Question

In the room below corresponding to the one above was placed the person who was to answer, with his mouth to the tube, and the voice, as in an ear-trumpet, passed from above downwards, and from below upwards, the words coming clearly and distinctly; it was impossible, thus, to detect the trick.

Accepted Answer

En el aposento de abajo correspondiente al de arriba se ponía el que había de responder, pegada la boca con el mesmo cañón, de modo que, a modo de cerbatana, iba la voz de arriba abajo y de abajo arriba, en palabras articuladas y claras; y de esta manera no era posible conocer el embuste.

Back	In the room below corresponding to the one above was placed the person who was to answer, with his mouth to the tube, and the voice, as in an ear-trumpet, passed from above downwards, and from below upwards, the words coming clearly and distinctly; it was impossible, thus, to detect the trick.
Front	En el aposento de abajo correspondiente al de arriba se ponía el que había de responder, pegada la boca con el mesmo cañón, de modo que, a modo de cerbatana, iba la voz de arriba abajo y de abajo arriba, en palabras articuladas y claras; y de esta manera no era posible conocer el embuste.

De El Abajo Y En Arriba La Modo