All this is highly mysterious, and is the result of a very ingenious mode of signaling which may be thus explained.
As soon as Professor B raises his eyes to Mlle. C they both start counting to themselves, and the instant he drops his eyes they cease. This has been practiced over and over again until they have learned to count exactly at the same speed. The result is that when the Professor has counted five, let us say, Mlle. C has counted five also, and so with any number.
The alphabet is then coded with numbers according to the following system.
| 1 | 2 | 3 | 4 | 5 | 6 | |
|---|---|---|---|---|---|---|
| 1 | F | E | D | C | B | A |
| 2 | G | H | I | J | K | L |
| 3 | R | Q | P | O | N | M |
| 4 | S | T | U | V | W | X |
| 5 | — | — | — | — | Z | Y |
The letters are represented by the vertical figures on the left and the horizontal figures on the top, and by this ingenious means are communicated.
To signal the letter A the Professor would glance up at Mlle. C, count one, and then glance down again; he would then look up and count six and lower his eyes once more.
Supposing that some lady had lent a diamond ring, the process would be the following:—
(The letter U shows when the Professor raised his eyes, and the letter D when he lowered them. The dots designate the numbers he would count in the interval.)
Prof.—(without speaking). U . . . D, U . D = R, U . . D, U . . . D = I, U . . . D, U . . . . . D = N, U . . D, U . D = G.
Mlle.—You have a ring in your hand.