HOROLOGY. 
minion (to ufe Mr. Harrifon’s expreftlve term) over the 
wheel-work ill the regulator of a watch as in that of a 
clock. The heayieft balance that we can employ, with¬ 
out the certainty of fnapping its pivots by every flight 
jolt, is a mere trifle in comparifon with the pendulum of 
the molt ordinary clock. A dozen or twenty grains is 
the utinoft wc-ight of the balance, even of a very large 
pocket-watch. The only way that we can accumulate 
any notable quantity of regulating power in fuch a fmall 
pittance of matter is by giving it a very great velocity. 
This we do by accumulating all its weight in the rim, by 
giving it very wide vibrations, and.by making them ex¬ 
tremely frequent. The balance-rim of a middling good 
watch fnould pafs through at leaft ten inches in every fe- 
cond. Now, when we reflect on the fmall momentum of 
this regulator, the inevitable inequalities of the nvaintain- 
ing-power, the great arch of vibration on which thel'e 
inequalities will operate, and the comparative magnitude 
even of an aim oft infenlible friction or clamminefs, it ap¬ 
pears almoft chimerical to expect any thing near to equa¬ 
bility in the vibrations, and incredible that a watch can 
be made w hich will not vary more than one beat in 86,400. 
Yet fuch have been made. They mult be conlidered as 
the molt malterly exertions of human art. 
We have already laid, that the free or detached fcape- 
snent, combined with the dead-beat, is the molt likely of 
any to mealure time with accuracy. Mr. Mudge has 
given a fcapement of this kind, which he recommends for 
pocket-watches, and executed entirely to his fatisfaftion 
in one made for the queen- in the year 1770. A dead-beat 
pendulum-lcapement is interpofed between the wheels and 
the balance. The crutch EDF, fig. 87, has a third arm 
D G, ftanding outwards from the meeting of the other two, 
and of twice their length. This arm terminates in a fork 
AGB. The verge V has a pallet C, which, when all is 
at reft, would Itand between the points A, B, of the fork. 
But the wheel, by its action on the pallet E, forces the 
fork into the pofition B g b, the point A of the lork being 
.now where B was before, juft touching the cylindrical 
furface of the verge. The fcapement of the crutch EDF 
is not accurately a dead-beat fcapement, but has a very 
.fmall recoil beyond the angle of impulfton. By this cir- 
• cumftance the branch A (now at B) is made to prefs raoft 
gently on the cylinder, and keeps the wheel locked, while 
the balance is going round in the direction BH A. The 
point A gets moving from A to B by means of a notch 
in the cylinder, which turns round at the fame time by 
the aCtion of the branch A G on the pallet C ; but A does 
not touch the cylinder during this motion, the notch 
leaving free room for its palfage. When the balance re¬ 
turns from its excurfion, the pallet C ftrikes on the branch 
A, (ftill at B,) and unlocks the wheel. This now acting 
on the crutch-pallet F, caufes the branch B ot the fork to 
follow the pallet C, and give it a ftrong impulfe in the 
direction in which it is then moving, cauling the balance 
to make a femi-vibration in the direction AHB. The 
fork is now in the fltuation A ga, fimilar to B gb, and 
the wheel is again locked on the crutch-pallet E. 
The intelligent reader will admit this to be a verv 
fteady and effective fcapement. The lockage of the wheel 
is procured in a very ingenious manner; and the friftion 
. on the cylinder, neceflary for effecting this, may be made 
as fmall as we pleal'e, notwithftanding a very ftrong ac¬ 
tion of the wheel: for the preflure of the fork on the cy¬ 
linder depends entirely on the degree of recoil that is 
formed on the pallets E and F. Preflure on the cylinder 
is not indil’penfkbly neceflary, and the crutch-fcapanent 
. might be a real dead-beat; but a fmall recoil, by keeping 
the fork in contact with the cylinder, gives the molt per¬ 
fect fteadinefs to the motion. The ingenious inventor, a 
pian of approved integrity and judgment, declares that 
her majefiy’s watch was the belt pocket-watch he had 
ever feen. (Letter to Count Brahl, dated Jan. 3, 1773.) 
We are not difpoled to oueftion its excellency3 but Mr. 
Von. X. No. 665. 
345 
Mudge farther obferves, “ that it requires a delicacy in the 
execution which very few artifts are equal to, and fewer ftill 
will give themfelves the trouble to arrive at.” (Letter to 
the Count, dated Aug. 9, 1776.) 
Striking Watches are fucli as, befides the proper 
watch-part, for meafuring of time, have a clock-part, for 
ftriking the hours, See. Thefe might be calied pocket- 
clocks. 
Repeating Watches are fuch as, by pulling a firing, 
or puftiing in the pendant, repeat the hour, or quarter, 
at any time of the day or night. This repetition was the 
invention of Mr. Barlow, arid was firft put in practice by 
him in larger movements, or clocks,-about the year 1676. 
The contrivance immediately fet other artifts to work, 
who foon found out divers ways of effecting the fame. 
But its application to pocket-watches was not known be¬ 
fore James II.’s time; when the ingenious inventor above 
mentioned foiicited a patent for the fame. The talk of a 
patent engaged Mr. Quare to refume the thoughts of a 
like contrivance, which he had in view fome years be¬ 
fore: he now effected it; and, being p re fled to endeavour 
to prevent Mr. Barlow’s patent, a watch of each kind was 
produced before the king and council; upon trial of 
which, the preference was given to Mr. Quare’s. The dif¬ 
ference between them was, that Barlow’s was made to re¬ 
peat, by pufhing in pieces on each fide the cafe; one of 
which repeated the hour, and the other the quarter; whereas 
Quare’s was made to repeat by a pin that ftuck out near 
the pendant; which, being thruft in, (as now it is done 
by thrufting in the pendant itfelf,) repeated both the 
hour and quarter with the fame thruft. 
Repeating watches are in general veiy coftly; the re¬ 
pair of them is alfo expenfive, and put of London not 
many watch-makers (as they are called) are competent to 
the talk. But Mr. Elliot, of Cle-rkenwell, has lately in¬ 
vented a repeating watch on a new and very Ample prin¬ 
ciple, and as cheap as a common watch. It will repeat 
the hour and the quarter, the hour without the quarter, 
or the quarter without the hour; the hour firft, and the 
quarter afterwards, or the quarter firft, and the hour af¬ 
terwards, or the hour and the quarter without intermif- 
fion, with one hammer only. The inventor can fell a 
good repeater upon this principle for the low price of 
eight guineas; and he adds, “ my repeating movements 
can be added to an old watch for the fum of three gui¬ 
nea’s, if it is to be a dumb repeater; for a further addi¬ 
tion of three guineas, I can furniih my repeating work 
with a bell and new metal cafes.” 
The method by which this repeater is fo much Ampli¬ 
fied is by the ufe of a Angle part, fo contrived as to per¬ 
form the operations of feveral; this is, a flat ring, or cen- 
trelefs wheel, of nearly the fame diameter as the watch, 
fupported in its place, fo as to admit of circular motion, 
by four grooved pulleys placed round its external cir¬ 
cumference, in the fame manner as the part in common 
clocks which denotes the moon’s age. This_part is put in 
motion by. turning the pendant, whofe extremity is form¬ 
ed into a fmall vertical wheel, which works in teeth cut 
on the external part of the flat ring for almoft a third of 
its circumference. The lower part of the ring contains 
the pins, at right angles to its face, which lift the ham¬ 
mers for ftriking the hours and quarters; the internal 
part of the ring contains indentations of regularly-increaf- 
ing depths, which, receiving the tails of the levers, whofe 
other extremities are preifed by their fprings againft the 
hour-fnail and the quarter-fnail, is by them prevented 
from moving beyond a certain degree proper for the time; 
after the pendant is turned, the ring is brought back to 
its firft pofition, by a box-fpring, round which a fine 
chain is coiled, whofe extremity is connected with the in¬ 
ner part of the ring. By turning the pendant to the left 
the hour is ftruck, and by turning to the right the quar¬ 
ters are repeated ; and the returning lp ring juft mention¬ 
ed is made to operate in both directions, by its chain 
4-.T puffing 
