CHIME) in its general meaning, is applied to the sound ing of bells, such as change-ringing by church bells, or the striking quarters of the hour by a clock on two or more bells, or to tunes played by a clock on a series of nine, twelve, or sixteen bells, tuned to their respective notes on the scale. Clocks that play tunes on bells are called mu sical clocks] when hour quarters are chimed or struck by the clock itself, for example, on six or on eight bells in oc tave, it is called a quarter clock, and sometimes a chime clock ; and when the quarters are struck by a string being pulled, it is called a pull quarter or a repeating clock, whe ther the quarters are struck on six or eight bells, or whe ther they are given by a double blow on the hour-bell, as in the repeating watch. A time piece, or going part, and having no hour striking part, but having a repeating part, is by some called a silent pull.
Various ways may be adopted for pricking tunes on the music barrels of clocks, The earlier mode of doing this was by taking a piece of writing paper of such a size as to cover exactly the surface of the barrel, and in a direction perpendicular to the axis of the barrel, to draw as many lines parallel to one another as there were notes in the tune to be laid down on the barrel, the lines being equidistant, and corresponding perfectly with the hammer tails as they stood in the hammer frame. They were marked at each end with the letters or notes they were to, represent in the gamut or scale of music ; and, according to the number of bars in the tune, as many spaces were made by lines drawn equidistant and parallel to each other, intersecting the others at right angles. The junction of the ends of the paper, when applied round the barrel, represented one of these bar lines. The length or breadth of the spaces (which might be either squares or parallelograms) contain ed between the bar and note lines, was again divided on the note lines into as many parts or spaces as the number of crotchets in a bar. and for notes of lesser value a less space was taken. While the paper was lying on a table, the notes in the tune proposed to be laid on the barrel were marked by a black ink dut on their respective lines, and in the same order as the bars of the music lay. After this %vas clone, the paper was pasted on the barrel ; the note lines now appeared like so many circles traced round the circumference of the barrel, while the bar lines lay longitu dinally on the surface of it. By this means the black ink dots were transferred and marked on the barrel by a punch or finger drill. This mode might answer very well where
large barrels were used, and only one tune laid on ; but in smaller work, and where several tunes were to be put on the same barrel, it is neither sufficiently neat nor accu rate.
We arc not acquainted method adopted by those workmen in London who practise the pricking of music on clock barrels ; but having had occasion to construct some musical clocks above thirty years ago, and having no oppor tunity of getting the music pricked on the barrels by any professional person, it became necessary to contrive some method for this purpose. One way consisted in applying the barrel concentric with the arbor of a wheel cutting en gine, whose dividing part consisted of an endless screw and wheel ; and having fixed other apparatus on the engine for this purpose, different numbers of turns of the endless screw were taken for the longer or shorter notes, and the tunes were as accurately put on the barrel as could be wished. Another way consisted in placing the barrel and its train of wheel work and regulating fly in the frame. A force was applied to turn the barrel, wheel work, and fly round, in the order of lifting the music hammer tails, and an apparatus was used to mark the clots on the barrel. The fly made 360 revolutions for one turn of the barrel ; or, should this be thought too quick a trail:, it might be made by altering the numbers of the wheel teeth to make 250 or 260 revolutions for one turn of the barrel ; the train or re volutions of the fly being fixed, was made use of in the same way as the endless screw in the former way, by taking a greater or a smaller number of turns of the fly for the lon ger and the shorter notes. Knowing the number of bars in the tune, and the crotchets in a bar, by calculation, the number of turns of the fly was obtained (and parts of a turn, if necessary) that a crotchet required, so that the tune might go round the barrel, leaving a small space for lock ing and running ; this was all that was required to be known : quavers and semiquavers came to have their pro portion according to the value of the crotchet. Although the process of putting tunes on barrels answered very well by both these methods, yet it was rather tedious, and at tended with some trouble and embarrassment in the ope ration; and a more simple and easier method of doing this was afterwards contrived and adopted, by which we could lay on a tune with the greatest accuracy and expedition in nearly ten minutes.