Supposing the word to be orange. He begins with four taps, and the confederate, who is all attention, knows that the word begins with the fourth vowel, O.
The wizard, flourishing his wand, remarks with extreme innocence:
“Rather fatiguing work, as you perceive.”
The confederate says to himself R.
One tap is the next sound for A.
And some sentence such as—
“No one can imagine the mental strain,” supplies the letter N to his alert companion.
The wizard’s query, voiced in a mocking tone,
“Getting near it?” supplies the letter G.
A few more imaginary pictures, and two taps, which represent letter E, and the confederate with an air of profound relief wipes his brow and declares confidently that the word is orange.