ahead undisturbed with its work and to preserve a continuity in its investigations impossible to any public-detective center of the United States.

Scotland Yard's greatest difficulty in a man hunt is with the Continental criminal.

According to diplomatic custom it cannot communicate directly with the detective department in any foreign country. All communications must be made first to the foreign minister, who in turn communicates with the ambassador in London for his country. This ambassador takes the matter up with the British Secretary for Foreign Affairs, who finally turns it over to the Home Secretary, where it at last, in this roundabout method, reaches Scotland Yard. This very greatly complicates all criminal investigation attached to foreign affairs.

These international cases are the most incredible with which the detective centers have to contend.

A late chief of the Criminal Investigation Department of Scotland Yard says that one Sunday a physician of very high standing brought him the most extraordinary letter he ever saw. It had been picked up back of Portland Place and was written from the Chinese Embassy in London. The envelope requested the finder to take it at once to the physician's address. A hostler, who picked it up, carried out that direction.

The envelope contained a letter from Mr. Sun Yat Sen, Chinese reformer, (later president of the Chinese Republic), saying that he had been kid

naped as he passed the Chinese Embassy and was now confined within it; that the intention on the part of the Chinese officials was to drug him, convey him to the dock and ship him to China; that, being in the embassy he was constructively on Chinese territory and could not be interfered with by the English authorities; that if any difficulty should arise, as they had exterritorial authority over him, the Chinese would promptly decapitate him and end the controversy.

This communication seemed wholly incredible. Nevertheless it was precisely true. Mr. Sun Yat Sen was, in fact, a prisoner in the embassy; and it was only after long negotiations of great diplomatic delicacy that the Home Office was able to obtain his release.

Scotland Yard's method of arrest is usually direct; it is rarely by ruse or finesse. Once the man hunt is ended and the quarry rounded up, the constables force in and seize him. It is a method unusually dangerous.

Take, for example, the Houndsditch affair, in December, 1910. Here four desperate foreign cracksmen entered a house adjoining a jeweler's shop. They were at work with a crowbar, forcing the wall, when sounds were detected and the police notified. When they attempted to force the door the cracksmen emptied their pistols into the group of constables on the steps.

These desperadoes were afterward located in the second story of a house in Sidney Street. Here they

were besieged for a whole day, not only by the police force but also by a detachment of the First Battalion of the Scots Guards, and the house finally burned to the ground.

The police of New York were greatly amused at this all-day siege in the heart of London. But Scotland Yard showed by statistics that one was more apt to be shot on Broadway than in the province of Chihuahua during a Mexican revolution.

These Lithuanian desperadoes gave Scotland Yard no end of trouble; they were only to be taken after a pitched battle or running fight. If the final drama that began at Cheshunt Road, Tottenham, had come under the eye of an American spectator he would have believed that an enterprising motion-picture director was staging a thrilling "chasie." About ninethirty one Thursday morning a cashier got out of a motor car, with the wages for his factory employees in a bag. He was accompanied only by the chauffeur. Two men rushed out, fired several shots, snatched the bag of money and ran away with it.

Both of the robbers were armed. Several persons were winged and fell out of the man hunt. Presently the police from a neighboring station joined in and the running fight advanced along the bank of the River Lea. When the robbers reached Chingford Road they found a street car. They covered the motorman and conductor with their pistols and compelled them to drive on. The police got a pony cart and followed. The robbers shot the pony.

Presently another street car approached from the opposite direction; the police commandeered it, reversed it, and the chase continued. The two cars went away madly on parallel tracks, the robbers in one, the police in the other. Finally the robbers abandoned their car as the police car began to overtake them and made off in the direction of Woodford, where at last in the deeps of Epping Forest they died like the cornered heroes of a Yellow Saga.

This system of man hunting by hue and cry is apt to be a costly method. Like the direct form of arrest by forcible entry, it drives the trapped quarry into a resistance that otherwise he might have hesitated to present. This direct action and the method of following only the dominant clew are the distinguishing characteristics of Scotland Yard. They are illustrative of the English mind, which seizes only essential factors and drives through to its object on the shortest line.

So it happens that one finds the records of criminal trials crowded with convictions based on a single paramount item of circumstantial evidence, as in the Blight mystery, which Sir Ashley Cooper cleared up by showing that the assassin was left-handed; and the great Humphreys fraud, when a charter granted by Charles I to the Earl of Stirling was shown to be spurious because it contained margins in red ink, when red ink was not in use before 1780 in England.

We shall see how this method of Scotland Yard compares with that of other great detective centers.

CHAPTER II

FRENCH METHODS OF CRIMINAL INVESTIGATION

WHEN an authority on criminal psychology

W

at Gottingen printed his learned thesis on the fourth dimension, the Prefect of Police of Paris sent him word that, though the existence of the fourth dimension might be involved in doubt, if the professor would come to France he would take great pleasure in showing him a thing that had only two dimensions. The criminologist replied that the invitation of the Prefect was courteous, but his suggestion unthinkable. One could postulate a fourth dimension, but by no possible effort was the human consciousness able to imagine a thing of two dimensions alone. Length, breadth and thickness were essential to all mental conceps of the material world.

The Prefect renewed his invitation and the criminologist traveled to Paris. Whereupon, on a bright sunny morning, he was taken up the Champs Elysees and shown the shadow of the Arc de Triomphe! It lay in the brilliant sun, clearly defined in its length and breadth, but not even a psychologist from Gottingen could discover that it possessed any thickness.