By this means a full chime clock may be had at much less cost than if the whole apparatus had to be self-contained and the facilities of separation between the chimes and the timekeeping apparatus, as hinted above, gives many advantages. For instance, the same clock and controller may operate tubes inside the room and bells outside, or vice versa. These are operated by wet or dry batteries purchased at local electrical supply houses, and the wiring is done with plain covered bell wire, or they may be operated by current from a lighting circuit, suitably reduced, if the current is constantly on the mains. As a full chime with sixteen notes at the hour strikes more than a thousand times a day, considerable care should be taken to obtain only the best batteries where these are used, as after the public gets used to the chimes the dealer will be greatly annoyed by the number of people asking for them if they are stopped temporarily.
There has lately developed a tendency to avoid the set tunes, such as the Westminster and the Whittington chimes, and to sound the notes as complete full notes, such as the first, third and fifth of the octave for the first, second and third quarters, followed by the hour strike. This allows them to be struck in any order and for a smaller chime reduces the cost considerably. The tubes used are rolled of bell metal and vary in pitch with the manufacture, so that the only way to obtain satisfactory tones is to cut your tubes a little long and then tune them by cutting off afterwards, the tone depending upon the thickness of the wall of the tube and its length. The bells are tuned by turning from the rim or from the upper portions as it is desired to raise or lower the tone, and if the resonators are used they are tuned in unison with the bells.
Fig. 148. Connections and contacts on front of clock dial.
Of the ordinary bells, [Fig. 144], the dimensions run: First, height four inches, diameter 5½; second, height four inches, diameter 5¼ inches; third, height 4½ inches, diameter 5⅝ inches; fourth, height 4½ inches, diameter 5⅝ inches; fifth, height 4⅝ inches, diameter 6½ inches. For the tubes the approximate length is six feet for the longest tube and the total weight of the chimes is 43 pounds. For the controller the size is nine by eleven by six inches, with a weight of ten pounds. The hour strike may be had separately from the chimes if desired.
Fig. 149. Connections and wiring on back of clock dial.
This makes an easily divisible system and one that is becoming very popular with retail jewelers and to some extent with their customers.