to inscribe on the top card the first letter of his epistle; on the next the second; on the next the third -and so on until the pack is exhausted, when, of course, he will have written fifty-two letters. He now shuffles the pack according to a preconcerted plan. For example, he takes three cards from the bottom and places them at the top; then one from the top, placing it at the bottom-and so on for a given number of times.

"This done, he again inscribes fifty-two characters as before, proceeding thus until his epistle is written. The pack being received by the correspondent, he has only to place the cards in the order agreed on for commencement, to read, letter by letter, the first fiftytwo characters as intended. He has then only to shuffle, in the manner prearranged for the second perusal, to decipher the series of the next fifty-two letters and so on to the end."

Another ingenious device, used by the Germans in their system of espionage, is the cipher map, or what is sometimes called the spy landscape code.

This consists in making what appears to be a little harmless amateur sketch of some unimportant landscape. There would be trees, hedges, bushes, telegraph poles and lines, fences, little streams, and the like. The sketch would be made by a German secret agent, but it would appear to be simply such a sketch as a gentleman walking in the country might make, for his own pleasure, of some little view that pleased him. It would under no circumstances show anything

relating to a military affair; but, in fact, this harmless sketch would be a complicated cipher.

It would be made in accordance with a prearranged pictorial code, and would be, in fact, a sketch of an important fortification or of some military base.

The very simplicity of the methods used by the German Secret Service threw the whole British Empire into anxiety at the opening of the war.

CHAPTER XIV

CODES AND SIGNS OF THE UNDERWORLD

NE summer morning a man of middle age, with the stooped shoulders of a scholar and

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wearing thick myopic glasses, was strolling along a street of Monte Carlo, in that beautiful portion of the city above the Casino. On one side of him were the gardens, famed everywhere for their wonderful color scheme; and on the other were the great hotels, unequaled in Europe for their extravagant luxury.

As the stranger descended along the narrow paved street toward the Casino he noticed some curious signs written in chalk on the end of a stone step before one of the great hotels. These signs consisted of the figure six with an oblique stroke after it, followed by the figure two, a small, accurately drawn square, a cross and a curious round-bottomed V (Fig. 1). The stranger called a neighboring gendarme and directed his attention to the signs.

"Do you know what these chalk marks mean?" he said.

The gendarme shrugged his shoulders.

"Why should I bother to know?" he replied. "It's the work of some idle urchin."

The scholarly stranger regarded him for a moment through his thick myopic glasses. "And so," he said, "it is with this degree of intelligence that you undertake to guard a city that is the Mecca of all criminal adventurers.

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FIG. 1.

THE MONTE CARLO MYSTERY, OR
WHAT HAPPENED IN ROOM 66

"My friend," he continued, "this inscription is in the cabalistic signs of the most notorious criminal organization operating in the south of Europe. I shall translate it for you. The figure 6 followed by the long oblique stroke and the figure two are to be read as two sixes; that is to say, the number sixtysix, and are meant to indicate Room Number Sixtysix in this hotel. This means that some criminal adventure has taken place in Room Number Sixty-six. Let us see if we are told the nature of this adventure." He paused and indicated with the tip of his walking stick the little square drawn in chalk.

"That sign," he said, "stands for bank notes. It means that bank notes have been stolen from Room