We shall now give a brief account of the manufacture of the bell proper, i.e., the church bell of the last five centuries. It must not be supposed that the early bell-founders understood all the principles of construction, mixture of metals, lines, and proportions which go to form our notion of a good bell. As the Amati or Stradiuarius violin is the result of innumerable experiments extending over centuries, so the bells of Van den Gheyn (1550) and Hemony (1650) disengaged themselves after ages of empirical trials as the true models, and supplied the finished type for all succeeding bell-workers.
Bell-metal is a mixture of copper and tin in the proportion of 4 to 1. In Henry III.'s reign it was 2 to 1. In Mr Layard's Nineveh bronze bells, it was 10 to 1. Zinc and lead are used in small bells. The thickness of the bell's edge is 1·15th of its diameter, and its height is twelve times its thickness.
Bells, like viols, have been made of every conceivable shape within certain limits. The long narrow bell, the quadrangular, and the mitre-shaped in Europe at least indicate antiquity, and the graceful curved-inwardly-midway and full trumpet-mouthed bell indicates an age not earlier than the 16th century.
The bell is first designed on paper according to the scale of measurement. Then the crook is made, which is a kind of double wooden compass, the legs of which are respectively curved to the shape of the inner and outer sides of the bell, a space of the exact form and thickness of the bell being left betwixt them. The compass is pivotted on a stake driven into the bottom of the casting-pit. A stuffing of brickwork is built round the stake, leaving room for a fire to be lighted inside it. The outside of this stuffing is then padded with fine soft clay, well mixed and bound together with calves' hair, and the inner leg of the compass run round it, bringing it to the exact shape of the inside of the bell. Upon this core, well smeared with grease, is fashioned the false clay bell, the outside of which is defined by the outer leg of the compass. Inscriptions are now moulded in wax on the outside of the clay-bell; these are carefully smeared with grease, then lightly covered with the finest clay, and then with coarser clay, until a solid mantle is thickened over the outside of the clay bell. A fire is now lighted, and the whole baked hard; the grease and wax inscriptions steam out through holes at the top, leaving the sham clay bell baked hard and tolerably loose, between the core and the cope or mantle. The cope is then lifted, the clay bell broken up, the cope let down again, enclosing now between itself and the core the exact shape of the bell. The metal is then boiled, and run molten into the mould. A large bell will take several weeks to cool. When extricated it ought to be scarcely touched, and should hardly require tuning. This is called its maiden state, and it is one so sought after that many bells are left rough and out of tune in order to claim it.
A good bell, when struck, yields one note, so that any person with an ear for music can say what it is. This note is called the consonant, and when it is distinctly heard the bell is said to be “true.” Any bell of moderate size (little bells cannot well be experimented upon) may be tested in the following manner:—Tap the bell just on the curve of the top, and it will yield a note one octave above the consonant. Tap the bell about one quarter's distance from the top, and it should yield a note which is the quint or fifth of the octave. Tap it two quarters and a half lower, and it will yield a tierce or third of the octave. Tap it strongly above the rim where the clapper strikes, and the quint, the tierce, and the octave will now sound simultaneously, yielding the consonant or key-note of the bell.
If the tierce is too sharp the bell's note (i.e., the consonant) wavers between a tone and a half-tone above it; if the tierce is flat the note wavers between a tone and a half-tone below it; in either case the bell is said to be “false.” A sharp tierce can be flattened by filing away the inside of the bell just where the tierce is struck; but if the bell when cast is found to have a flat tierce there is no remedy. The consonant or key-note of a bell can be slightly sharpened by cutting away the inner rim of the bell, or flattened by filing it a little higher up inside, just above the rim. (See H. R. Haweis's Music and Morals, 5th edition, p. 429.)
The quality of a bell depends not only on the casting and the fineness and mixture of metals, but upon the due proportion of metal to the calibre of the bell. The larger the bell the lower the tone; but if we try to make a large E bell with metal only enough for a smaller F bell, the E bell will be puny and poor. It has been calculated that for a peal of bells to give the pure chord of the ground tone or key-note, third, fifth, and octave, the diameters are required to be as thirty, twenty-four, twenty, fifteen, and the weights as eighty, forty-one, twenty-four, and ten.
The history of bells is full of romantic interest. In civilized times they have been intimately associated, not only with all kinds of religious and social rights, but with almost every important historical event. Their influence upon architecture is not less remarkable, for to them indirectly we probably owe all the most famous towers in the world. Grose in his Antiquities observes, “Towers at first scarcely rose above the roof, being intended as lanterns for the admission of light, an addition to the height was in all likelihood suggested on the more common use of bells.”
Bells early summoned soldiers to arms, as well as citizens to bath or senate, or Christians to church. They sounded the alarm in fire or tumult; and the rights of the burghers in their bells were jealously guarded. Thus the chief bell in the cathedral often belonged to the town, not to the cathedral chapter. The curfew, the Carolus, and St Mary's bell in the Antwerp tower all belong to the town; the rest are the property of the chapter. He who commanded the bell commanded the town; for by that sound, at a moment's notice, he could rally and concentrate his adherents. Hence a conqueror commonly acknowledged the political importance of bells by melting them down; and the cannon of the conquered was in turn melted up to supply the garrison with bells to be used in the suppression of revolts. Many a bloody chapter in history has been rung in and out by bells.
