from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun obsolete, rare An
instrumentfor compoundingthe resultantof two parallel, simple, harmonic waves.
from Wiktionary, Creative Commons Attribution/Share-Alike License
Acoustics were represented by an electro-magnetic brake siren of Mr. Bourbouze; Konig's apparatus for the synthesis of sounds; and Mr. S.P. Thompson's cymatograph -- a pendulum apparatus for demonstrating the phenomena of beats.