A system of natural philosophy, designed for the use of schools and academies (1845)
Moffat, J[ohn] M. [from old catalog] · Philadelphia, E. C. Biddle · leaf 275
s of the frame, and meeting in a central point. Thehollow copper ball, M, with four trumpets, T, T, issuing from it How may polyphonous echoes in pipes and mines be explained ? To what useful purpose may the conduction of sound by long tubes beapplied ? What instances of ingenious deception have… … at right angles, hung in the centre of the frame, being connectedwith the wires alone by four narrow ribbons, D, D. Any questionor observation uttered in a low voice close to the open mouth ofone of the trumpets elicited a reply which might be heard fromall of them, the sound being perfectly…
Physics
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
