One of the requirements, and one to which an unusually large percentage of the class time was devoted throughout the four years, was freehand drawing. Tesla detested the subject almost to the point of open rebellion, and his marks were accordingly very low, but not entirely owing to a lack of ability.

Tesla was left-handed as a boy, but later became ambidextrous. Left-handedness was a definite handicap in the freehand-drawing studies, but he could have done much better work than he actually produced and would have gotten higher marks if it were not for a piece of altruism in which he engaged. A student whom he could excel in drawing was striving hard for a scholarship. Were he to receive the lowest marks in freehand drawing, he would be unable to obtain the scholarship. Tesla sought to help his fellow student by intentionally getting the lowest rating in the small class.

Mathematics was his favorite subject and he distinguished himself in that study. His unusual proficiency in this field was not considered a counterbalancing virtue to make amends for his lack of enthusiasm for freehand drawing. A strange power permitted him to perform unusual feats in mathematics. He possessed it from early boyhood, but had considered it a nuisance and tried to be rid of it because it seemed beyond his control.

If he thought of an object it would appear before him exhibiting the appearance of solidity and massiveness. So greatly did these visions possess the attributes of actual objects that it was usually difficult for him to distinguish between vision and reality. This abnormal faculty functioned in a very useful fashion in his school work with mathematics.

If he was given a problem in arithmetic or algebra, it was immaterial to him whether he went to the blackboard to work it out or whether he remained in his seat. His strange faculty permitted him to see a visioned blackboard on which the problem was written, and there appeared on this blackboard all of the operations and symbols required in working out the solution. Each step appeared much more rapidly than he could work it out by hand on the actual slate. As a result, he could give the solution almost as quickly as the whole problem was stated.

His teachers, at first, had some doubts about his honesty, thinking he had worked out some clever deceit for getting the right answers. In due time their skepticism was dispelled and they accepted him as a student who was unusually apt at mental arithmetic. He would not reveal this power to anyone and would discuss it only with his mother, who in the past had encouraged him in his efforts to banish it. Now that the power had demonstrated some definite usefulness, though, he was not so anxious to be completely rid of it, but desired to bring it under his complete control.

Work that Tesla did outside school hours interested him much more than his school work. He was a rapid reader and had a memory that was retentive to the point, almost, of infallibility. He found it easy to acquire foreign languages. In addition to his native Serbo-Croat language he became proficient in the use of German, French and Italian. This opened to him great stores of knowledge to which other students did not have access, yet this knowledge, apparently, was of little use to him in his school work. He was interested in things mechanical but the school provided no manual training course. Nevertheless, he became proficient in the working of wood and metals with tools and methods of his own contriving.

In the classroom of one of the upper grades of the Real Gymnasium models of water wheels were on exhibition. They were not working models but nevertheless they aroused Tesla's enthusiasm. They recalled to him the crude wheel he had constructed in the hills of Smiljan. He had seen pictures of the magnificent Niagara Falls. Coupling the power possibilities presented by the majestic waterfalls and the intriguing possibilities he saw in the models of the water wheels, he aroused in himself a passion to accomplish a grand achievement. Waxing eloquent on the subject, he told his father, "Some day I am going to America and harness Niagara Falls to produce power." Thirty years later he was to see this prediction fulfilled.

There were many books in his father's library. The knowledge in those books interested him more than that which he received in school and he wished to spend his evenings reading them. As in other matters, he carried this to an extreme, so his father forbade him to read them, fearing that he would ruin his eyes in the poor light of tallow candles then used for illumination. Nikola sought to circumvent this ruling by taking candles to his room and reading after he was sent to bed, but his violation of orders was soon discovered and the family candle supply was hidden. Next he fashioned a candle mould out of a piece of tin and made his own candles. Then, by plugging the keyhole and the chinks around the door, he was able to spend the night hours reading volumes purloined from his father's bookshelves. Frequently, he said, he would read through the entire night and feel none the worse for the loss of sleep. Eventual discovery, however, brought paternal discipline of a vigorous nature. He was about eleven years old at this time.

Like other boys of his age he played with bows and arrows. He made bigger bows, and better, straighter shooting arrows, and his marksmanship was excellent. He was not willing to stop at that point. He started building arbalists. These could be described as bow-and-arrow guns. The bow is mounted on a frame and the string pulled back and caught on a peg from which it is released by a trigger. The arrow is laid on the midpoint of the bow, its end against the taut string. The bow lies horizontal on the frame whereas in ordinary manual shooting the bow is held in vertical position. For this reason the device is sometimes called the crossbow. In setting an arbalist the beam is placed against the abdomen and the string pulled back with all possible force. Tesla did this so often, he said, that his skin at the point of pressure became calloused until it was more like a crocodile's hide. When shot into the air the arrows from his arbalist were never recovered, for they went far out of sight. At close range they would pass through a pine board an inch thick.

Tesla got a thrill out of archery not experienced by other boys. He was, in imagination, riding those arrows which he shot out of sight into the blue vault of the heavens. That sense of exhilaration he experienced when breathing deeply gave him such a feeling of lightness he convinced himself that in this state it would be relatively easy for him to fly through the air if he only could devise some mechanical aid that would launch him and enable him to overcome what he thought was only a slight remaining weight in his body. His earlier disastrous jump from the barn roof had not disillusioned him. His conclusions were in keeping with his sensations; but a twelve-year-old lad exploring this difficult field alone cannot be condemned too severely for not discovering that our senses sometimes deceive us, or rather that we sometimes deceive ourselves in interpreting what our senses tell us.

In breathing deeply he was overventilating his lungs, taking out some of the residual carbon dioxide which is chemical "ashes," and largely inert, and replacing it with air containing a mixture of equally inert nitrogen and very active oxygen. The latter being present in more than normal proportions immediately began to upset chemical balances throughout the body. The reaction on the brain produces a result which does not differ greatly from alcohol intoxication. A number of cults use this procedure to induce "mystical" or "occult" experiences. How was a twelve-year-old boy to know all these things? He could see that birds did an excellent job in flying. He was convinced that some day man would fly, and he wanted to produce the machine that would get him off the ground and into the air.

The big idea came to him when he learned about the vacuum--a space within a container from which all air had been exhausted. He learned that every object exposed to the air was under a pressure of about fourteen pounds per square inch, while in a vacuum objects were free of such pressure. He figured that a pressure of fourteen pounds should turn a cylinder at high speed and he could arrange to get advantage of such pressure by surrounding one half of a cylinder with a vacuum and having the remaining half of its surface exposed to air pressure. He carefully built a box of wood. At one end was an opening into which a cylinder was fitted with a very high order of accuracy, so that the box would be airtight; and on one side of the cylinder the edge of the box made a right-angle contact. On the cylinder's other side the box made a tangent, or flat, contact. This arrangement was made because he wanted the air pressure to be exerted at a tangent to the surface of the cylinder--a situation that he knew would be required in order to produce rotation. If he could get that cylinder to rotate, all he would have to do in order to fly would be to attach a propeller to a shaft from the cylinder, strap the box to his body and obtain continuous power from his vacuum box that would lift him through the air. His theory of course was fallacious, but he had no means of knowing that at the time.

The workmanship on this box was undoubtedly of a very high order, considering it was made by a self-instructed twelve-year-old mechanic. When he connected his vacuum pump, an ordinary air pump with its valves reversed, he found the box was airtight, so he pulled out all the air, watching the cylinder intently while doing so. Nothing happened for many strokes of the pump except that it made his back lame to pull the pump handle upward while he created the most "powerful" possible vacuum. He rested for a moment. He was breathing deeply from exertion, overventilating his lungs, and getting that joyous, dizzy, light-as-air feeling which was a highly satisfactory mental environment for his experiment.

Suddenly the cylinder started to turn--slowly! His experiment was a success! His vacuum-power box was working! He would fly!

Tesla was delirious with joy. He went into a state of ecstasy. There was no one with whom he could share this joy, as he had taken no one into his confidence. It was his secret and he was forced to endure its joys alone. The cylinder continued to turn slowly. It was no hallucination. It was real. It did not speed up, however, and this was disappointing. He had visualized it turning at a tremendous speed but it was actually turning extremely slowly. His idea, at least, he figured, was correct. With a little better workmanship, perhaps he could make the cylinder turn faster. He stood spellbound watching it turn at a snail's pace for less than half a minute--and then the cylinder stopped. That broke the spell and ended for the time his mental air flights.

He hunted for the trouble and quickly located what he was sure was the cause of the difficulty. Since the vacuum, he theorized, is the source of power, then, if the power stops, it must be because the vacuum is gone. His pump, he felt sure, must be leaking air. He pulled up the handle. It came up easily and that meant very definitely he had lost the vacuum in the box. He again pumped out the air--and again when he reached a high vacuum the cylinder started to turn slowly and continued to do so for a fraction of a minute. When it stopped he again pumped a vacuum and again the cylinder turned. This time he continued to operate the pump and the cylinder continued to turn. He could keep it turning as long as he desired by continuing to pump the vacuum.

There was nothing wrong with his theory, as far as he could see. He went over the pump very carefully, making improvements which would give him a high vacuum, and studied the valve to make that a better guard of the vacuum in the box. He worked on the project for weeks but despite his best efforts he could get no better results than the slow movement of the cylinder.

Finally the truth came to him in a flash--he was losing the vacuum in the box because the air was leaking in around the cylinder on that side where the flat board was tangent to the surface of the cylinder. As the air flowed into the box it pulled the cylinder around with it very slowly. When the air stopped flowing into the box the cylinder stopped turning. He knew now his theory was wrong. He had supposed that even with the vacuum being maintained, and no air leaking in, the air pressure would be exerted at a tangent to the surface of the cylinder and the pressure would produce motion in the same way as pushing on the rim of a wheel will cause it to turn. He discovered later, however, that the air pressure is exerted at right angles to the surface of the cylinder at all points, like the direction of the spokes of a wheel, and therefore it could not be used to produce rotation in the way he planned.

This experiment, nevertheless, was not a total loss, even though it greatly disheartened him. The knowledge that the air leaking into a vacuum had actually produced even a small amount of rotation in a cylinder remained with him and led directly, many years later, to his invention of the "Tesla turbine," the steam engine that broke all records for horsepower developed per pound of weight--what he called "a power house in a hat."

Nature seemed to be constantly engaged in staging spectacular demonstrations for young Tesla, revealing to him samples of the secret of her mighty forces.

Tesla was roaming in the mountains with some chums one winter day after a storm in which the snow fell moist and sticky. A small snowball rolled on the ground quickly gathered more snow to itself and soon became a big one that was not too easy to move. Tiring of making snowmen and snow houses on level stretches of ground, the boys took to throwing snowballs down the sloping ground of the mountain. Most of them were duds--that is, they got stalled in the soft snow before they accumulated additional volume. A few rolled a distance, grew larger and then bogged down and stopped. One, however, found just the right conditions; it rolled until it was a large ball and then spread out, rolling up the snow at the sides as if it were rolling up a giant carpet, and then suddenly it turned into an avalanche. Soon an irresistible mass of snow was moving down the steep slope. It stripped the mountainside clean of snow, trees, soil and everything else it could carry before it and with it. The great mass landed in the valley below with a thud that shook the mountain. The boys were frightened because there was snow above them on the mountain that might have been shaken into a downward slide, carrying them along buried in it.

This event made a profound impression on Tesla and it dominated a great deal of his thinking in later life. He had witnessed a snowball weighing a few ounces starting an irresistible, devastating movement of thousands of tons of inert matter. It convinced him that there are tremendous forces locked up in Nature that can be released in gigantic amounts, for useful as well as destructive purposes, by the employment of small trigger forces. He was always on the lookout for such triggers in his later experiments.

Tesla even as a boy was an original thinker and he never hesitated to think thoughts on a grand scale, always carrying everything to its largest ultimate dimension as a means of exploring the cosmos. This is demonstrated by another event that took place the following summer. He was wandering alone in the mountains when storm clouds started to fill the sky. There was a flash of lightning and almost immediately a deluge of rain descended on him.

There was implanted in his thirteen-year-old mind on that occasion a thought which he carried with him practically all his life. He saw the lightning flash and then saw the rain come down in torrents, so he reasoned that the lightning flash produced the downpour. The idea become firmly fixed in his mind that electricity controlled the rain, and that if one could produce lightning at will, the weather would be brought under control. Then there would be no dry periods in which crops would be ruined; deserts could be turned into vineyards, the food supply of the world would be greatly increased, and there would be no lack of food anywhere on the globe. Why could he not produce lightning?

The observation and the conclusions drawn from it by young Tesla were worthy of a more mature mind, and it would require a genius among the adults to have evolved the project of controlling the world's weather through such means. There was, however, a flaw in his observation. He saw the lightning come first and the rain afterward. Further investigation would have revealed to him that the order of events was reversed higher in the air. It was the rain that came first and the lightning afterward up in the cloud. The lightning, however, arrived first because it made the trip from the cloud in less than 1/100,000 of a second, while the raindrops required several seconds to fall to the ground.

At this time there was planted in Tesla's mind the seed of a project which matured more than thirty years later when, in the mountains of Colorado, he actually produced bolts of lightning, and planned later to use them to bring rain. He never succeeded in convincing the U.S. Patent Office of the practicability of the rain-making plan.

Tesla, as a boy, knew no limits to the universe of his thinking; and as a result he built an intellectual realm sufficiently large to provide ample space in which his more mature mind could operate without encountering retarding barriers.

Tesla finished his course at the Real Gymnasium in Gospic in 1870,

at the age of fourteen. He had distinguished himself as a scholar. In one grade, however, his mathematics professor gave him less than a passing mark for his year's work. Tesla felt an injustice had been done him, so he went to the director of the school and demanded that he be given the strictest kind of examination in the subject. This was done in the presence of the director and the professor, and Tesla passed it with an almost perfect mark.

His fine work at school and the recognition by the towns-people that he possessed a broader scope of knowledge than any other youth in town led the trustees of the public library to ask him to classify the books in their possession and make a catalogue. He had already read most of the books in his father's extensive library, so he was pleased to have close access to a still larger collection and undertook the task with considerable enthusiasm. He had scarcely begun work on this project when it was interrupted by a long intermittent illness. When he felt too depressed to go to the library he had quantities of the books brought to his home, and these he read while confined to his bed. His illness reached a critical stage and physicians gave up hope of saving his life.

Tesla's father knew that he was a delicate child and, having lost his other son, tried to throw every possible safeguard around this one. He was greatly pleased over his son's brilliant accomplishments in almost every activity in which he engaged, but he recognized as a danger to Nikola's health the great intensity with which he tackled projects. Nikola's trend toward engineering was to him a dangerous development, as he thought work in that field would make too heavy demands upon him, not only because of the nature of the work but in the extended years of study in which he would have to engage. If, however, the boy entered the ministry, it would not be necessary for him to extend his studies beyond the Real Gymnasium which he had just completed. For this reason his father favored a career for him in the Church.

Illness threw everything into a somber aspect. When the critical stage of his illness was reached and his strength was at its lowest ebb, Nikola manifested no inclination to help himself get better by developing an enthusiasm for anything. It was in this stage of his illness that he glanced listlessly at one of the library books. It was a volume by Mark Twain. The book held his interest and then aroused his enthusiasm for life, enabling him to pass a crisis, and his health gradually returned to normal. Tesla credited the Mark Twain book with saving his life, and when, years later, he met Twain, they became very close friends.

At the age of fifteen Tesla, in 1870, continued his studies at the Higher Real Gymnasium, corresponding to our college, at Karlovac (Carlstadt) in Croatia. His attendance at this school was made possible by an invitation from a cousin of his father's, married to a Col. Brankovic, whose home was in Karlovac, to come and live with her and her husband, a retired Army officer, while attending school. His life there was none too happy. Scarcely had he arrived when he contracted malaria from the mosquitoes in the Karlovac lowlands, and he was never free from the malady for years afterward.

Tesla relates that he was hungry all during the three years he spent at Karlovac. There was plenty of deliciously prepared food in the home, but his aunt held the theory that because his health seemed none too rugged he should not eat heavy meals. Her husband, a gruff and rugged individual, when carving a second helping for himself, would sometimes try to slip a healthy slice of meat onto Tesla's plate; but the Colonel was always overruled by his wife, who would take back the slice and carve one to the thinness of a sheet of paper, warning her husband, "Niko is delicate and we must be very careful not to overload his stomach."

His studies at Karlovac interested him, however, and he completed the four-year course in three years, tackling the school work with a dangerous enthusiasm, partly as an escape mechanism to divert his attention from the none too pleasing conditions where he was living. The lasting favorable impression which Tesla carried away from Karlovac concerned his professor of physics, a clever and original experimenter, who amazed him with the feats he performed with laboratory apparatus. He could not get enough of this course. He wanted to devote his whole time henceforth to electrical experimenting. He knew he would not be satisfied in any other field. His mind was made up; he had selected his career.

His father wrote to him shortly before his graduation advising him not to return home when school was closed but to go on a long hunting trip. Tesla, however, was anxious to get home--to surprise his parents with the good news that he had completed his work at the Higher Real Gymnasium a year ahead of schedule, and to announce his decision to make the study of electricity his life work. Greatly worried, his parents, who at that moment were making strenuous efforts to protect his health, were doubly alarmed. first, there was his violation of the instruction sent him not to return to Gospic. The reason for this advice they had not disclosed--an epidemic of cholera was raging. And second, there was his decision to enter on a career which they feared would make dangerous demands on his delicate health. On returning home, he found his plan definitely opposed. This made him very unhappy. In addition, he would shortly have to face a situation which was even more repugnant than entering upon a career in the Church, and that was the compulsory three-years' service in the Army. Those two powerful factors were operating against him and seeking to thwart him in his burning desire to start immediately unraveling the mystery and harnessing the great power of electricity.

Nothing, he thought, could exceed the difficulty of the predicament in which he found himself. In this, however, he was mistaken, for he was soon to face a much more serious problem. On the very day after his arrival home, while these issues were still red hot, he became ill with cholera. He had come home malnourished because of the inadequate amount of food to which he had been limited and the strain of his intense application to his studies. Besides, he was still suffering from malaria. Then came the cholera. Now all other problems became secondary to the immediate one of maintaining life itself against the deadly scourge. His physical condition made the doctors despair of saving him. Nevertheless, he survived the crisis, but it left him in a thoroughly weakened and run-down condition. For nine months he lay in bed almost a physical wreck. He had frequent sinking spells and from each successive one it seemed harder to rally him.

Life held no incentive for him. If he survived he would be forced to enter the Army and, if nothing happened to prevent him from finishing that term of something worse than slavery, he would be forced to study for the ministry. He did not care whether he survived or not. Left to his own decision, he would not have rallied from earlier sinking spells; but the decision was not left to him. Some force stronger than his own consciousness carried him through, but it had to succeed in spite of him and not because of any assistance he was giving. The sinking spells came on with startling regularity, each one with increasing depth. It seemed a miracle that he had come out of the last one, and now with less reserve strength he was sinking into another and edging rapidly into unconsciousness. His father entered his room and tried desperately to rouse him and stir him to a more cheerful and hopeful attitude in which he could help himself and do more than the doctors could do for him, but without results.

"I could--get well--if you--would let me--study electrical--engineering," said the prostrate young man in a hardly audible whisper. He had scarcely enough energy left for even this effort; and having made the speech, he seemed to be dropping over the edge of nothingness. His father, bending intently over him and fearing the end had come, seized him.

"Nikola," he commanded, "you cannot go. You must stay. You will be an engineer. Do you hear me? You will go to the best engineering school in the world and you will be a great engineer. Nikola, you must come back, you must come back and become a great engineer."

The eyes of the prostrate figure opened slowly. Now there was a light shining in the eyes where before they presented a death-like glaze. The face moved a little, very little, but the slight change this movement made seemed to be in the direction of a smile. It was a smile, a weak one, and he was able to keep his eyes open although it was very apparently a struggle for him to do so.

"Thank God" said his father. "You heard me, Nikola. You will go to an engineering school and become a great engineer. Do you understand me?"

There was not enough energy for voice but the smile became a little more definite.

Another crisis in which he had escaped death by the narrowest margin had been passed. His rise out of this situation seemed almost miraculous. It seemed to him, Tesla later related, that from that instant he felt as if he were drawing vital energy from his loved ones who surrounded him; and this he used to rally himself out of the shadow.

He was again able to whisper. "I will get well," he said weakly. He breathed deeply, as deep as his frail tired frame would permit, of the oxygen which he had found so stimulating in the past. It was the first time he had done so in the nine months since he became ill. With each breath he felt reinvigorated. He seemed to get stronger by the minute.

In a very short time he was taking nourishment and within a week he was able to sit up. In a few days more he was on his feet. Life now would be glorious. He would be an electrical engineer. Everything he dreamed of would come true. As the days passed he recovered his strength at a remarkably rapid rate and his hearty appetite returned. It was now early summer. He would prepare himself to enter the fall term at an engineering school.

But there was something he had forgotten, everyone in the family had forgotten, in the stress of his months of illness. It was now brought sharply to his and their attention. An Army summons--he must face three years' military servitude! Was his remarkable recovery to be ruined by this catastrophe, which seemed all the worse now that his chosen career seemed otherwise nearer? Failure to respond to a military summons meant jail--and after that the service in addition. How would he solve this problem?

There is no record of what took place. This spot in his career Tesla glossed over with the statement that his father considered it advisable for him to go off on a year's hunting expedition to recover his health. At any rate, Nikola disappeared. He left with a hunting outfit and some books and paper. Where he spent the year, no one knows--probably at some hideaway in the mountains. In the meantime, he was a fugitive from Army service.

For any ordinary individual this situation would be a most serious one. For Tesla it had all the gravity associated with ordinary cases, plus the complication that his family on his father's side was a traditional military family whose members had won high rank and honors in Army activities, and many of whom were now in the service of Austria-Hungary. For a member of that family to become equivalent to a "draft dodger" and a "conscientious objector," both, was a serious blow to its prestige, and could provoke a scandal if word of the situation got into circulation. Tesla's father used this circumstance and the fact of NikoIa's delicate health as talking points to induce his relatives in Army positions to use their influence to enable his son to escape conscription and avoid punishment for failing to respond to the Army call. In this he was successful, apparently, but required considerable time in which to make the arrangements.

Hiding in the mountains and with a year's time to kill, on this enforced vacation Tesla was able to indulge in working out totally fantastic plans for some gigantic projects. One of the plans was for the construction and operation of an under-ocean tube, connecting Europe and the United States, by which mail could be transported in spherical containers moved through the tube by water pressure. He discovered early in his calculations that the friction of the water on the walls of the tube would require such a tremendous amount of power to overcome it that it made the project totally impracticable. Since, however, he was working on the project entirely for his own amusement, he eliminated friction from the calculations and was then able to design a very interesting system of high-speed intercontinental mail delivery. The factor which made this interesting project impracticable--the drag of the water on the sides of the tube--Tesla was later to utilize when he invented his novel steam turbine.

The other project with which he amused himself was drawn upon an even larger scale and required a still higher order of imagination. He conceived the project of building a ring around the earth at the Equator, somewhat resembling the rings around the planet Saturn. The earth ring, however, was to be a solid structure whereas Saturn's rings are made up of dust particles.

Tesla loved to work with mathematics, and this project gave him an excellent opportunity to use all of the mathematical techniques available to him. The ring which Tesla planned was to be a rigid structure constructed on a gigantic system of scaffolding extending completely around the earth. Once the ring was complete, the scaffolding was to be removed and the ring would stay suspended in space and rotating at the same speed as the earth.

Some use might be found for the project, Tesla said, if someone could find a means of providing reactionary forces that could make the ring stand still with respect to the earth while the latter whirled underneath it at a speed of 1,000 miles per hour. This would provide a high-speed "moving" platform system of transportation which would make it possible for a person to travel around the earth in a single day.

In this project, he admitted, he encountered the same problem as did Archimedes, who said "Give me a fulcrum and a lever long enough and I will move the earth." "The fulcrum in space on which to rest the lever was no more attainable than was the reactionary force needed to halt the spinning of the hypothetical ring around the earth," said Tesla. There were a number of other factors which he found necessary to ignore in this project, but ignore them he did so that they would not interfere with his mathematical practice and his cosmical engineering plans.

With his health regained, and the danger of punishment by the Army removed, Tesla returned to his home in Gospic to remain a short time before going to Grätz, where he was to study electrical engineering as his father had promised he could do. This marked the turning point in his life. Finished with boyhood dreams and play, he was now ready to settle down to his serious life work. He had played at being a god, not hesitating to plan refashioning the earth as a planet. His life work was to produce accomplishments hardly less fantastic than his boyhood dreams.