the month 

 wheel must be placed at such a distance from the first 

 tooth on the **gmut, a* i* equal to the space between 

 the teeth on the segment The month nng is not at- 

 tached by rollers to the back of the dial in the MM! 

 way, but run* in four roller*, which ant fixed on few 

 tod* on the fore frame plate. Thia i* for the 



.lion* of the 

 ring, when the segment i* 



tf.r |,,r,- li ,n,r p!..v. 

 ecmir iimrc ,-.,:> ti>,- 

 the month r.M/. l.i:i 



construction of the month wherl. and of theap- 

 r shifting the month ring, will be better un- 

 fren Figs. 8 and 9. where AA u the month 

 wherl; B, H, two arms or crosaes nearly similar to tho-e 

 of the month wheel, having a hole in the centre which 

 gow freely on the upper socket of the month wheel ; on 

 oneot theae arms i* a segment of a circle, nearly of the 

 same radiu. ~ that of the month wheel, baring three 

 teeth cot on it. like tfaoae of the month ring; a. a. era 

 two bra** pillars riretted on the upper side ef the month 

 enda bring formed into a 



wheel, the upper enda bring formed into a aort of pivot* ; 

 on theae anrfthementh wheel socket, the segment t* nude 

 to more freely up and down. C U a rectangular piece 

 of bran, into which a socket U riretted, which mures 

 up and down on the lower socket of the month wheel, 

 harmg a groove toned oat on it, which receives the 

 fcrke- end of the ^ w** 



*.*. 



are two 



to the rectangular piece of bra**, having two 

 in the month wheel, through which they pea* 

 *SyBii down; the other end* of them go into 

 the segment at to, and are screwed to it by mean* of 

 two .mall .crew*. On one of the arm* of the month 

 wheel is screwed a small kneed sort of cock ^ having 

 a pin fixed in it, for turning the day of the month ring 



CHAP. VIII 

 On Repeating Clocki and Watchet. 



T. theet who do not sleep well, nothing can be more 

 convenient and useful then repeater, whether it i* in 

 a watch, or in a small fixed dock. A history of this in. 



rot. it. r*T i. 



vention is given by Mr Derham in his Artificial Clock- 

 maker. Berthoud, in his llittuire, has given the fol- 

 lowing account of it, which is taken chiefly from Der- 



" The art of measuring time, (ays Berthoud,) was 

 again enriched with two fine and useful inventions be- 

 fore the end of th seventeenth century. One was the 

 equation clock ; the other, which is the most precious, 

 and of the most general utility, U that kind of striking 

 which ha* been called repeating. It is of the most inge- 

 nious mechanism, and when added to a clock, serves to 

 make known at pleasure, at every instant of the day or 

 night, without seeing the dial, the hour and the parts of 

 the hour, which are pointed out by the hands of the 

 clock. Both these inventions are due to the English 

 artist*." 



" The clocks in question here, (say* Derham,) are 



those which, by means of a cord when pulled, strike the motion. 

 hour*, the quarters, and even ome the minutes, at all k in 

 times of the day and of thenight This striking or repeat- 

 ing was invented by a Mr Barlow, towards the end of 

 the reign of King Charles II. in l6?6." 



It is not mentioned by Derham, whether Barlow WM 

 a watchmaker or not. We have heard it said by old 

 watchmakers, that be was a clergyman. This seem* in 

 some measure confirmed, by hi* having applied to Tom- 

 pion to make hi* repeating watch, when he was about 

 to obtain a patent fur the invention. 



" Thi* ingenious invention," continue* Berthoud, 

 " which had not been before thought of, made at the 

 ontaet a greet noiee, and much engaged the attention 

 of the London watchmakeri. On the idea alone which 

 each formed of it, they all set to work to try the anie 

 thing, but by rery different way* ; whence bat arisen 

 that great variety in the work of repeating motions, 

 which wa* seen at this time in London. 



" Thi* discovery continued to be practised in cham- 

 ber clock* until the reign of James II. It was then 

 applied to pocket watche*. But there arose .h-j.utr. 

 concerning the author of the invention, of which I shall 

 simply relate the facts to the reader, leaving him to 

 judge of it at he think* proper." 



Toward* the end of the reign of James II. Mr Bar- 

 low applied hi* invention to pocket watche*, and em- 

 ployed the celebrated Tompion to make a watch of 

 Una kind according to hi* ideas ; and at that time, 

 conjointly with the Lord AUebone, chief justice, and 

 tome other*, be endeavoured to obtain a patent for it. 



Mr Quare. en eminent watchmaker in London, had Quart's rt - 



not having brought it to perfection, he thought no M ^ on - 

 more of it until the noise excited by Mr Barlow'* work - 

 patent awakened in him his former idea*. He set to 

 work, and finished hie mechanism. The fame of it spread 

 abroad among the watchmaker*, who solicited him to 

 Barlow's privilege to obtain a patent. They ad- 

 tbemeclve* to the court ; and a watch of the in- 

 of each wa* brought before the king and hi* 

 council. The king, after baring made trial of them, 

 gave the preference to that of Mr Quare. 



The difference bet ween theae two inventions i* this: 

 The repetition in Mr Barlow's watch wa* effected by 

 pushing in two small pieces.one on each side of the watch 

 case, one of which repeated the hour, the other the quar- 

 ter*. Quare't watch repeated by means of one pin <>i>ly 

 fixed in the pendant ot the case, which, being pushed 

 in, made the repetition of the hour* and quarters, the 

 ante a* i* done at thi* pre.tt-nt lime, by pushing in 

 once only the pendant which carries this pin. 



