the pin N then slipping past it. Then the train is free; the striking
wheel begins to lift the hammer, and the gathering pallet gathers up the
rack, a tooth for each blow, until it has returned to the place at which
the pallet is stopped by the pin K coming under it. In this figure the
lifting-piece is prolonged to F, where there is a string hung to it, as
this is the proper place for such a string when it is wanted for the
purpose of learning the hour in the dark, and not (as it is generally
put) on the click C; for if it is put there and the string is held a
little too long, the clock will strike too many; and if the string
accidentally sticks in the case, it will go on striking till it is run
down--neither of which things can happen when the string is put on the
lifting-piece.

The snail is sometimes set on a separate stud with the apparatus called
a _star-wheel_ and _jumper_. On the left side of the frame we have
placed a lever x, with the letters st below it, and si above. If it is
pushed up to si, the other end will come against a pin in the rack, and
prevent it from falling, and will thus make the clock silent; and this
is much more simple than the old-fashioned "strike and silent"
apparatus, which we shall therefore not describe, especially as it is
seldom used now.

If the clock is required to strike quarters, a third "part" or train of
wheels is added on the right hand of the going part; and its general
construction is the same as the hour-striking part; only there are two
more bells, and two hammers so placed that one is raised a little after
the other. If there are more quarter-bells than two, the hammers are
generally raised by a chime-barrel, which is merely a cylinder set on
the arbor of the striking-wheel (in that case generally the third in the
train), with short pins stuck into it in the proper places to raise the
hammers in the order required for the tune of the chimes. The quarters
are usually made to let off the hour, and this connexion may be made in
two ways. If the chimes are different in tune for each quarter, and not
merely the same tune repeated two, three and four times, the repetition
movement must not be used for them, as it would throw the tunes into
confusion, but the old locking-plate movement, as in turret clocks; and
therefore, if we conceive the hour lifting-piece connected with the
quarter locking-plate, as it is with the wheel N, in fig. 26, it is
evident that the pin will dischar