Drum

(drum.) [From Icel. thr uma, thunder.] (Mus.) A military musical instrument, commonly made of thin cylinders of wood, hollow within, and covered at the ends with sheets of vellum, which may be stretched or slackened at pleasure by means of small cords and sliding knots; it is beat upon with a pair of short sticks, one in each hand of the performer. Kettle-drums are hollow hemispheres made of bra , and are used in pairs; one of them being tuned to the key-note, and the other to the fifth of the key. Small D., hanging from the drummer's belt at the side, and beaten with the cha made or roulade, are styled side-drums. The instrument is of Eastern origin, and is believed to have been introduced into Europe by the Saracens:- the drum-major of a regiment of soldiers is the chief drummer, or the person who usually marches in front of the band giving the time by the motions of the baton he carries.-(Arch.) The upper part of a cupola, usually that below the dome; the term, too, is sometimes given to the base or solid part of the Composite and Corinthian capitals.(Anat.) The hollow part of the ear, behind the membrane of the tympanum; which latter is a tense membrane closing the external pa age of the ear, and receiving the vibrations of the air.-(Mach.) A hollow cylinder which, fixed in position on a shaft, communicates motion to another shaft by means of a revolving leather or gutta-perch a band. [s. 304]