Tell-Tale Clock.
Electrical Clocks have been several times planned and made by different ingenious inventors, and obtained considerable notice, but they have not been hitherto as successful as was expected. Electricity has been applied to the direct movement of the pendulum itself, and subsequently to the raising a small weight to act upon the pendulum in the style of a gravity escapement. In perhaps the latest of these instruments, called a Magnetic Clock, an electromagnet was used to relieve the pendulum from the influence of the spring by which impulsion had been given, and to make the return or reflex vibration. Electric clocks are now seldom made; electric dials without any clock-movement in connection with them are made to show the standard time by means of a galvanic current sent from the Greenwich Observatory clock at intervals of a minute or half-minute it may be,—even as Electric Timeballs show to distant towns and out-ports, by means of such a current, the exact Greenwich time once a day.
The Electro-Chronograph is a new and useful invention for timing with great precision the quickest of events. It is applied to a central seconds clock with a dial three feet in circumference showing the hours, minutes, seconds and fifths of seconds. This clock erected in a prominent position, say on a raceground, and worked by electricity, enables the starter of a race to set the works in motion; by means of a tape held up at the winning post and connected with the batteries, the winner upon breasting the tape stops the hand of the clock.
The following simple directions will be found of great use in the management of a Clock:—
When the Clock is unpacked it should be carefully handled with a silk handkerchief or piece of tissue paper, to prevent the moisture of the hands soiling the case. Unscrew the bell and take it off, then put on the pendulum by passing it through the fork, and hang it upon the two small brass pins, with the hook from you. Screw on the bell with the convex part outwards, taking care that it does not touch the pendulum.
The stand or bracket should be both steady and level before the Clock is placed upon it; for, unless the Clock is quite in proper beat—that is, unless the beats or ticks occur at equal intervals, it cannot go regularly.
In order to set the Clock to the hour of the day, the minute-hand should be turned on carefully forward with the finger and thumb, the setter pausing as he reaches the XII. and the VI., to allow the Clock to strike each hour and half-hour.
If the striking should at any time be wrong, and it should strike the hour at the half-hour, or the half-hour at the hour, the error can be rectified by moving the minute-hand on to 5 minutes before the hour, or half-hour, and then back until it strikes.