Beatings. Those regular pulsative heavings, or swellings of sound, produced in an organ, by pipes of the same key, when they are not exactly in unison, i. e., when their vibrations are not perfectly equal in velocity ; not simultaneous and coincident ; which, as Mr. Emerson observes occasions a repetition of noises like waw, aw, aw, wee, or ya, ya, ya, ya; these are called beats by Dr. Robert Smith, Mr. Emerson, and we believe every other mathematical writer that notices the phenomena. Earl Stanhope, in a letter in the "Philosophical Magazine," vol. xxviii. page 1.50, has labored to make a distinction between the meaning of beats and beatings, in order to identify the former with the pulses or VIBRATIONS of the sounds themselves, and to denominate the above

phenomenon by the exclusive use of the term beatings.