H O R O L G G Y. 
300 
in the progreflive hours, being thrown out by a lifting- 
piece H at each hour; the upper detent G being pumped 
off with the locking-piece F, from the pins in the wheel 
A. In ftriking the hour of twelve, the locking-piece, 
having arrived at the outer fpiral at H, rifes up an inclined 
plane, and drops by its own weight to the inner circle, in 
which the hour one is to be ftruck, and proceeds on in. a 
progreflive motion through the different hours till it comes 
again tp twelve. I, the hammer-work, made in the com¬ 
mon way, which is- worked by thirteen pins on the face 
of the fpiral. In fig. 61, at K, are fliown the pins on the 
face of the fpiral, which- regulate the hammer-workj and 
are thirteen in number. L, the outer pins, which lock the 
detent. M, the pump-fpring to the detent. 
In the year 1805, the fame Society voted fifteen guineas 
to Mr. Henry Ward, of Blandford, in Dorfetfhire, for a 
clock-movement, wherein the ftriking-part is fo far Am¬ 
plified, that the whole train of wheels ufed in common 
clocks, together with the barrel and weight, are entirely 
fuperfeded, and the power neceffary for railing the ham¬ 
mer is obtained from the pendulum. 
A AAA, fig. 62, represents the front fide of the frame. 
B, a cock in which refts the pivot of the pallet-arbor. C, 
a brafs arm firmly fixed on the fame. D, the gathering- 
pallet; and E, a thin plate of brafs ; both riveted on the 
lame collet, which turns on a fmall ftud fixed in the arm 
C; tins brafs plate has two notches in it, at ab, in which 
ails a llender fpring F, fattened to the collet of the arm 
C by a fmall ferevv, and ferves to.keep the gathering- 
pallet in its proper pofition. G, the cock of the hammer- 
bar. H, the hammer-tail, which aits alfo as a hook in 
the teeth of the rack. I; a brafs arm, or rather a lever, 
which lies behind the minute-wheel N, and is fixed with 
the hammer-tail to the hammer-bar by means of a pin. 
K, the flirt. M, the rack. N, the minute-wheel. O, 
the houV-wheel. The bridge and fnail are the fame as in 
a common clock. 
The operation of this work is as follows. A pin is 
fixed in the back of the minute-wheel N, and, as it re¬ 
volves, raifes the lever I, by which the hammer-tail H is 
lifted out of the rack; the rack is then at liberty to fall ; 
the lever I, by bearing againft the pin, returns gradually, 
and prevents the hammer from ftriking the bell. Before 
the uin has quitted the lever I, another pin in the front 
fide of the fame wheel begins to lift the flirt; when raifed 
to a fufficient height, it is let go by the pin, and falls on 
the gathering-pallet D, which forces it into the rack; it 
is prevented from rifing out of the rack by the fpring F 
having got into the notch b of the brafs plate E; the pal¬ 
let immediately acts on the rack; for, as the arm C 
moves from left to right, it lays hold of a tooth, and 
carries it along with it by means of the vis inertia of the 
pendulum, at the fame time the hammer-tail is raifed by 
another tooth of the rack, and on quitting it the hammer 
ftrikes the bell; when the arm C returns with tfis gather*- 
ing-pallet from right to left, the rack is prevented from 
returning with it by the tooth retting againtt the end of 
the hammer-tail; the pallet is then carried over another 
tooth, and at the next vibration moves the rack and ham- 
aner-tail as before; thus they continue to aft alternately 
on each other till the rack is up, and the clock makes 
one ftroke regularly at every other vibration. Now, in 
order to difengage the gathering-pallet, there is a pin fixed 
in the rack at c; and, as foon as the laft tooth of the rack 
has got paft the hammer-tail, the flioulder of the -brafs 
plate E, which is rivetted to the pallet, ftrikes againft the 
pin c, and lifts it out of the rack, the fpring F jumps into 
the notch a , and prevents it from returning; thus it re¬ 
mains detached, and the pendulum continues to vibrate 
without any obftruftion. The ballot' the pendulum weighs 
about eight pounds thirteen ounces: and the weight 
twenty-four pounds. The clock has a dead fcapement. 
“The objection that may perhaps be made to this clock 
(fays Mr. Ward) is, that the ftriking-part difturbs the 
ifochronifm of the pendulum ; but whoever will take the 
trouble to try it againft another pendulum of the fame 
length, both before and after it has ftruck, ,will find no 
fenfible alteration; and, even if that'were the cafe, the 
irregularities would be periodical, and return to thenw 
felves every twelve hours. The advantages which I con¬ 
ceive this clock to have over a common clock, are as fol¬ 
low : 1. That it is not attended with that difagreeable 
roaring which is frequently heard in the wheels and pi¬ 
nions of others, and particularly the fly-pivots, when in 
'Want of oil. 2. That the interval-between the ftrokes is 
uniformly the lame; the cafe is very different in other 
clocks, for as they get foul they always ftrike flower, and 
more fo ftill when the weather is cold. 3. That, in con- 
fequence of its Simplicity, it is not liable to be-out of re¬ 
pair. 4. That it can be manufaftured#or confiderably 
lefs expence.” 
To the ftriking-part of a clock are fometimes added 
chimes, a fpecies of mufic mechanically produced by the 
ftrokes of hammers againft a feries of bells, tuned agree¬ 
ably to a given fcale in mufic; the hammers are lifted by 
levers ailed upon by metallic pins or wooden pegs ftuck 
into a large barrel which is made to revolve, and is fo 
connected with the ftriking-part of the clock-mechanil'm, 
that it is fet in motion by it at certain intervals of time, 
moft ufudlly either at eveiy hour, or at every quarter of 
an hour. The mufic thus produced may coulitt of a di- 
reit fucceflion of the notes conftituting an octave fre¬ 
quently repeated, or otherwile may be a pfalm tune, or 
Ihort popular air, in the key to which the hells are tuned.' 
This fpecies of mechanical mufic is by no means calcu¬ 
lated to improve the tafte, and had its origin moft proba¬ 
bly, like clock-work itfelf, in fome of the monaftic inlti- 
tutions of Germany, where, according to Dr. Burney, it 
prevails greatly, and where the ringing of changes on 
bells, as in England, is but little, if at all, praitifed. 
The chime-mechanilm may be adapted either to aft with 
the large bells of a church fteeple, by means of wheel- 
work proportionably ftrong to raife heavy hammers, or a 
fet of bells of different diameters may be arranged con¬ 
centrically, within one another, on one common axis, 
lufficiently fmall to be introduced into the frame of a 
clock, or even of a watch, as was performed by Margetts, 
who lately died in a ftate of infanity. The manner in 
which the hammers are moved by the pins of the chime- 
barrel mutt neceffarily vary according to circumftances, 
as the wires of different rooms are differently placed to 
produce the found of a houfe-bell; bufan ingenious work¬ 
man will vary the length and fhape of his levers of com¬ 
munication agreeably to the fituation and diftance of his 
bells from the clock-work. 
In the Tranfaitions of the Society for the Encourage¬ 
ment of Arts, for 1786, is given a defeription of an im¬ 
proved piece of mechanifm of this kind, invented by Mr. 
Sampfon. The fame duty can be fafely performed by one 
train of wheels in this clock as it can by t\yo trains of 
wheels in the common one ; becaufe, in this clock, the 
wheels of communication are puttied into their place be¬ 
fore the clock gives warning, and that warning- makes it 
fafe, for the locking cannot drop into its place again, 
therefore the dock muft chime and ffrike; but in com¬ 
mon chime-clocks the ufual- way of difeharging the chime 
is by a .flirt, which in many inffances has been known to 
fail. The pieces A, B, D, and E, reprefented in the Ho¬ 
rology Plate X. at fig. 63, all move together on the centre 
C. The wheels of communication, marked 24 each, are 
both on one arbor, and communicate motion from the pin- 
wheel in the .ftriking-train to the chime-barrel. When 
the pin in the minute-wheel begins to lift the piece D, 
confequently the piece E will pulh the wheel 24 into the 
teeth of the pin-wheel, now at reft, before the clock-gives 
warning. Alfo B will be lifted out’of the locking-plate, 
and A will be moved over the detent on which is the 
hammer-tail F, and thereby pump it off the pins in the 
pin-wheel, and prevent it from ftriking the hour-bell 
while the mufic is playing. When the rack is difeharged. 
