A Dictionary of Music and Musicians/Bells
BELLS. Musical instruments of metal, sounded by percussion, and consisting of a cup or bowl, caused to vibrate by the blow of a 'clapper' or hammer on the inner or outer surface of the bell. The external stroke, however, is only applied in special cases, as when a large bell is connected with a clock, and the hours struck upon it with an external hammer worked by mechanical means; or when a series of bells are arranged so that set compositions can be played upon them by a series of such hammers, and with musical precision. [See Carillons.] A fixed bell can also be played by an internal hammer pulled or struck against the inside. But the essential and typical form of the bell is that in which the stroke is given by a movable clapper hung within the bell, and caused to strike by swinging the latter, either by hand (in the case of small bells) or by a wheel and pulley system in the case of large ones. Bells have also been extensively used as personal ornaments and decorations, from those on the hem of the garment of the Jewish high-priest to those which formed the appendages of the head-dress of the mediaeval jester. This decorative use of bells has also been applied to domestic animals; and the bells of the English waggoner's team were formerly as common an appendage as the sheep-bells and goat-bells in Switzerland and elsewhere, and the cow-bells in the New Forest, still are. In these cases the sound of the bell is excited by the movements of the body. But in all these forms or applications of the bell the principle is the same; it is an instrument with a hammer hung loose inside it, and caused to sound by the agitation, regular or irregular, communicated to it, and by which the hammer is made to strike against the inside. It is important to note this as the essential characteristic of bells, and that which distinguishes their special place among musical instruments. Of music, in the artistic sense of the word, bells in their true form are hardly capable. They may be tuned to a regular scale, and sounded in various successions, but the method of obtaining the sound by swinging the bell till the clapper hits it (by which method alone the full sound can be elicited) necessarily precludes anything like the exactitude in time or the variation in intensity by which form and expression are given to music. All the contrivances for performing music on bells with mechanical precision involve a greater or less departure from the true principle of the bell, and an impairing of its characteristic sound by fixing it instead of letting it swing freely. It will be seen, therefore, that bells form a kind of connecting link between the music of art and the music of nature; their fixed tone and synchronous vibrations connecting them with the art, while the irregular and formless character of the music produced from them even by the best peal-ringers, partakes of the wildness and vague character of natural sounds. It is this wildness of character which is one of the great charms of bell-music on a large scale, and which has caused it to be so much interwoven with the associations of men, both in real life and in imaginative literature.
Like the harp, the bell is prse-historic in its origin; nor would it serve much purpose here to speculate upon the probable origin, or earliest form of the bell, of which in fact we know nothing; or even to dwell on the very uncertain archæology of the instrument. The records of almost all nations of whose early history we know anything imply the use of bells in one shape or another; generally, it would seem, as a sign or proclamation, just as the railway bell, the church bell, and 'that tocsin of the soul, the dinner-bell,' are still used. But there can be no question that the real development of bells and bell-ringing into their highest form is due to the art and the ecclesiastical fervour combined of the middle ages. The influences which led to the development of bell-ringing and bell-founding were not dissimilar to those which led to the great development of architecture in the cathedral form. Not that either architecture or bells were necessarily connected with ecclesiastical predominance; but that the church being the great power and central influence of mediæval Europe, the art of the time was all drawn into its service, and thus it came to pass that bells having been, at a comparatively early period of the Christian era, introduced as an appendage to places of worship, their development, with all the art and science which the mediaeval workmen had at command, became almost inseparably connected with that of church architecture, and their sounds associated in an especial degree with church celebrations. The form of bell which may be said to have been perfected by mediæval bell-founders (for it has been accepted as a type upon which no essential or radical improvement can be made) is that shown in the following diagram, in which also the principal component parts of the bell are distinguished.
The elevation of the exterior of the bell explains itself; the section shows the relative thickness and shape of the metal; the thickest portion, the 'sound-bow,' A, against which the clapper strikes, is usually 1/12 th of the total diameter of the bell at the lip. The half-section marked No. 1 shows the old method of providing for the hanging of the bell and the attachment of the clapper; the loops called 'canons,' B, being cast on solid to receive the iron straps by which the bell is fixed to the stock, and the bolt, C, for attaching the clapper also cast solid on the inside of the bell. It is necessary that C should be well below the line of axis on which the bell swings, so as to describe an appreciable circle around the axis, otherwise there will be no leverage to drive the clapper, and it will not fly properly. The swing of the clapper is further ensured and accelerated by the small piece, D, called the 'flight,' cast on to the striking part to increase the impetus of the blow. Half-section No. 2 shows a method of hanging the bell and clapper recommended by Sir E. Beckett, and adopted in a good many instances by Mr. Taylor of Loughborough, in which canons are dispensed with, and a thick crown, E, is used with bolt holes through which the bell is bolted to the stock, and a larger hole in the centre through which the clapper-bolt is also fixed to the stock, instead of being cast on to the bell. The advantage of this plan is that the bell can easily be turned on the stock, the clapper-bolt (which is circular where it passes through the bell) remaining stationary, and thus the blow of the clapper can be directed against a new portion of the sound-bow, should the original striking place have become worn or show any tendency to crack.
The material of which bells are composed is a mixture of copper and tin, which in the old bells appear to have been used in the proportion of about 3 to 1. Modern experiment has given rise to the conclusion that, while this combination gave the best sound, and the proportion of tin might even be increased with advantage to the sound, this proportion represents the extreme amount of tin which can be used without the danger of rendering the metal brittle and liable to crack, and that in regard to this consideration a margin within that proportion of tin is safer. 22 of copper to 7 of tin was used for the Westminster bells in the Victoria Tower. Any considerably larger proportion of copper than this, on the other hand, has a tendency to render the metal too soft, and impair the brilliancy of its tone.
The conclusion that the special shape figured above, or something near it, is the best for a bell, has no basis that any one seems to know of except experience. It has been theoretically maintained that plain hemispherical bells ought to give the best and purest tone, but except on a small scale it is not found to be so; the result being either that the tone is very heavy and dead, or that when forced by hard striking it is unmusical and disagreeable to the ear. Sets of hemispherical bells have lately been made of larger size, and with more success than before; they require, however, to be fixed and struck, and not swung; their tone when not struck too heavily is not unpleasing, but quite inferior in power and brightness to that of a swung bell of the usual form. It is also to be noted, though this fact again is equally inexplicable, or at least unexplained, that large and small bells require somewhat differing shape and proportions to realise the best sound. That the proportionate thickness or weight of metal for producing the best results should be different for large and small bells, it is more easy to understand. For a large bell, such as 6-feet diameter, experience seems to give a thickness of 1/12 of the diameter as the best proportion. Smaller bells will bear a somewhat greater proportionate thickness, and the proportionate thickness—that is to say, the proportionate weight of metal to the note prouced—is always increased in a large peal, from the lower to the upper notes of the scale. The thinner the bell is in proportion to the weight of metal, it should be observed, the deeper is the pitch: so that if the same proportionate thickness were preserved in the treble as in the tenor of a peal, the former would have to be made of too small size and too little weight of metal to compete successfully with the tenor. By adding to the proportionate thickness of the treble, we are enabled to make it of larger size and heavier metal while preserving the high pitch. This effect of thickness on pitch is a thing to be borne in mind in ordering a peal of bells, and deciding what scale or pitch is to be adopted. The cost of the bells is in proportion to the weight of metal, and the question therefore is, given so much metal, in what form to cast it so as to get the best effect from it. This will often be best realised by not endeavouring to get too deep a tone from the peal; a peal tuned in the scale of E or of F may be equally cast with the same amount of metal, but will not be equally good, as either the E peal in that case must be too thin, or the F peal too thick. Where the amount of metal is limited, therefore, the higher pitch will give the best result, and enable the metal to be used to the best advantage.
The precise note which a bell of a certain shape, size, and weight will produce is almost a matter of experience; but the proportion between size and relative dimensions and pitch is capable of being approximately tabulated. The average modulus of the finest of the large bells of Europe, as between size and weight, is given by Sir E. Beckett (to whose work on Clocks and Bells the reader is referred for more detailed information on some of the points touched upon here), as 10 cwt. of metal for a bell 3 feet in diameter, and as the weight of metal varies as the cube of the diameter, a bell of 4 feet diameter would consume nearly 25 cwt., and one of 6 feet diameter 4 tons of metal. A bell of this last-named weight would, with the best and most effective disposition of the metal, give the note tenor C; and the pitch for other sizes may be deduced from this, on the rule that the number of vibrations per second in bells varies as (thickness)2 / diameter.
Where a set of bells are in precisely similar proportions throughout, their dimensions would be simply in an inverse ratio to the number of vibrations per second of the notes they were intended to sound. But as in practice the higher pitched bells are always made thicker in proportion to the diameter than the lower ones, for the reasons mentioned above, the problem cannot for practical purposes be stated in the simple form of inverse ratio. Bells, it may be observed, are tuned by turning out a small portion from the inner side of the thickest part or sound-bow, when they are too sharp, so as to reduce the thickness and thereby flatten them, or by similarly turning off a small portion from the edge of the rim, so as to reduce the diameter, when it is desired to sharpen them. This latter process, however, impairs the shape, and is apt also to injure the tone of the bell; and if the casting cannot be so accurately regulated as to give hope of ensuring correctness at first, it is better to let any excess be on the side of sharpness, which can be corrected without damaging the bell. In the case of large peals the plan has sometimes been followed of casting all the smaller bells a trifle thick, so that if the whole peal is not precisely in tune, the tuning may all fall on the smaller bells, which will be reduced in thickness till they are brought down to the pitch to range correctly with the larger ones. Bells are however now cast with considerable accuracy, and the turning out of a nearly perfect, or, as it is called, a 'maiden' peal, is not an uncommon occurrence; though it must be said that peals are not unfrequently so called which are not as perfectly in tune as they ought to be, but which are left untouched in order to claim the credit of being a 'maiden' set. This ought never to be allowed; in fact a much more rigorous standard ought to be maintained in tuning bells than is usual: the number of bells not properly in tune with each other which we hear is a constant annoyance to those whose ears can detect the falsity, and perhaps does something towards confirming other listeners in their deficiency of what is called 'ear.'
The casting of a large bell is an operation requiring considerable preparation and a great deal of nicety of workmanship. The first process is to form the model of the inside surface of the bell, or the core, which is done on a conical-shaped base of iron or brickwork; the clay, after being approximately modelled by hand, is brought to the correct mould by means of what is called a 'sweep,' which is a flat piece of hard wood with one of its edges cut to the section of the inside of the bell, and which is attached to a pivot fixed in the centre of the core, and then 'swept' round the clay until the model of the inside of the bell is correctly formed. The core is then thoroughly dried by heat, either by a fire lighted under it (if it is on a brick base), or by being placed bodily in an oven (if it is on an iron base). The next point is to obtain the outer shape of the bell, and its thickness. There are two ways of doing this. The method which used to be universally adopted was to make upon the core, after it was dried, a model of the thickness of the bell in clay, the outer shape of the bell being obtained by another sweep operating in the same way, and turning on the same centre as that which formed the inside shape; then upon this, when dry, to build a cover or cope, the inner side of which closely followed the outer shape of the bell. This cope, going like an extinguisher over the whole, was strengthened with haybands, or, in the case of large models, with pieces of iron worked into it, so that when made it could be bodily lifted off, the clay bell previously made on the core broken away, and the cope replaced, leaving between it and the core the precise shape and thickness of the bell. The difficulty however of getting a good external finish in this way must have been considerable. The method now usually employed is to dispense with the operation of making the clay 'thickness' altogether, and to have a metal cope larger than the size of the bell, and lined with clay, in which the external model of the bell is then formed by an inverted sweep, acting on the inside surface; the cope is then turned over the core, and the exact model of the bell is represented, of course, by the space between them. The direct action of the sweep secures a more finished exterior surface than with the old hand-made cope; and another advantage is that the iron cope can be bolted down to a plate below the core, so as to render the whole thing perfectly steady for the casting, and greatly facilitate the process of getting it into the sand. The mould which gives the shape of the top of the bell, with the clapper-ring and the ears or 'canons' for fixing the bell to the stock, is added to the model by a separate process, and the whole is then imbedded in the sand of the casting-room with the mouth down-ward, and the metal run in and left to cool.Bells have occasionally been used in the orchestra, though hardly in any sense which can justify their being included among orchestral instruments; since when used singly and sounded by swinging in the ordinary way, they are invariably intended to give what may be called 'local colour' to a dramatic scene; to suggest something beyond or apart from the orchestra, as the prison-bell in the 'Trovatore,' the goat-bell in 'Dinorah,' or the vesper-bell in Bennett's 'Paradise and the Peri' overture. Mozart has, however, used a frame of bells played by a keyboard like that of a pianoforte ('Glockenspiel') in the score of 'Die Zauberflöte,' to represent the effect of Papageno's bells which are visibly present in his head-dress, though actually played in the band. The same instrument has been used in a somewhat similar manner by one or two other operatic composers, but always for stage effect rather than for directly musical purposes. A recent idea of some English organ-builders has been the attachment of a scale of bells to an organ, which are sounded either alone or in combination with the ordinary stops on drawing a stop-head which brings them under the control of the keys; but the addition is completely out of keeping with the genius of the organ, and is available rather for 'sensational' effects than as a real addition to the proper range of the instrument. All these experiments only serve to confirm the opinion that bell-music does not belong to the region of musical art properly so called; and attempts to drag the bell from its proper sphere, and force from it an expression foreign to its nature, have never permanently succeeded.
[ H. H. S. ]