16. Trumpets sounded by flowing Water.
In the same manner as that just described the sound of trumpets can be produced. Insert into a carefully closed vessel the tube of a funnel reaching nearly to the bottom and soldered into the surface of the vessel; and, by its side,a trumpet, provided both with a mouth piece and bell, and communicating at its upper extremity with the vessel. If water be poured through the funnel, it will be found that the air contained in the vessel, as it is being driven out through the mouthpiece, will produce the sound of a trumpet.