OSAIN, the son of Zeyneb, the delightful Oriental sweetmeats, was quite comfortable as he sat in the squalid, shaded alley outside his mother's door. Oh, yes; very.

Dissatisfied thoughts wandered through his brain, but he had no inkling of the events which the fates were preparing for his near future; or possibly he would not have been so peaceful of mind. Idly he toyed with the nuts whose kernels he was supposed to be removing.

It seemed to Hosain that the making of sweets was a never-ending operation. Barely would he have finished one job before he was given something else to do to prepare for another batch of nougat. Or he was made to string fat nut-kernels on cords and dip them repeatedly into thick boiling syrup until they were heavily coated with crystal-like confection. A hot job, that, truly!

Unfortunately for the quiet of the surroundings, Zeyneb, in one of her countless passages from boiling syrup to work-table, happened to notice that the boy was not working. What mattered it to her that the heat had made him a trifle less active than usual? Nothing at all. All she saw was that he had ceased work to enjoy that truly Oriental pastime drowsy contemplation of nothing at all. Worse, she saw his hand raised to insert a nice fat almond between his lips. It was too much! She uttered a shriek of wrath and darted toward the door as rapidly as her mountainous size permitted.

Thou serpent!" she cried. "Thou dog from the devil's own home! Idling thy time away while I (she shook a menacing ladle from which syrup dripped), I, thy loving mother, toil like the damned to provide thee with a crust!"

She caught up

By HAL CORRELL

a piece of broken crockery from a Hosain without ceasing her tirade. "I wait for the almonds, and thou idlest thy time away and eateth them! Haste thee, lest I give thee a taste of the ladle!"

Obediently the boy resumed his duties, although he was not much impressed by his mother's threats. They always were worse than their fulfilment. Truly, he reflected, his mother had cause to be tired and short of temper, for her lot had been hard since his father had disappeared several years ago in one of the numerous skirmishes with the Greeks.

Fortunately the city was overrun with foreigners who bought liberally of her wares and paid well for them. But even so, the growing children daily required the expenditure of more and more money, and she had to work harder and harder. Yes, it was, indeed, a blessing that Allah had

caused so many foreigners to be there them with insatiable appetites for luxuries. Never, said Zeyneb, had she imagined that human beings could devour so much sweet stuff as these foreigners from that place called "Amurica."

Again Zeyneb appeared at the door, pleased to notice that her words had borne fruit and that the boy was nearly finished with his task.

"Thou art a good son, Hosain." The boy was surprised at the mildness of the tone. How could he know that within the last half hour she had decided that it would be necessary for her to send him out into the world to fend for himself? The younger children could sell the confections, and she would have one less mouth to feed. Perhaps the knowledge that she was to part with him made her speak kindlier than was her wont.

"Come, the nougat is ready. Ar

range thy tray."

Zeyneb was wise to permit Hosain to arrange his own tray. His constant contact with the foreigners as he roved the streets, and his glimpses of their wonderful shop-windows had taught him the value of neatly arranged goods; therefore, the nougat was piled in the center while around the heap he placed tiny wicker baskets of plain figs, stuffed figs, candied figs; dates, stuffed and plain; and nuts coated thickly with candy. Fresh leaves from the vine were placed over the whole to keep off the dust and flies. Hosain did not mind the flies, but his patrons did.

His mother watched him in silence for a few

Hosain looked up in surprise, his eyes asking for an explanation. "Thou knowest, son, that I love thee?" He nodded. "And that I have tried to make a home for thee? No more can I do it, Hosain. It is time that thou shouldst go out into the world; and to-morrow I shall send thee to thine uncle, Ibrahim. Thou shalt become a murid in the zawiya of the Sheik Suliman, the murshid."

The boy's heart fell. Become a seeker after wisdom in the school of Suliman, the teacher? Become a novice in the Order of the Howling Dervishes?

"Oh, no, Mother! Cannot I do something else?"

Zeyneb shrugged with resignation. "What else is there for one in your circumstances, Hosain? Allah il Allah, and it shall be as He wills. Again I say, what else is there for you?"

"I know not, Mother. Let me think it over. If I think of something else, something in which I can earn money for you and the little ones, may I do it? I do not want to enter the school of the dervishes."

"Yes, my son. If there is anything else. But go, now. To-day you may go to that place of devils

his mother gave that permission; for heretofore she had sternly forbidden him to enter the gate. How often he had longed to see what went on behind the old palace walls!

From time to time he saw enter there small groups of boys of his age from the American and English colonies, boys in uniforms that filled his heart with envy. Some one told him that they were "Scow-oots."

"Yes, go now, my son. Take heed to thyself in that place of devils, for it is a nest of Christians. Pray Allah that thou mayest return to me unscathed."

Hosain lingered not for further instructions, but with his basket skilfully balanced on his head, sped down the ill-smelling street. Around the mosque, through the bazaars of the rug-makers and the bronzeworkers; under the tall dome of a cathedral he hurried until he stood before the gateway marked with four mystic letters: Y. M. C. A.

Sturdy young men some of them mere boys, indeed, in the uniforms of

"Amuricans," murmured Hosain, nodding approval. That was how a man should look, he agreed.

In the shadow beneath the arch of the gateway Hosain stopped. Was it safe to go farther? These foreigners often did most unheard of thingsright out in the open street. What might they not do inside the walls?

Slowly he entered the place that once had been the outer court of a pasha-perhaps a pasha of only one horse-tail, a governor of a province, for it was a noble building. A pasha of two or three horse-tails could not have afforded a place like this, thought the boy.

The spacious court was now roofed with canvas to temper the heat of the sun. Curiously Hosain looked around at the groups of boys and young men, some reading, some playing games. He approached a table where several young fellows were foolishly knocking little circles of wood around on a rimmed board. The young Turk could see nothing to the game, but the others seemed to be enjoying it.

One of the fellows-always thereafter called "He of the Goldenhead" by Hosain-looked up as Hosain paused beside him. He glanced at the basket.

Hosain had picked up a working vocabulary of English, and he named his price and turned to another table.

"Nugget, effendi?" Hosain was not slow to pick up a new word. "Feegs? Date-ess?"

His mother had spoken truly about these foreigners, for their desire for sweets was boundless. They swooped down upon the tray in rivalry to see which of them could secure the most of the toothsome wares. Nor did they grudge the coins which showered down in payment. There was no Oriental haggling with them.

Some one called an announcement, and the groups moved slowly toward a door in the rear, Hosain trailing along, unnoticed. The room into which they went was dimly lighted, and a moment later it became totally dark for an instant; then Hosain

gasped, for at the other end appeared that displayed his even white teeth a disk of brightness that almost Hosain showed the empty tray. His immediately gave way to a section mother would be pleased when she of a street bounded by huge most saw it. huge buildings. In the streets jammed automobiles moved. Streetcars moved along. Men, women, children, horses, automobiles, carsbut not a sound from them.

Moving pictures! Had not a liar told Hosain that there were such things? Hosain had known it to be a lie-but-here they were! The scene changed a number of times, until one came that held the young merchant enthralled. A vast valley in which stood scores of glistening white tents. Before the tents, in great lines, handsome boys were drilling-Scow-oots! They broke ranks and raced for a swimming-pool. They did all kinds of stunts that held Hosain breathless.

The pictures flickered out and the lights came on. Again Hosain followed the others from the room. Most of them passed through a door at the rear of the court, from beyond which could be heard shouts of laughter.

"Hot dog!" exclaimed the American in surprise. "All gone already? Good business, eh? Well, come again to-morrow, and bring lots of it. Get me? To-morrow."

Hosain thought he understood, so he nodded. But what did "hot dogs" mean? Perhaps it was an invocation of some kind. If so, he would use it. It might bring luck.

"Say, kid," continued Goldenhead, "you look as hot as I feel. How about a shower?"

Hosain did not know what a shower was; but surely this good-looking, good-natured chap could mean no harm. Hosain nodded.

"Yes? All right, come along."

The American led the way while, with still a trifle of trepidation, Hosain followed to the other room. There the latter paused in amazement. Never had a young Turk seen a room like this. In the center of the court, where once no doubt there had been a "Hi, youngster! Got any more tinkling fountain, a great section of nugget?" the mosaic pavement had been reIt was Goldenhead. moved to make a place for a swim"No, effendi." With a happy grin ming-pool. At the far distant end

of the court perforated pipes that continually shot streams of water had been suspended from the balcony above. In one corner several fellows were playing with a great ball which they tried to throw into a cord basket fastened to a frame above their heads. The ball shot out of their hands and into the pool, where the swimmers grabbed it and kept it despite the remonstrances of the original possessors. Hosain, following the example set by the others, quickly jerked off his single garment and was about to plunge in the inviting water.

"Not so fast there, kiddo!" Goldenhead grabbed him and thrust him under the shooting streams of water and tossed him a cake of soap. A quick glance told Hosain what to do, and he proceeded to enjoy his first bath with masses of soap-suds lathered over his body. Ah, he decided, these foreigners did know some worth-while things!

Suddenly Goldenhead caught Hosain's wrists, crossed, swung the slender form behind him, astride his back; and all in the same movement, leaped to the edge of the pool and gave a mighty dive.

Instinctively Hosain clasped his (Continued on page 156)

LAST

COSMIC RAYS AST month I referred to cosmic rays. Now I wish to tell you something more about them. The term "cosmic" pertains to the universe as a whole, to the infinite depths of space, stretching away beyond our little planet and even beyond our solar system without end. Did you ever stop to consider whether there might be bounds to space? Suppose you could take the wings of the morning and with the velocity of light travel onward forever and a day. Could you come to a place where there is no further space? If so, what would you find, a high stone wall? And what would be on the other side of it but space? No, despite Einstein, we cannot conceive of the beginning or the end of space. Cosmic rays are a highly penetrating form of infinitesimally short waves in the ether coming from the depths of this vast universe, as plentiful from one quarter of the heavens as from another. They were discovered by Dr. Werner Kolhoerster, a German scientist, early in the present century. They have been studied most carefully by Dr. Robert A. Millikan, winner of the Nobel prize in physics in 1923, and one of the foremost physicists, not only of America but of the world. Although the world has been bathed in these cosmic rays from the beginning of time, no one suspected their existence, so to speak, until the other day.

Millikan carried his detecting instrument, an exceedingly sensitive self-recording electroscope, to Lake Muir, near the summit of Mount Whitney, 11,800 feet above sea-level. Then he sunk this instrument in the water of the lake, and it continued to record the presence of an electric vibration in the ether to a depth of forty-three feet. But before these waves struck the water they had already penetrated the earth's atmosphere, which is equivalent to an additional depth of twenty-three feet. In other words, these mysterious rays were able to pass straight through sixty-eight feet of water, and still have sufficient energy left to affect an electric measuring device. And sixty-eight feet of water are equivalent to six feet of lead. The most powerful X-rays which we can gener

By FLOYD L. DARROW

rays nearly one hundred and fifty times as powerful, and Millikan has just recently discovered that they will make their way through eleven feet of lead. What is this form of energy and how does it originate? Let us see what light investigations have thrown upon the subject.

Radium constantly gives forth a radiation known as gamma rays, a form of natural X-rays, but exceedingly more energetic and penetrating than laboratory X-rays. Like X-rays, gamma waves are due to waves in the ether, but of almost inconceivably short lengths. The cosmic rays, in turn, are vastly more penetrating than are gamma rays. Consequently, they are thought to be due to still shorter waves in the ether, generated in every quarter of the celestial spaces and traveling in all directions. But what is their cause? That was the baffling question. To give the present views of scientists, I must tell another story.

Many of you know that scientists now have a wealth of the most reliable evidence to show that an atom is a miniature solar system, consisting of

planetary electrons of negative electricity revolving in orbits about a positive nucleus. Now this nucleus consists largely of protons, a proton being a minute point of positive electricity equal in quantity to the negative electricity of an electron. Furthermore, scientists believe that these final units of matter, the electrons and protons, consist of nothing but electricity. That is, there is no infinitesimally small core of hard matter charged with electricity. The electric charge is the whole thing. Ordinarily, the exceedingly swift motions of the electrons in their orbits keep them from uniting with the protons, with the consequent destruction of both. But suppose an electron and a proton could meet in a head-on collision. The electric charge of one would exactly neutralize the charge of the other, and both would disapppear. In doing so, this change would liberate a highly intense form of energy. Now this is precisely what scientists believe is constantly happening in the spiral nebulae and in the cosmic crucibles of the stars. As Professor Eddington, of the University of Cambridge, says, "We are to suppose that a proton and electron run together, their charges cancel, and nothing is left but a splash in the ether, which spreads out as an electromagnetic wave carrying off the energy." These electromagnetic waves are the cosmic rays.

Now I fancy that some of you are becoming alarmed for fear that the law of the conservation of matter, about which you study in high-school physics and chemistry, is about to be overthrown. Well, this law has come to be seriously modified from the older view. Einstein has shown that matter may be transformed into energy, and the production of the cosmic rays is more than likely an example. Furthermore, he has worked out the equation governing this transformation. He gives it as follows: E = Cm. E stands for the energy liberated, C for the velocity of light, and m for the quantity of matter being transformed.

If I were to talk of sixty tons of sunlight, you would immediately say I am dreaming, and liken me to the peasants who are said to have gone out to gather sunlight in baskets for the purpose of lighting a room in which they had foolishly forgotten

As

to put windows. But I mean to do just that, and I assure you that I am perfectly wide awake. Professor Eddington told us a short time ago that one hundred and twenty billion tons of the sun's mass are converted into energy each year and radiated into space. This annihilation of matter and its transformation into energy are supposed to be brought about by the destruction of electrons and protons as described above. tronomers tell us that our earth receives of this huge total of radiant solar energy only one two-billionth. Therefore, the simplest sort of an arithmetical calculation shows you that sixty tons of energy in the form of sunlight constitutes the working capital of our little planet for a year. Without it, streams would disappear, waterfalls would cease to flow, vegetation would fail to grow, and our earth would become a cold, dead world.

The other day I figured out that 0.231 pounds of the sun's mass are converted into energy for the benefit of the earth each minute. Then I substituted this value in Einstein's equation, and found that this appar ently insignificant quantity of solar matter yields us the inconceivably vast amount of two hundred and thirty-three quadrillion (233,000,000,000,000,000) foot-pounds of energy per minute. If you wish to make this calculation, you must change the velocity of light, 186,000 miles a second, to feet, and then square this huge number in accordance with the equation. It is this which gives such a prodigious result. Next, knowing that 33,000 foot-pounds per minute make a horse-power, I calculated the power output of solar energy received by the earth. It turned out to be about six trillion seven hundred and sixty-five billions of continuous horsepower. This is equal to the energy content of ten million Niagaras. To obtain this amount of energy from the burning of coal would require an annual output nearly twenty times as great as the total quantity contained in the coal-measures of this country when the white man first put foot upon these shores. It is forty-five thousand times as much as is used in the whole world for all mechanical power purposes whatsoever. To supply the amount of energy contained in the sunlight captured annually in the production of plant foods everywhere would require the burning of 8900 times as much coal as the world now produces. The sunlight falling upon the United States in a minute, if utilized without loss, would meet our entihutes y requirements for a yeaents ne solar

protons in connection with the birth of cosmic rays. The explanation of the solar fires has been a long-standing puzzle. It seems now to have been solved. As you see, too, it is now perfectly correct to speak of a ton of sunlight or a pound of electricity.

MEASURING FOUR BILLIONTHS OF AN INCH

MR. P. P. CIOFFI, a scientist in the Bell Telephone Laboratories, has recently perfected the most delicate measuring apparatus in existence. Just think of being able to measure exactly such an exceedingly short length as a billionth of an inch! And yet that is precisely what this instrument does. The need for such a device grew out of another discovery in these same laboratories, that of a new alloy called "permalloy." This is a combination of nickel and iron which can be magnetized and demagnetized more rapidly than any other metallic substance. Through its use cable messages may be transmitted five times as rapidly as formerly. It is being used extensively in telegraph and telephone devices.

For many years it has been known that the size of a magnetic substance changes when it undergoes magnetization. For instance, pure nickel contracts when it is magnetized, while iron expands. Why, no one knows.

ventor, an instrument was needed which would measure a change of length "of the order of one tenth of the diameter of an atom." And it was the work with permalloy, which undergoes exceedingly slight changes with magnetization, which made such a device necessary. But just think of the extraordinary boldness of the man who should undertake to invent apparatus capable of measuring so infinitesimal a distance as one tenth the diameter of an atom!

It required about a month for Mr. Cioffi, to whom this task was assigned, to work out the plan of his device, but it took several months to bring it to perfection. Although this apparatus is a complicated one, its principle is not difficult to understand. The expansion or contraction of the metal being examined is made to tilt a mirror very slightly. This tilting reflects light into a photoelectric cell of great sensitiveness. As you know, even the slightest change in the intensity of light falling upon such a cell, varies the current flowing from it. Although the change in size of a metal in undergoing magnetization is infinitesimally small, it is sufficient to operate this apparatus and thus vary the current flowing from the cell. These minute changes in the electric current are measured by a very delicate galvanometer,