Regardless of the mother, Evelyn ran to the telephone and notified the police. They responded promptly, three detectives and two uniformed officers. The threatening letter was placed in their hands, and one of them laid its contents before his chief by 'phone, a general alarm was sent out.
While the uniformed men searched the house again from attic to cellar the two other plain clothes men searched outside. Together they went over the ground, but the surface of the snow was unbroken save for their own footprints and the paved path. From the front wall, which faced the street, the detectives walked slowly back, one on each side of the house, searching in the snow for some trace of a footprint.
There was nothing to reward this vigilance, and they met behind the house. Each shook his head. Then one stopped suddenly and pointed to the snow which lay at their feet and spreading away over the immense back yard. The other detective looked intently then stopped and stared.
What he saw was the footprint of a child-a baby. The tracks led straight away through the snow toward the back wall, and without a word the two men followed them, one by one; the regular toddling steps of a baby who is only fairly certain of his feet. Ten, twenty, thirty feet they went on in a straight line and already the detectives saw a possible solution. It was that Baby Blake had wandered away of his own free will.
Then, as they were following the tracks, they stopped suddenly astounded. Each dropped on his knees in the snow and sought vainly for something sought over a space of many feet, then turned back to the tracks again.
"Well, if that--" one began.
The footprints, going steadily forward across the yard, had stopped. There was the last, made as if Baby Blake had intended to go forward, but there were no more tracks-no more traces of tracks-nothing. Baby Blake had walked to this point, and then--
"Why he must have gone straight up in the air," gasped one of the detectives. He sank down on a small wooden box three or four feet from where the tracks ended, and wiped the perspiration from his face.
II.
"All problems may be reduced to an arithmetical basis by a simple mental process," declared Professor Augustus S. F. X. Van Dusen, emphatically. "Once a problem is so reduced, no matter what it is, it may be solved. If you play chess, Mr. Hatch, you will readily grasp what I mean. Our great chess masters are really our greatest logicians and mathematicians, yet their efforts are directed in a way which can be of no use save to demonstrate, theatrically, I may say, the unlimited possibilities of the human mind."
Hutchinson Hatch, reporter, leaned back in his chair and watched the great scientist and logician as he pottered around the long workbench beside the big window of his tiny laboratory. It was here that Professor Van Dusen had achieved some of those marvels which had attracted the attention of the world at large and had won for him a long list of honorary initials.
Hatch doubted if the Professor himself could recall these-that is beyond the more common ones of Ph. D., LL. D., M. D., and M. A. There were strange combinations of letters bestowed by French, Italian, German and English educational and scientific institutions, which were delighted to honor so eminent a scientist as Professor Van Dusen, so-called The Thinking Machine.
The slender body of the scientist, bowed from close study and minute microscopic observation, gave the impression of physical weakness-an impression which was wholly correct-and made the enormous head which topped the figure seem abnormal. Added to this was the long yellow hair of the scientist, which sometimes as he worked fell over his face and almost obscured the keen blue eyes perpetually squinting through unusually thick glasses.
"By the reduction of a problem to an arithmetical basis," The Thinking Machine went on, "I mean the finding of the cause of an effect. For instance, a man is dead. We know only that. Reason tells us that he died naturally or was killed.
"If killed, it may have been an accident, design or suicide. There are no alternatives. The average mind grasps those possibilities instantly as facts because the average mind has to do with death and understands. We may call this primary reasoning instinct.
"In the higher reasoning which can only come from long study and experiment, imagination is necessary to supply temporarily gaps caused by absence of facts. Imagination is the backbone of the scientific mind. Marconi had to imagine wireless telegraphy before he accomplished it. It is the same with the telephone, the telegraph, the steam engine and those scores of commonplace marvels which are a part of our everyday life.
"The higher scientific mind is, perforce, the mind of a logician. It must possess imagination to a remarkable extent. For instance, science proved that all matter is composed of atoms-the molecular theory. Having proven this, scientific imagination saw that it was possible that atoms were themselves composed of more minute atoms, and sought to prove this. It did so.
"Therefore we know atoms make atoms, and that more minute atoms make those atoms, and so on down to the point of absolute indivisibility. This is logic.
"Applied in the other direction this imagination-really logic-leads to amazing possibilities. It would grade upward something like this: Man is made of atoms; man and his works as other atoms make cities; cities and nature as atoms make countries; countries and oceans as atoms make worlds.
"Then comes the supreme imaginative leap which would make worlds merely atoms, pin point parts of a vast solar system; the vast solar system itself merely an atom in some greater scheme of creation which the imagination refuses to grasp, which staggers the mind. It is all logic, logic, logic."
The irritated voice stopped as the scientist lifted a graded measuring glass to the light and squinted for an instant at its contents, which, under the amazed eyes of Hutchinson Hatch, swiftly changed from a brilliant scarlet to a pure white.
"You have heard me say frequently, Mr. Hatch," The Thinking Machine resumed, "that two and two make four, not sometimes, but all the time-atoms make atoms, therefore atoms make creations." He paused. "That change of color in this chemical is merely a change of atoms; it has in no way affected the consistency or weight of the liquid. Yet the red atoms have disappeared, eliminated by the white."
"The logic being that the white atoms are the stronger?" asked Hatch, almost timidly.
"Precisely," said The Thinking Machine, "and also constant and victorious enemies of the red atoms. In other words that was a war between red and white atoms you just witnessed. Who shall say that a war on this earth is not as puny to the observer of this earth as an atom in the greater creation, as was that little war to us?"
Hatch blinked a little at the question. It opened up something bigger than his mind had ever struggled with before, and he was a newspaper reporter, too. Professor Van Dusen turned away and stirred up more chemicals in another glass, then poured the contents of one glass into another.
Hatch heard the telephone bell ring in the next room, and after a moment Martha, the aged woman who was the household staff of the scientist's modest home, appeared at the door.
"Some one to speak to Mr. Hatch at the 'phone," she said.
Hatch went to the 'phone. At the other end was his city editor bursting with impatience.
"A big kidnapping story," the city editor said. "A wonder. I've been looking for you everywhere. Happened tonight about 6 o'clock-It's now 8:30. Jump up to Lynn quick and get it."
Then the city editor went on to detail the known points of the mystery, as the police of Lynn had learned them; the child left alone for only two or three minutes, the letter threatening kidnapping, the demand for $10,000 and the footsteps in the snow which led to-nothing.
Thoroughly alive with the instinct of the reporter Hatch returned to the laboratory where The Thinking Machine was at work.
"Another mystery," he said, persuasively.
"What is it?" asked The Thinking Machine, without turning.
Hatch repeated what information he had and The Thinking Machine listened without comment, down to the discovery of the tracks in the snow, and the abrupt ending of these.
"Babies don't have wings, Mr. Hatch," said The Thinking Machine, severely.
"I know," said Hatch. "Would-would you like to go out with me and look it over?"
"It's silly to say the tracks end there," declared The Thinking Machine aggressively. "They must go somewhere. If they don't, they are not the boy's tracks."
"If you'd like to go," said Hatch, coaxingly, "we could get there by half-past nine. It's half-past eight now."
"I'll go," said the other suddenly.
An hour later, they were at the front gate of the Blake home in Lynn. The Thinking Machine saw the kidnappers' letter. He looked at it closely and dismissed it apparently with a wave of his hand. He talked for a long time to the mother, to the nurse, Evelyn Barton, to the servants, then went out into the back yard where the tiny tracks were found.
Here, seeing perfectly by the brilliant light of the moon, The Thinking Machine remained for in hour. He saw the last of the tiny footprints which led nowhere, and he sat on the box where the detective had sat. Then he arose suddenly and examined the box. It was, he found, of wood, approximately two feet square, raised only four or five inches above the ground. It was built to cover and protect the main water connection with the house. The Thinking Machine satisfied himself on this point by looking inside.
From this box he sought in every direction for footprints-tracks which were not obviously those of the detectives or his own or Hatch's. No one else had been permitted to go over the ground, the detectives objecting to this until they had completed their investigations.
No other tracks or footprints appeared; there was nothing to indicate that there had been tracks which had been skillfully covered up by whoever made them.
Again The Thinking Machine sat down on the box and studied his surroundings. Hatch watched him curiously. First he looked away toward the stone wall, nearly a hundred feet in front of him. There was positively no indentation in the snow of any kind so far as Hatch could see. Then the scientist looked back toward the house-one of the detectives had told him it was just forty-eight feet from the box-but there were no tracks there save those the detectives and Hatch and himself had made.
Then The Thinking Machine looked toward the back of the lot. Here in the bright moonlight he could see the barn and the clump of trees, several inside the enclosure made by the stone wall and others outside, extending away indefinitely, snow laden and grotesque in the moonlight. From the view in this direction The Thinking Machine turned to the other stone wall, a hundred feet or so. Here, too, he vainly sought footprints in the snow.
Finally he arose and walked in this direction with an expression of as near bewilderment on his face as Hatch had ever seen. A small dark spot in the snow had attracted his attention. It was eight or ten feet from the box. He stopped and looked at it; it was a stone of flat surface, perhaps a foot square and devoid of snow.
"Why hasn't this any snow on it?" he asked Hatch.
Hatch started and shook his head. The Thinking Machine, bowed almost to the ground, continued to stare at the stone for a moment, then straightened up and continued walking toward the wall. A few feet further on a rope, evidently a clothes line, barred his way. Without stopping, he ducked his head beneath it and walked on toward the wall, still staring at the ground.
From the wall he retraced his steps to the clothes line, then walked along under that, still staring at the snow, to its end, sixty or seventy feet toward the back of the enclosure. Two or three supports placed at regular intervals beneath the line were closely examined.