four bells to give the pure chord of ground tone (key-note), third, fifth, and octave, the diameters require to be as 30, 24, 20, 15, and the weights as 80, 41, 24, 10. A smaller quantity of metal than is due to the calibre of the bell, though giving the same note, produces a meagre, harsh sound; and the real or fancied superiority in dignity of tone of some old bells is ascribed to a greater weight of metal having been allowed for the same note than modern economy would dictate. Bells have been cast of steel, some of which have had a tone nearly equal in fineness to that of the best bell-metal, but deficient in duration, having less vibration. Some have also been cast of glass, with a considerable thickness of the material; and these give an extremely fine sound, but are too brittle to stand the continued use of the clapper.
The manufacture of bells is simply a process of founding. A core is first constructed of brickwork, which is covered with layers of clay which, by means of a template, is formed to the exact form and dimensions of the interior of the bell to be cast. On this mold is laid a 'model' of earth and hair, which is the exact counterpart of the future bell. A third and heavy shell is then built over the model, which, when completed, is lifted, and the 'model' is broken away from the core, and the outside shell is then replaced, leaving a space between it and the core the exact size and sluipe of the 'model.' Into this space the molten bell-metal is run and allowed to cool.
From old usage, bells are intimately connected with the services of the Christian Church, and thus have acquired a kind of sacred character. They were founded with religious ceremonies, and consecrated by a complete baptismal service; received names, had sponsors, were sprinkled with water, anointed, and finally covered with the white garment of chrisom, like infants. This usage is as old as the time of Alcuin (735-804) and is still practiced in Roman Catholic countries. Bells had mostly pious inscriptions, often indicative of the widespread belief in the mysterious virtue of their sound. They were believed to disperse storms and pestilence, drive away enemies, extinguish fire, etc. A common inscription in the Middle Ages was:
Funera plango. fulgura frango, Sabbata pango,
Excito lentos, dlssipo ventos, paco cruentos.
Church bells were at one time tolled for those passing out of the world. It was a prevailing superstition that bells had the power to terrify evil spirits, no less than to dispel storms; and the custom of ringing what was called the passing-bell "grew (vide Quarterly Review, September, 1854) out of the belief that devils troubled the expiring patient, and lay in wait to afflict the soul the moment when it escaped from the body. . . . The tolling of the passing-bell was retained at the Reformation; and the people were instructed that its use was to admonish the living, and excite them to pray for the dying." But "by the beginning of the Eighteenth Century the passing-bell, in the proper sense of the term, had almost ceased to be heard. The tolling, indeed, continued in the old fashion; but it took place after the death, instead of before." The practice of slowly and solemnly tolling church bells at deaths, or while funerals are being conducted, is still maintained as a mark of respect for the deceased. The pardon-bell of pre-Reformation England was tolled before and after divine service, to call the worshipers to a preparatory prayer to the Virgin Mary before engaging in the solemnity, and an invocation for pardon at its close. Bishop Burnet has recorded the order of a bishop of Salisbury, in 1538, concerning the discontinuance of the custom. It runs thus: "That the bell called the pardon or ave bell, which of longe tyme hathe been used to be tolled three tymes after and before divine service, be not hereafter in any part of my diocesse any more tollyd."
The ringing of the curfew-bell, supposed to have been introduced into England by William the Conqueror, was a custom of a civil or political nature, and only strictly observed till the end of the reign of William Rufus. Its object was to warn the public to extinguish their fires and lights at eight o'clock in the evening. The eight-o'clock ringing is still continued in parts of England and Scotland.
The hanging of bells in dwelling-houses, and ringing them by means of wires from the different apartments, is a comparatively modern invention; for it was not known in England in the reign of Queen Anne. The form of bell now most commonly used for houses and for call-bells in hotels, business houses, etc., is the electric bell. The arrangement required to ring a bell or system of bells by electricity is simple. Some form of galvanic battery requiring little attention is placed in any convenient corner, and from it an insulated wire, with the necessary branches, is conducted to the various rooms; thence to, perhaps, as many bells, and finally back to the battery to complete the circuit. Each single bell is provided with a clapper, to which is fixed a piece of soft iron. Near this is an electro-magnet, wound with a quantity of insulated wire, to which the main wire is connected, so that upon the passage of the signal current the magnet attracts the piece of iron fastened to the clapper, and the clapper strikes the bell. In this way any number of bells may be rung at once by sending a powerful current through the wire to which they are all connected. Such arrangements of bells are used very extensively for giving signals simultaneously in a number of rooms or buildings—for example, for striking the hours in all of the rooms of a school-building; for sounding alarms of fire throughout hotels or large buildings, etc.
Bells for continuous vibratory ringing are of the same construction as those just described, excepting that they are provided with a device for continuously vibrating the clapper while the bell is being rung. The wire, instead of being connected directly to the coil around the magnet, is connected to a post, against which the clapper rests after striking the bell. The coil is connected to the clapper, and the current passes through the post, and the clapper to the coil. When a signal on the wire causes the magnet to attract the clapper and strike the bell the connection is immediately severed by the clapper leaving the post, and no more current can pass until the clapper has returned after striking the bell. Instantly when this occurs the connection is reëstablished, the clapper reattracted, and the bell again struck. Thus a continuous ringing is produced as long as the person presses the calling-button. This push-button is simply
