Drum (machine)

“ Another organic difficulty existing in drum machines was the dangerous possibility of the car—or the counterweight, whose cables often wound on the drum—being drawn past the normal top limit and into the upper supporting works. ”

“ By placing each group of threads to be wound in the slit of a rotating drum, it is drawn quickly to and fro and coiled upon a spool. If solid instead of split drums be used, the guides for all the threads on one side of a machine are attached to a bar, which is traversed by a cam placed at one end of the frame. Or independent mechanism may be provided throughout for treating each group of threads to be wound. The bobbins or tubes may be filled from cops, ring spools or hanks, but a stop motion is required for each thread, which will come into operation immediately a fracture occurs. ”

“ It is necessary to place the print upon the drum in such a manner that the stylus draws away from the edge of the lap and not towards it, and the metal prints should be of such a size that when placed round the drum of the {19}machine a lap of about 3/16ths of an inch is allowed. ”

“ The roll is generally caused to rotate at a speed of about 230 revolutions per minute, causing the water and rags to circulate in the engine and to be constantly under the action of the knives. In the other division F F of the trough is the drum-washer H, which, being covered with fine gauze wire, allows the water to enter, but keeps back the fibrous material. The ends of the drum are formed of two discs of wood, generally mahogany, upon which the coarse gauze is fastened as a backing, and this is covered with the fine wire gauze. ”

“ Anyone who has seen the band of the Life Guards must have admired (as I do) the splendid personage who plays the kettle-drums. These are not of the ordinary drum-form, being hemispherical instead of cylindrical, and having but a single membrane. They have a right to be called musical instruments since their pitch is alterable: [96d] I have often admired p. 97the drummer in an orchestra tuning his instrument at a change of key. One sees him leaning over his children like an anxious mother until he gets his large babies into the proper temper. ”

“ As the chest rises and falls in breathing, the levers press more and less upon the surface of the drum; and this varying pressure on the air inside the drum is transmitted from the drum through an air-tight tube to a little pencil which it drops and lifts. The pencil, as it rises and falls, touching always a sheet of smoked paper traveling over a cylinder on the recording device, traces a line whose rising strokes represent accurately the drawing of air into the chest and whose falling represents its expulsion. ”

“ Bentley and Jackson's Drum-Washer.—This drum-washer, for use in the rag-engine, is shown in Fig. 43. It has cast-iron ends, strong copper buckets, shaft, stands, lifting-gear, and driving-wheel, but instead of the drum being covered with the ordinary strong brass backing-wire, it is covered with their improved "honey-comb" backing-plates, over which the fine wire is wrapped as usual. The honey-comb backing consists of tough rolled brass or copper plates, curved to suit the diameter of the drum, and secured to its ends by cross-bars. ”

“ The head is drawn by an endless cord passing over pulleys from the outside to the inside of the drum, where it goes over two nuts, having each two pulleys. These nuts approach and recede from each other by means of a horizontal screw, nearly as long as the diameter of the drum, the handle of which comes just outside the shell, and is turned by the performer whenever he requires to tune the drum. A spring indicator shows the degree of tension of the cord, and consequently the note which the drum will give, so that the performer may tune his instrument by the eye instead of the ear. ”

“ The drum A, which revolves easily on a vertical axis, is of metal, and is provided with a large number of fine perforations on its peripheral surface. It can be rotated at high speed by means of the crank f and pinions d, e, or by the fast-and-loose pulley a b connected with a source of power. ”

“ To tune drums of the ordinary construction, a key has to be applied successively to each of the several screws that serve to tighten or loosen the head. In French-made drums there is a fixed T-shaped key-head to each screw. But even then it takes some time to effect a change, whence several attempts have been made to enable the performer to tune each drum by a single motion instead of turning seven or eight screws. ”

“ To prevent any of the charge from being projected over the rim of the drum, the upper edge is turned over so as to leave only a comparatively small opening at the top. The lower end of the drum shaft carries a strong steel spindle, which must be carefully machined and enable the drum to revolve as easily as possible. ”

“ Two vats are to be supplied with paper stuff as usual; in which two hollow barrels or drums are made to revolve upon axles driven by any first mover; an endless felt is conducted by guide rollers, and brought into contact with the drums; the first drum gives off the sheet of paper pulp from its periphery to the felt, which passing over a pressing roller, is conducted by the felt to that part of a second drum which is in contact with another pressing roller. ”

“ The drum may carry a crank and shaft, which works the spur-wheel and toothed bands as already described, so that no matter at what stage in the revolution of the drum an upward or downward stroke may be stopped, the motion will still be communicated in a continuous rotary form to the fly-wheel. ”

“ The engine is direct-acting, the drums making one revolution for each double stroke. In geared hoists the drums are on a separate shaft, driven from the crank-shaft by tooth or friction gearing, and make one revolution for, say, 4 or 5 double strokes. The hoisting speed is therefore slower, and as less engine power is required for a given load the cylinders are smaller, though making more strokes per minute. Large and powerful geared hoists are not uncommon. The dimensions of the drum depend on the hoisting speed desired and the depth of shaft or length of rope to be wound. ”

“ The paying-out drum is controlled by an Appold's friction brake, which is simply a belt or strap of iron with blocks of wood studded to it clasping the periphery of the drum and restraining its revolution by the friction of the wooden blocks. The tighter the belt is made to clasp the drum, the greater the friction on the drum, and the greater the force required to make it revolve. After passing several times round the drum, so as to get a good hold of it, the cable passes through the dynamometer to the sheave or grooved pulley projecting from the stern, and from thence it passes to the water. ”

“ As before, we have a hammer vibrating backwards and forwards in response to pulls from a magnet, which is magnetized and demagnetized by stopping and starting an electric current. In the case of the induction coil, the hammer is only a means whereby the current is broken and started again with great rapidity, and in the case of the trumpet the vibrator is used to make the noise by its vibration, but in this instrument we must have a bona fide hammer, which must be able to beat the drum, and thus cause a stirring and martial sound. ”

“ The roll is produced by striking two blows alternately with each hand quite regularly and very rapidly, the result being a rattling tremolo. This roll (“daddy-mammy”) is very difficult to acquire, and requires long practice. The side drum can be muffled by loosening the snares or by inserting a piece of silk or cloth between the snares and the parchment. An impressive effect is produced by a continued roll on muffled drums in funeral marches. ”

“ In the drummer boys’ quarters, drums were used for writing stands and card playing tables, while often a checkerboard would be sketched on the head of the drum and for men buttons would be used, and with plenty of rations we managed to be quite comfortable except when on picket. ”

“ Some drums are shallow, some deep, and each is made by the individual player, who tunes it by heating the drum until the metal is soft, and then pounding it until he acquires the exact tone he desires. ”

“ Drums are, with the exception of kettle drums, indeterminate instruments, hardly, in themselves, to be regarded as musical, and yet important factors of musical and especially rhythmic effect. The kettle drum is a caldron, usually of brass or copper, covered with a vellum head bound at the edge round an iron ring, which fits the circle formed by the upper part of the metal body. ”

“ One end of each drum is loose, and falls inwards upon the opposite end, upon which it lies flat, thus giving space for the introduction of another drum, a size smaller. Across the loose end, and parallel to it, is fixed a wire, forming a handle whereby the performer may lift311 the drum out of the hat, the act of doing so raising the end into its proper position, and a wire rim round the inside of each drum preventing the loose end being drawn out altogether. Each drum is taken out with the loose end upwards ”

“ At regular intervals in the two large hoops are bored holes through which passes an endless cord stretched in zig-zag round the cylinder and connecting the two hoops. The tension of the vellum is controlled by means of leather braces which are made to slide up and down the zig-zag of cord, slackening or tightening the large hoops, and with them the vellum, at the will of the performer. Systems of rods and screws are also used for the purpose. The bass drum is mounted on a stand when used in the orchestra. ”

“ The drum, roughly speaking, is the oldest musical instrument. It is of great interest to us inasmuch as it still holds a place of honor in the modern orchestra. It is the king of the group of percussion instruments whose object it is, not to produce a tone, but an accent.
No tribe of savages has been discovered but what is possessed of a drum of some sort. The most usual form of construction of the primitive drum has been that of a section of tree trunk, hollowed out, and covered with skin at each end. Certain trees, such as the bread-fruit tree or the bamboo, render this peculiarly feasible. ”

“ The side drum, so called because it is worn at the side, is struck in the centre by two small wooden sticks with elongated heads or knobs of hard wood, producing a hard rasping sound when the drum is played singly and in close proximity to the hearer; when, however, several drums are played simultaneously or with other instruments the effect is brilliant and exhilarating. ”

“ A delicate lever rests on the membrane of the other drum, and the end of this lever is armed with a delicate point which touches a revolving cylinder covered with smoked paper. On this cylinder the tuning-fork also simultaneously traces its time-record. Now, as both drums, and the tube which connects them, form an air-tight space, it follows that any depression, given to the membrane which touches the moving surface, will compress the air in this drum, in the connecting tube, and in the drum which carries the delicate lever. ”

“ In the first place, the apparatus is very costly, and, secondly, they are unpleasantly liable, from the nicety of their mechanism and the absolute necessity of perfect electrical connection in all their parts, to hang fire at the critical494 moment, and leave the operator in a very embarrassing position. Imagine the feelings of a performer who, having just introduced his wonderful drum, which is to display unheard-of oracular powers, finds that the instrument remains as mute as the celebrated harp in Tara’s halls, and refuses to bear out, in the smallest degree, his grandiloquent assertions. ”

“ By running double wires from battery and press to the trumpet, and another double wire from battery and press to the drum, you can arrange matters so that when you put one press down the trumpet works, and when the other press is put down the drum works. ”

“ The only musical instrument in use among these people is the universal drum505 or tambourine (kĕlyau) , consisting of a membrane stretched over a hoop with a handle on one side, and used from Greenland to Siberia. It is always accompanied by the voice singing or chanting. The player holds the handle in his left hand with the membrane away from him, and strikes alternately on each side of the rim with a short heavy piece of ivory, or a long slender wand, rotating the drum slightly at the same time to meet the stroke. ”

“ The lateral positions of the projectable gear teeth correspond to the spacing of the type-wheels, and an intermediate gear G, meshing with each type, or register wheel, is loosely mounted on the shaft H, interposed between the said wheels and the actuating drum E, so that when the drum is revolved by the crank provided for that purpose, the gear teeth protruding from the drum will engage the intermediate gears G, and turn them and their type or register wheels as many of their ten points of rotation as have been set up in their respective orders of the setting devices of the drum. ”

“ The fingers of the hand which holds the instrument, striking only near the hoop, produce higher sounds than the other hand, which strikes in the centre. A tambourine of a larger and more simple kind than that here described, without the metal plates, is often used by the lower orders. The other instrument alluded to in the commencement of this paragraph is a kind of drum, called dar'abook'keh. ”