WHISPERING GALLERIES.
As a rule a smooth-walled room of an elliptical shape will be found most probably gifted in this mysterious way.
THE INTELLIGENT ECHO.
Find a building, with a wall at an angle where an obstacle will send the voice from the one side around to the other instead of reflecting it as an echo. Then have a friend able to imitate voices concealed round the corner, so that, when your victim calls out, “Who are you?” the answer will come, apparently from echo, in the questioner’s own voice, “I, A or B, of course.”
TO SHIVER GLASSES BY SINGING.
It is known that glasses may be broken by the note, powerfully sounded, which is that given when it is struck, or the octave of that note. Thin and convex glasses are best. But, to make sure, nick or scratch the object with a diamond to start the fracture. A trumpet will not succeed while a violin will.
THE WOODEN HARMONICON.
On a firm stand erect a three-inch soft wood board, a yard high and half a yard broad, in which stand twenty deal rods. The longest should be about five feet. The ones representing semi-tones should be painted a different colour from the others, which can be left plain.
Rub the fingers in rosin-dust and set the rods vibrating with friction, and you will have a manageable instrument, sweet and expressive.