Note 40 — Chapter X · A CURIOUS EFFECT IN ACOUSTICS.
Professor Hoffmann translation
The deal rods at the Polytechnic were forty feet in length, and passed through two intervening stories of the building. A still more striking effect was obtained by transmitting (by the aid of a single harp) a vocal quartette, the performers holding their faces down as close as possible to the sounding-board of a piano. The absurdity of their position was occasionally too much for the gravity of the singers, and the quartette came to an abrupt conclusion amid peals of laughter, which were faithfully transmitted by the harp to the astonished audience.—Ed.