S54 
HOROLOGY. 
'ng the points of quiefcence of all the fprings exaftly ad- 
juiled ; and alfo that the pins in the pallet-arbors be fteadily 
fixed ; for an alteration in their pofitions is in faft an al¬ 
teration in the quiefcent points of the auxiliary fprings. 
“If we were to reafon from theory,” fays the judicious 
writer of the article Chronometer in Rees’s Cyclopaedia, “ we 
lhould be difpofed, from the confideration we have given 
this mechanifm, to fay, that the principle upon which it 
is conftrufted is excellent, inafmucli as the impulfes given 
to the balance, and the oppofitions made to it during its 
vibrations, are in proportion to the diftance from the point 
of reft at all times, agreeably to the laws of gravity in a 
pendulum; the difcontinuance of the retarding force for 
a fpace of 27 0 in each excurfion deranges as little as may 
be the fcale of varying forces by which the regulation is 
effected; whereas in the other detached fcapements, where 
the impulfe from the train is momentary, fuch impulfe, 
to be powerful enough to maintain the continual motion 
of the balance, may be fuppofed to partake of the nature 
of a jerk, and to derange the regularity of the fcale of 
forces according to which the balance-fpring ought natu¬ 
rally to aft; however, in practice it has not been proved 
that this conftruftion exceeds fome of the more fimple 
ones.” 
It is faid by the younger Mr. Mudge, that his father 
conceived the idea of making a time-keeper, and had or¬ 
ganized his notions refpefting its conftruftion, fo early 
as Augult 1778, before he knew the conftruftion of Har¬ 
rifon’s ; which feems probable, from various obfervations 
made in his “ Thoughts on the Means of improving 
Watches,” publifhed in 1763, and written fome time be¬ 
fore ; but, were w r e difpofed to judge alone from a com¬ 
panion of the principles of his and Harrifon’s time-keepers, 
we lhould at leaft fay, that there is a remarkable refem- 
blance, almoft too great for accidental coincidence; the 
principle of the compenfation-mechanifm is precifely the 
fame, and the auxiliary fprings, though greatly different 
in their mode of afting, the one being before and the 
other behind the balance-wheel, the one wound up eight 
times in a minute, and the other once at each vibration, 
yet the objeft is the lame in both, namely, to give a re¬ 
gularly-modified impulfe to the balance, which balance 
again has a great momentum in both conftruftions, in 
confequence of its enlarged dimenfions. 
Though Mr. Mudge had made and approved his firft 
time-keeper previoufly to Harrifon’s having obtained his 
laft io,oool. the complement of his rewards, which fum 
was granted by parliament in 1774, yet he was unfortu¬ 
nate enough to omit making application for the trial of 
his time-keeper till the new aft had palled, which limited 
the whole reward to io,oool. or one half of that propofed 
by the aft of queen Anne, and alfo rendered the limits 
of trial more circumfcribed ; the latter of which circum- 
ftances rendered the attainment of even a portion of the 
diminilhed reward more difficult than the attainment of the 
whole great reward which Harrifon was fortunate enough 
to obtain by his indefatigable perfeverance. The aft of 
queen Anne required for Harrifon’s trial a voyage of only 
fx weeks, at the end of which, if his time-keeper was found 
to have kept time within four minutes of error, or one 
degree of longitude, he might claim a portion of the re¬ 
ward thereon; but the time fpecified in the aft of 1774 
was fx months, during which the error was not to exceed 
four minutes, for the fmalleft portion of the reward. 
In the four trials made of the time-keepers of Mr. 
Mudge by Dr. Malkelyne, from the year 1776 to 1790, it 
appeared from the doftor’s reports to the board of longi¬ 
tude, that none of the time-keepers had kept time within 
the limits preferibed by the aft of Geo. III. On the iff 
of March, 1777, however, the aftronomer royal reported 
to the board, that the firft watch made by Mr. Mudge had 
gained only i m 19 s in 109 days ; in confequence of which, 
it was refolved, that a letter be written to the navy-board 
to pay Mr. Mudge 500I. to enable him to finiih two more 
watches on a fimilar conftruftion, which was deemed pre¬ 
ferable to any other that had been previoufly tried. Mr, 
Mudge was alfo appointed watch-maker to the king, 
with an allowance of 130I. a-year, which was afterwards 
continued to his fon, of whom we are now to fpeak; for 
Mr. Mudge hirafelf, though he lived till the year 1794, ne¬ 
ver applied for any further reward ; he completed the other 
two time-keepers, according to his prcmife: he never 
made but three, though he had retired from general bufi- 
nefs in the year 1772 on purpofe to purfue this inven¬ 
tion, and make it as complete as poffible. 
Here therefore we might clofe the hiftory of this time¬ 
keeper, as far as concerns the inventor of it. But on the 
nth of June, 1791, a memorial was prefented to the 
board of longitude in the name of Mr. Mudge, (“at a 
time when age and infirmity had fo debilitated his mind 
as to render him incapable of determining for himfelf,”) 
by his fon, T. Mudge, jun. The memorial was unfuccefs- 
ful, and an appeal was made to the lioufe of commons. 
Since the publication of the Narrative, by Mr. Thomas 
Mudge, jun. it is well known what difficulties were en¬ 
countered from the oppolition which the board of longi¬ 
tude railed againft this appeal. To inquire into and af- 
certain the comparative merits of Mr. Mudge’s time¬ 
keeper, however, a committee was appointed by the houfe, 
in confequence of the appeal, conlifting of the following 
members: viz. Mr. Pitt, Mr. Fox, Mr. Ryder, Mr. Bragge, 
fir Gilbert Elliot, Mr. Gregor, fir George Shuckburgh, 
and Mr. Windham ; of whom fir George Shuckburgh was 
confidered as the friend of the board of longitude, and 
was therefore candidly propofed by Mr. Windham to 
witnefs all the meafures about to be taken. The com¬ 
mittee very properly direfted their attention, in the firft 
inftance, to two material objefts : firft, to appoint a fub- 
committee of fcientific gentlemen, and men of prafticai 
Ikill in mechanics, to examine and report their opinion 
of the principles upon which the conftruftion was found¬ 
ed ; and fecondly, to afcertain by a comparifon with other 
chronometers the accuracy which Mr. Mudge’s time¬ 
keeper had given proof of in its aftual meafurement of 
time. The fub-committee, after due examination, made 
the fubjoined report to the feleft committee, viz. “ We 
whofe names are underwritten, to whom it hath been 
referred, by a feleft committee of the honourable houfe 
of commons, to receive confidentially from Mr. Mudge 
a communication of the principles of his time-keeper, 
and to report thereon, being aflembled at the houfe of 
his excellency count Bruhl, in Dover-ftreet, on Tuef- 
day the 14th of May, 1793, did caufe a time-keeper, 
which was produced to us as one of the two made by 
Mr. Mudge, and, fubmitted to trial at the royal obfer- 
vatory at Greenwich, for twelve months, from June 1789 
to June 1790, to be taken to pieces in our prefence, by 
Mr. Matthew Dutton; and, having carefully examined 
the parts of the fame, we find a contrivance in it for defray¬ 
ing the inequalities of the maintaining-power derived from the 
main-fpring, which, as far as we know and are informed, 
is altogether new ; and having confidered the fame, and 
put many queltions concerning it to Mr. Mudge jun.. 
and Mr. Matthew Dutton, we are of opinion, that the 
faid contrivance is well calculated for producing the 
delired efteft, and that a difclolure’ of it may conduce 
to confiderable improvements in the art of making time¬ 
keepers. We moreover declare that we find great Ikill 
and ability difplayed in every part of the workmanlhip, 
as well as much ingenuity" in this particular invention. 
At the fame time it is our opinion, and we think it our 
duty to declare it fo to be, that no judgment can be 
formed of the exaftnefs of any time-keeper by a theore¬ 
tical real’oning upon the principles of its conftruftion, 
with fuch'certainty as with fafety to be relied upon,- ex¬ 
cept it be confirmed by experiments of the aftual per¬ 
formance oF the machine.” 
Notwithftjtnding this report, and the teftimonies pro¬ 
duced by Mr. Mudge in favour pf his three time-keepers, 
onemadein 1774,and the other two >n 1777, from regifters 
kept. 
