_b b_ represent two of the legs of the frame, one of which, as well as half the rail, is made into a tube, the end of which opens immediately opposite to the centre of the trumpet. This hole is very small, and concealed by mouldings; the other end communicates by a tin pipe, _p p_, which passes, in a concealed manner, along the floor of the room, into an adjoining closet, where the confederate is concealed. It is evident that any sound, directed into the mouth of the trumpet, will be immediately reflected back to the orifice of the tube, and distinctly heard by a person who places his ear to the mouth of the funnel _m_; while the answer returned by him, travelling along the tin funnel, _p p_, will issue from its concealed orifice, and striking upon the concave surface of the trumpet, be returned to the ear as an echo, and thus appear as if it had proceeded from the interior of the ball. The vicar observed, “that this deception of the _Invisible Girl_, which had formerly created so much interest, was little more than the revival of the old and well-known mechanism of the _speaking bust_, which consisted of a tube, from the mouth of a bust, leading to a confederate in an adjoining room, and of another tube to the same place, ending in the ear of the figure; by the latter of which, a sound whispered in the ear of the bust was immediately carried to the confederate, who instantly returned an answer by the other tube, ending in the mouth of the figure, which therefore appeared to utter it. The Invisible Girl,” continued the vicar, “evidently only differs from that contrivance in this single circumstance, that an artificial echo is produced by means of the trumpet, and thus the sound no longer appears to proceed in its original direction.” “Your remark is perfectly correct, my dear vicar,” said Mr. Seymour. Tom Plank, with an air of self-satisfaction, at this moment emerged from his retreat, and enquired whether his performance had not met with the approbation of his employer. “Gentlemen,” said Tom Plank, “as I am now fully satisfied that any plan of propelling live and dead luggage through funnels can never succeed, I propose to employ tubes for conveying sounds to a great distance, so as to do away with the use of telegraphs?” “Why that plan is more practicable, but less novel, than the one you have just abandoned,” answered Mr. Seymour. “At the latter end of the last century, a man of the name of Gautier conceived a method of transmitting articulate sounds to an immense distance. He proposed the construction of horizontal tunnels that should widen at their extremities, by means of which the ticking of a watch might be heard more distinctly at the distance of two hundred feet than when placed close to the ear. I think he calculated that a succession of such tunnels would transmit a verbal message nine hundred miles in an hour.”(50)