At first sight, it might appear that we invariably cry because we are sad, but this is by no means the case! We may cry because we are hurt, physically or mentally, or because of joy or excessive happiness, or because of any tender emotion, or when hearing beautiful music, or seeing some splendid action of bravery, or for many other reasons.

Like laughter, crying may thus be due to various causes. Some of these are purely physiological, due to sensory impressions or congestion of the circulation. Thus, smelling onions will induce a flow of tears—a defensive mechanism to protect the eyes. A foreign body, an insect or a particle of dust in the eye will induce the same result. Again tears are protective. Coughing, vomiting, strong effort, will also cause the eyes to water; and here again “crying” is brought about by physical means alone.

Weeping is usually due to some strong psychic initiation, however, such as some powerful emotion. But this must find expression through the mechanism of the body, and this consists in a stimulation of the tear glands (lachrymal glands) situated just above the eyes, whose normal duty it is to supply just enough fluid to keep the eyes moistened. Excessive stimulation of these glands will cause a flow of tiny drops of water, which run across the eyes, and into the nose; but if an excessive quantity of water be produced at once, they overflow the eye-lids and fall onto the cheeks—“crying.”

This sudden increase of the lachrymal secretion depends upon the increase in the pressure of the blood; this in turn is increased by the emotions of joy or tenderness, as is proved by the “shining” of the eyes. The appearance of tears would be the natural consequence. Tears produce relief by lessening this congestion within the head. They are a safety-valve on the part of Nature. We cry to relieve this internal congestion.

If you are worried, anxious, angry, you knit the brows into a “frown,” and the same is true if you are trying to recall some lost thought. Why should the same outward expression be the symbol of so many differing emotions? There being so many varying emotions, it seems strange, at first sight, that the frown should represent them all! Why is this? Why do we frown, on these various occasions?

A frown is due, physiologically, to the bringing together and lowering of the eye-brows and the muscles just above them. This is accomplished by the “corrugator” muscles, whose duty it is to contract the brows. Now, a man may be working along for several hours, on an abstruse problem, and never contract his brows; suddenly he does so! He has struck something in his line of thought which is particularly difficult or displeasing to him. It is the occurrence of this emotion which has induced the frown.

Anything which induces an unpleasant emotion, therefore, may induce a frown. If the food is not good, a man may frown at his wife; if the milk is too cold, a baby will frown before crying. During intense thought, the brows are only contracted when an idea, or a word, or mode of expression is lacking. This sub-conscious irritation is then expressed in a frown.

Another cause had probably strengthened the habit of frowning. That is the endeavor to see more clearly at a distance. Short sighted people often contract the eyes and the forehead in an effort to see with greater distinctness. (This action has, in fact, given rise to the term “Myopia,” from the Greek.)

Contraction of the brows also tends to shut out an excess of light, which would also be an impediment to clear seeing. Frowning, therefore, serves several good purposes, and may be brought about by several distinct causes.

You know that when you meet a stranger, or even an old friend, and you greet him, your impulse is to smile as you extend your hand. This is a smile of recognition, of good-feeling and affection. It has become instinctive with us, and we do it without ever thinking of its origin or significance. But there must be some natural reason for this habit. What is it?

Charles Darwin first pointed out that the muscles used in smiling were also the muscles used in snarling. You have often seen two dogs, who are doubtful of each other, approach gradually, pulling back their lips in a half snarl, as though uncertain of their reception by the new-comer. It indicated that the dog was ready to fight, if necessary, and was a sign of warning—to “beware.”

Now, when one smiles, it is probably an evolution of the snarl, which was originally a sign of defense. We smile on meeting strangers because our animal ancestors snarled at them—as monkeys do to-day when any stranger approaches them or attempts to handle them or pick them up. (This can be observed in the case of any pet monkey.)

However, there is doubtless more to the smile than this. We smile, it is true, even after we are assured of their friendship, and we smile when we say “goodby.” We would not naturally snarl under these circumstances! So the smile is also a physical expression of happiness—a half-laugh, of gladness, of joy. It is also an expression of amusement. The smile lifts the muscles of the face, keeping it young and fresh, and free from wrinkles, and has a beneficial effect upon it—just as worry and gloom cause the features to droop, and the corners of the mouth to “sag.” For these reasons, it is safe to say: “Smile, smile, smile!”

“The blush of maidenly modesty” has often been the theme of the poets—and the novelists! It is an indication of timidity or bashfulness. Girls and young women are particularly subject to blushing; and a pretty speech, a compliment, a personal allusion will bring a blush to the cheeks as readily as will shame or anger. Intense emotions of this character will usually bring about a blush.

Needless to say, a blush is, superficially, a sudden rush of blood to the face and neck, filling the smaller blood vessels with arterial blood—for if it were venous blood we should blush blue! This instantaneous control of the circulation by a sudden emotion is in itself of remarkable interest. It must be brought about by sudden nervous impulses, checking and accelerating the blood-supply in the face. Hack Tuke asserts that the blush of shame begins in the neck and ears, that of anger begins with the eyes, and that of love in the forehead.

Darwin attempted to account for blushing by supposing that a person who thinks that others are looking at him directs his attention to his own face; hence results a flow of blood towards that part. Such explanations are now rejected. The experiments of Mosso and others, on the circulation of the blood, seem to point to the view taken by the psychologist Wundt—who contended that the normal checks to the blood supply were temporarily suspended, as compensation for the accelerated pulsations of the heart, produced by emotion.

On this view, the emotions of shame, anger, etc., cause you to blush because the nerves which control the blood supply in your face are temporarily “inhibited”; more blood to these parts reacts in consequence.

When an ordinary individual thinks he suddenly sees a “ghost” he turns pale, his hair stands on end, and he “trembles from head to foot.” Often he breaks out into a cold perspiration, and may even faint!

All these symptoms are well known; there is only one which many persons would refuse to believe—putting it down to a subjective hallucination. That is the hair standing on end! This is actually the case, however, at such times; for, attached to each hair is a tiny muscle which shortens under the influence of this emotion, and as it shortens, it pulls the hair upright just as a beam might be pulled upright by a rope—thus causing it actually to “stand on end.”

The face turns pale, under the stress of fear, because the blood vessels under the skin are suddenly emptied of blood—due to nervous control of the so-called “vaso-motor” system. This blood is emptied into the great blood vessels in the interior of the body, which rapidly expand to receive it. A new distribution of the blood takes place, in which the surface of the body is left without it, while the interior of the body is filled instead.

This does not only happen in the case of fear, for sudden anger may also make the face blanche. Furthermore, the face alone is not bereft of blood in this manner; the whole surface of the body is affected, so that it becomes pale and anaemic, for the time being. When this sudden withdrawal of blood extends to the brain the subject becomes faint, and may even lose consciousness. Facial pallor, therefore, is just the reverse of blushing, and curiously enough, may be due to the same emotions—and succeed each other in waves.

There are two types of creature in the world—the cold-blooded and the warm blooded. Frogs, snakes, etc., are examples of the former; cats and dogs of the latter category. Lizards, snails and fish are cold blooded; lions, tigers, horses are warm blooded. Man is also a warm blooded animal.

There is this remarkable distinction between them: That, whereas cold blooded creatures take on the temperature of their environment (whatever that may be), warm blooded animals always remain at approximately the same temperature, no matter what the external heat or cold may be. Thus, if a frog is placed in a temperature of forty degrees Fahrenheit, he will soon be of that temperature also. Cold blooded creatures may even be frozen stiff, and yet revive, when thawed out. Above a certain temperature of heat, however, they all die.

In the case of warm blooded animals, however, the case is quite different. Thus, man’s temperature, in health, always remains the same—about ninety-eight degrees Fahrenheit. No matter whether he is sweltering in the tropics, or exploring the icy regions of the Polar Seas, his bodily temperature remains the same. (As soon as he dies, however, his corpse assumes the temperature of the surrounding air.)

The constant temperature of the human body, therefore, is somehow dependent upon life. Nature has provided a number of mechanisms and adjustments to keep the temperature normal. In very cold weather, the skin contracts, to prevent too large a volume of blood from reaching the surface, and becoming cooled. In hot weather, the pores of the skin open, perspiration pours forth, evaporation takes place, and this serves to cool the body.

The heat of the body is maintained by combustion, burning up the food we eat; and if too much is yielded, the body disposes of it. But just why Nature has decided upon the exact degree of bodily heat we possess is as yet an unsolved mystery. It seems, however, the one best suited for our purposes.

“I feel hungry because I need food,” or “because I want to eat,” would be the usual answer to this question. And yet a moment’s thought would show us that these are no answers at all. Why do you want to eat? Because you are hungry! We are in what is termed a “vicious circle” of reasoning at once, in which we run around like a dog chasing its own tail, and getting nowhere!

What is the real cause of hunger? In a certain sense, of course, it may be said to be a general expression of craving on the part of the body for food, in order to repair the wastes, due to exercise, etc. In one sense, hunger is a general condition—the bodily cry for solid food, just as thirst is the bodily cry for liquid of some sort. The tissues need to be fed. And this cry finds its local expression in the stomach, when it is empty.

But we must be careful to define just what we mean by hunger. There is a true hunger and a false hunger—known to physiologists as “habit hunger.” This often appears at meal times, just from habit, no matter whether the body really needs food at all, or not. This is not true hunger, or appetite: for if a glass of water be taken and the mind diverted, this craving will soon disappear—which would be impossible if true hunger were being manifested.

As soon as the stomach is really empty, slight muscular contractions begin to take place. These pass like waves or ripples across the stomach, and increase in frequency and violence the longer food is withheld. These contractions are what we feel, and know as “the pangs of hunger.” They are the local cry of the stomach for food. We feel this craving in the stomach, and also bodily craving. Together, they make up the set of symptoms known as hunger, and it is because of them that we feel “hungry.”

Perhaps the cynic might reply to this question that women’s hair does not turn grey any more—there are too many good “tinting” and “retouching” lotions on the market! But this answer is merely superficial—as all cynical answers are. Hair does continue to turn grey, and the discovery of the reason is of great scientific interest.

It is hardly necessary to say that human hair is of various colors, because of the coloring matter which it contains within its hollow shaft. This coloring matter is its “pigmentation,” and is golden, brown, black, etc., as the case may be, or combinations of various simpler colors. When the hair turns grey or white, the hair remains, but the pigmentation is somehow removed. Where has it gone, and how?

Various answers to this question have been suggested. Professor Metchnikoff suggested that the coloring matter in the hair was gradually eaten up or consumed by “phagocytes,”—which are hungry cells, that attack and devour any weakened and devitalized cells or tissues in the body. It is said that the particular cells, in this case, are situated in the central shaft of the hair, and when they once become active, they proceed to devour all the pigment within their reach! In this manner the hair gradually turns grey and finally white.

This theory may be true in a number of cases—probably the majority—but it certainly fails to account for many instances, in which hair has been turned white, or blanched, over night, as the result of worry or fear. In these cases, strong emotion has produced the change. Science cannot as yet explain how this comes about, and this sudden blanching of the hair is yet a mystery. In the majority of cases, however, the pigment in the hair is undoubtedly consumed.

“Oh,” you will say, “I laugh because I am happy or amused!”

Which may be very true, but your simple reply does not quite answer our question. You may also laugh in derision or disdain, you may laugh when at play, you may laugh at something novel, from a sense of freedom, from the mere joy of living, or even at the misfortune of another—as you so often do when looking at slap-stick comedy. So there are many kinds of laughs, all of which are due to varying causes.

There are probably two main causes for all laughter. One is physical, or rather physiological; the other is mental or emotional. When we laugh in play, or because we “feel good,” this is due to superabundance of energy. It is always the robust, hearty man who laughs, though his crabbed, anaemic brother rarely does. This energy can find a ready outlet in no other manner, so finds its expression in smiles and laughter.

Comedy situations of any sort—on the stage or screen or in real life—cause laughter because they release, in an individual this spring of reserve energy. Laughter follows. This spring of reserve is loosed when the sense of the comic, the ludicrous or the absurd is touched. And this brings us to the mental factor.

Why does anything strike us as particularly “funny”? Many things do merely because they are unusual or novel (different clothes), or because we see someone finding it difficult to perform an action we could easily perform, (lifting some light object), or because some man is abnormally stupid or foolish or ignorant. The source of laughter in all such cases is the same; we feel a sense of superiority over that individual, and laughter arises from our consciousness of our superiority. We laugh from strength, at weakness. It is ultimately a case of the “survival of the fittest.” It is biological.

If you cut your finger, or cut or break the skin on any part of your body, you begin to bleed, for the simple reason that some of the tiny blood vessels near the surface have been injured, and blood oozes from them. But, after a few moments, the bleeding tends to stop, and, if the cut is not a very severe one, it usually ceases of its own accord very shortly. A sort of protecting crust is formed, and the flow of blood is stopped by Nature’s own methods.

What has happened to cause the flow to cease? Various things, the most important of which is “coagulation,” or clotting of the blood, as soon as it is exposed to the air. It is very interesting to see just what happens here—during this process of clotting.

The cause of clot-formation has been found to be the precipitation of a solid form, the liquid plasma of the blood. This solid is in the form of very minute threads, and hence is termed fibrin. The threads traverse the mass of blood in every direction, interlacing, and thus confining in their meshes all the solid elements of the blood. They soon begin to contract, when out of the body, and form a minute mesh-work or net, carrying within it the corpuscles of the blood. These corpuscles within the fibrin form the clot.

After a time, a yellowish fluid forms on the outside of the clot; this is the serum, and is squeezed out of the solid constituents of the blood, as the latter dries like water from a squeezed sponge. Altogether, about a third as much serum is formed on the clot as the solid material of the clot itself!

Recent experiments conducted in Harvard University have shown that the adrenal glands (one of the ductless glands in the body) will hasten coagulation, and any strong emotion will do the same thing. As most injuries are received during some strong emotion, this is evidently another of Nature’s plans to hasten clotting and prevent the unnecessary loss of blood.

It is a curious fact that most of the blond races of the earth live either in the temperate or frigid zones, while the brunettes live in the hotter, tropical countries. Thus, the Swedes, Norwegians, Danes, Germans, English, etc., are generally blond or fair people; while the Spanish, French, Italians, Portuguese, Greeks, Turks, etc., are dark. The further south we go, the darker do the inhabitants become: witness the Turks, Arabs, Moors, Hindus, etc.,—ending with the Negroes in Africa and other tropical countries. (I am speaking, of course, of original, native inhabitants of these zones, and not individuals of races who have lately migrated there.)

Nations once fair and blond in coloring become brunette in time, if they continue to live in southern climes. The Greeks are a good example of this. They were, as we know, originally fair, with beautiful golden hair; yet today they are dark, with swarthy complexions and black hair. They no more resemble their ancestors than chalk resembles cheese!

Why is this?

The answer undoubtedly is that the intense heat of the tropical sun darkens these people, in succeeding generations. As a defense against the intense heat-rays, Nature begins to lay down pigmentation under the skin, as a protection from the sun. This pigmentation under the skin serves to shut off the most burning rays, and to protect the individual against excessive “scorching.” We notice an extreme example of this in the Negro, whom Nature has evidently adapted to live in a hot climate. Even white people living in the tropics soon become so tanned that they remain permanently brown. The gradual darkening of the skin and hair, therefore, is a protective mechanism on the part of Nature, showing us that brunettes are more adapted to warm climates than are blonds, who are the natural inhabitants of temperate or cold climes.

Every veteran of the World War will bear testimony to the fact that wounds inflicted in the heat of battle frequently do not hurt; pain is only experienced later on! A man may be wounded—even badly—and hardly realize it for the time being. In his anger or excitement he does not feel any pain or notice his injury. And we do not have to go to war for proof of this. We have all of us scraped a finger, and drawn blood, probably, without noticing it at the time. Only when our attention is drawn to it later do we feel qualms, and perhaps pain! One is almost reminded of “Alice Through the Looking-Glass,” when she observed the White Queen scream first, bleed next and prick her finger last!

Yet even the slightest injury will cause us pain if our attention be centered upon it at the time. A slight prick of a needle—enough to draw one drop of blood—is keenly felt, if the mind is centered upon that spot at the time. Why is it that the distraction of attention, and particularly the arousing of strong emotions at the time, will prevent or “inhibit” the sensation of pain?

The reason probably is that the nervous currents of the body, at such times, are almost entirely “motor” currents—that is, nervous currents which rush outwards from the central nervous system to the surface of the body. Pain currents are incoming currents, and if there is no room for them to get by, so to say, pain will not be experienced at the time.

It is like a railroad terminal, with an outgoing train on every track. There is no room for incoming trains. The incoming trains are the “pain” trains, which carry sensations. The outgoing trains correspond to the motor nervous currents. That is why pain is not felt at such times. As soon as the human tracks are cleared, and incoming nervous currents can get through, pain is experienced for the first time.

The answer to this question, in the estimation of many people, would be very simple: “I’m not!” They would contend that they are the same height in the morning and at night, and may even think that the question is more a joke than anything else.

And yet, if such skeptics would take the trouble to measure themselves, upon arising, and again just before going to bed at night, they would find that they are a goodly fraction of an inch taller in the morning! This may be much more noticeable in some cases than in others, of course; but the fact remains that an appreciable difference exists, and can be clearly proved in very many instances.

And why? There seems to be no reason, at first sight; and yet, if true, there must be some reason after all. What happens to make us taller in the morning?

The human body is held erect partly by the skeleton and partly by the muscles. The “backbone” (spine) is the main support which holds the body erect. But the spine is not a solid bone; if it were, we should never be enabled to bend in various directions at will. It is made up of a number of small bones called “Vertebrae,” tightly bound together by ligaments.

If these bones rested one upon another, they would tend to “grate,” and the jarring to the human brain and body would be terrible. In order to prevent this, Nature has provided a sort of soft pillow or cushion between each vertebra, and this cushion becomes, as it were, “puffed-out” at night, when the weight is taken off the spine. During the day time, the little cushions become somewhat flattened. That is why we are taller in the morning than at night. The little cushions between the vertebrae made the difference in height!

It has frequently been pointed out that “da” is among the first of the voluntary sounds produced by a baby. Why is this? The reason is probably that the sounds which are first produced are those which require the least effort; these are the guttural sounds, produced by the mouth organs, produced further back, near the throat, and the dental sounds, in the production of which the teeth (or gums) coöperate with the tongue. These nerves and muscles, controlling these portions of the anatomy, are also those connected with the primative sensorimotor activity, so that the first sounds are produced in connection with some physical motion—such as pointing. The nervous impulses which are utilized in pointing also pass over and assist in producing the first primative sounds, which as we have seen are the dental and guttural.

Why, then, does the baby say “da” instead of “ga” when it points? The answer is to be found in the considerations which we have just applied. The act of pointing sets into motion one of the extremities of the body. The nervous process, one of whose divisions goes into this extremity, can naturally reach by one of its other divisions more easily the muscles of the frontal part of the mouth, belonging to the periphery (surface) of the body, than the muscles of the throat, belonging to a different, an internal, system of muscular activity. Try yourself to accompany a pointing movement by a dental or a guttural sound. The latter seems more natural. (See Max Meyer: “The Fundamentals of Human Behavior.”)

Objects appear to us to have different colors—some of them are green, some are red, some blue, some black, etc. Yet modern science has shown us that no such thing as “color” exists in the universe at all! Nothing is colored; color does not exist upon the object; color exists in the human mind, and objects merely appear to us to be colored. We put the color onto them, so to speak. Color is a quality of an object. Why, then, do objects appear to us to have different colors!

The reason for this is that the surface of the object is so made or constituted that certain light rays of the visible spectrum are absorbed, while others are reflected. Those which are thus reflected represent the “color” of the object. If all the light rays were thus absorbed, and none reflected, the object would become “invisible” to us, but no object does this: if such a substance could be discovered, we should have the “Invisible Man” of H. G. Wells. Color does not exist on the object, therefore, but is merely a quality of the object; and different objects appear to us to have varying colors because of their varying absorption and reflecting qualities.

Similarly, no such thing as sound exists in the universe. If there were no living being on our globe, no such thing as “sound” could exist. A train of cars might fall off a high bridge with a terrific crash, but no sound would be emitted! Sound consists of air vibrations, which are in themselves soundless; these impinge upon our ears, are carried to the brain, and there transformed into sound. We then “hear” them. But these air vibrations in themselves are soundless; they might go on forever, if no human ear intercepted them, into space, and no sound would ever be heard. We feel that we might take a pair of scissors, so to speak, and snip them in the middle, before they reach the human, and thus destroy them. In such case, no sound would ever reach us. Sound, like color, is really non-existent.

Blowing soap bubbles may strike you as a very childish amusement, but from them there is much to be learned of scientific interest.

The soap bubble, as ordinarily blown, by means of a bubble pipe contains within it carbon dioxide gas, given off by the lungs. The coat of the soap bubble, composed of a mixture of soap and water, is elastic, and capable of being stretched or pulled in different directions without being broken. In order to give greater strength and elasticity to this film, a mixture of soap, water and glycerine may be employed. Common yellow soap is better than most of the fancy soaps. Castile soap will furnish an excellent soap bubble mixture.

If the soap bubble be examined, it will be found that various beautiful colors are reflected upon its surface. These colors are usually very delicate, and consist largely of pinks, blues and greens. After a few seconds, a darkish spot begins to appear at one point on the surface of the bubble. This spot becomes darker until it is almost black, and almost immediately after this the bubble bursts.

This black spot is in reality the thinnest portion of the soap bubble, and it is at this point that the film gives way first. The soap bubble skin has at this point become so thin that it will no longer reflect light-rays.

Soap bubbles have even furnished us a means of determining the size of the molecules of matter. Knowing the amount of soap and water employed, in order to produce a definite bubble, the size of the bubble, when blown, is measured, and in this way the number of molecules of soap and water in any given square centimetre of its surface can be calculated. The thickness of the film may be determined by the coloring of the bubble. Knowing the area and thickness of the soap bubble film, the number of molecules can be calculated, and in this way it has been ascertained that approximately a given number of molecules of matter are contained within that space.

This elastic coat, which we see in soap bubbles, may also be noted in other mixtures, such as alcohol and water. The strength of this skin may be seen on the side of a wine glass, in which there is some fairly strong wine, such as port. The liquid is observed to climb up the sides of the glass, and then to gather into drops and run down again, and this goes on for a long time.

This is explained as follows: The thin layer of wine on the side of the glass, being exposed to the air, loses its alcohol by evaporation more quickly than the wine in the glass. It, therefore, becomes weaker in alcohol or stronger in water than that below, and for this reason it has a stronger skin. It, therefore, pulls up more wine from below, and this goes on until there is so much that “drops” form, and run back again into the glass.

There can be no doubt that this movement is referred to in Proverbs xxiii, 31: “Look not thou upon the wine when it is red, when it giveth its color in the cup, when it moveth itself aright.”

Much more might be said on this interesting topic, but the above will at least serve to show us that we can learn facts of great interest even from the lowly soap bubble.

Are we in danger of reverting to a “second childhood” when we study the action of spinning tops? By no means, for we can learn much of great scientific value in consequence, and even throw light upon certain astronomical phenomena by an analysis of their motion.

Spinning bodies behave in a very different manner than the same bodies do at rest. For example, you can loop a chain over a wheel, which is then revolved with considerable rapidity. If, now, the chain is suddenly disengaged, it will go running off like a solid hoop, and will only collapse in an inert mass when it comes to relative rest.

If you throw a coin into the air it will come down “anyway.” But if you give it a rapid spinning motion when throwing it upwards, it will always come down with the same side upwards as when it started. (For example, if “heads” is on top when thrown, it will invariably come down “heads.”)

The same thing is true of a hat, an ink bottle, or any other object.

Another curious thing is that a spinning body, such as a top, can maintain its balance at an angle, seemingly against the pull of gravity, when the same body would at once fall to the floor when at rest.

A gyroscopic top is a good example of this: it will lean far over to the side, but it will not fall. Its spinning motion holds it in place.

If our earth were to stop its spinning motion, it would fall into the sun at once, and we should all be burned alive.

When a top is spinning, it begins to “wobble,” and these oscillations gradually increase until the top falls to the ground. If, when the top is still, you hit it a smart blow in a north-and-south direction, it will at once begin to “wobble” in an east-and-west direction. And vice versa.

All spinning bodies tend to rise up onto their longest axis. Thus, if you spin an egg rapidly, it will get up on end, and only settle back onto its side as it slows down in its speed.

Again, all spinning bodies tend to point to the Pole Star. That is why the North Pole of our earth is pointed in that direction. Every top, every wheel of every factory, and on every train and automobile in the country, when in revolution, is gently tugging to turn its axis to point toward the Pole Star. This is a remarkable and little known fact. Of course, the energy of the spinning body may not be sufficiently strong to effect this, but the effort of the spinning body is there nevertheless, and, if allowed to spin long enough and given free play, will be found ultimately to point in that direction.

An electrically driven gyroscope will prove this. In fact, there is a very interesting experiment, based upon this fact, by means of which the revolution of the earth on its axis may be seen going on before the eyes of the spectator, even if he is in a dark dungeon in the bowels of the earth!

Just one hundred years ago a flat stone was discovered in Egypt which has revealed the secrets of that ancient civilization, and has, in fact, supplied us with a key to the dim past.

For centuries the Egyptian “hieroglyphics” remained a mystery. No scholar could read them, since there was no means of beginning their interpretation. It was realized that, if these hieroglyphics could be read, they would reveal to us much concerning the civilization of ancient Egypt—its life, art and science.

While excavating in upper Egypt, M. Jean Champollion discovered a flat stone, since known as the “Rosetta Stone,” because it was discovered near the Egyptian port of Rosetta. This stone had cut in its surface an inscription in two languages—Egyptian and Greek. Further, the Egyptian language was written both in the older form of hieroglyphics and in the more modern “Demotic” characters. It seemed obvious that all three of these probably referred to the same thing, and that the Demotic and Greek lettering were but modern variations or translations of the earlier hieroglyphic script.

It therefore became the object of Egyptian students to attempt the translation of the hieroglyphics, with the other languages as partial keys.

The translation was gradually effected as follows:

It was first of all assumed (correctly) that a continuous line about certain figures indicated a royal name. This is known as a “cartouche.” It was also assumed that if the cartouche contained the name of Ptolemy, the characters in it would have the sounds of the Greek letters—since the Greek was an attempted translation.

A stone had already been found known to contain the name of Cleopatra, some of the letters of which were the same as in the name Ptolemy. For example, “l” is the second letter in Cleopatra, and the fourth in Ptolemy. “P” is the fifth letter in Cleopatra and the first in Ptolemy, etc.

Now, in examining the two stones, certain hieroglyphics were found to be the same. For example, a bird occurred in one name and apparently stood for a certain letter, where it should stand in both names according to their spelling. This bird was therefore translated as “a.” In a similar manner, a sign resembling a closed mouth was translated as “r.” A sign resembling a folded umbrella was translated as “e,” etc. In this way, letter by letter, the whole alphabet was gradually worked out, and the message deciphered.

After this, the interpretation of the Egyptian hieroglyphics became merely a matter of time and study, and today they can be read almost with facility. We now know much more of ancient history than any previous generation, so that, the further we progress from ancient times, the more we know concerning them! All this has been rendered possible by the discovery of a single piece of stone.

When we look at a map or globe of the world, we are struck by several peculiarities which require explanation. In the first place, nearly every peninsula, large and small, points toward the south—and this is even true of vast bodies, such as Africa, South America and India. Secondly, the distribution of the land and water upon the surface of the earth is peculiar—nearly all the land lying in the northern hemisphere, while the water occupies the southern half of the globe. Further, if a map be made of the land-area of the northern hemisphere, looking at a globe from the point-of-view of the North Pole, and this be laid over a similar map, drawn from the point-of-view of the South Pole, it will be found that land hardly ever falls on land, but that land in one hemisphere almost invariably coincides with water in the other. The only exception to this rule, of any importance, is that a portion of South America will be found to lie over a portion of northern China.

Why is this?

One of the newer theories of the formation of our earth explains these odd facts in a rather ingenious manner. It has been shown that a spherical or round body, when subjected to great pressure, tends to collapse into a triangular or “tetrahedral” form. The reason for this is that a “tetrahedron” presents the greatest amount of surface of any body, next to a sphere. A “tetrahedron” is composed of four equilateral triangles, and may readily be constructed by cutting four triangles of the kind out of cardboard, and pasting them together at the edges—when it will be found that you have a top-shaped figure, with a flat surface at the top, and a point at the bottom.

Now, it has been found, by recent researches, that our earth is slightly top-shaped. This is doubtless due to the tendency of the earth to collapse into a tetrahedron, as it cools and contracts—whereas there is also a tendency for the earth to maintain its spherical form, by reason of its rotation.

If the tetrahedron constructed of cardboard be examined, it will be found that the sides are much nearer the center of gravity of the figure than the points; and if water could be made to stay upon the surface of this figure, it would naturally tend to flow onto the smooth sides, leaving the points exposed. These “points” would then be found to correspond, roughly, with the continents or earth-surfaces of our globe, while the oceans would be found to correspond, largely, with the smooth surfaces.

There are, of course, differences to be noted, such as the large land area, which is not to be found on the South Pole, but it is thought that these changes of land and water areas of our globe have been gradually brought about, through millions of years, until they present the approximate surfaces which we note today.

This theory at least explains many facts which before had been puzzling, and there is much to be said in its favor. It was suggested by Mr. Lothian Green, of Cambridge, England.

The question of the sun’s heat is one which concerns us in a very vital manner, since all life upon the earth is directly dependent upon the sun’s radiations, and, were these cut off, all forms of life would soon become extinct.

Until about a hundred years ago, it was thought that the sun was merely an enormous body of fire, and that the heat emitted from it was of the same character as that emitted by a grate of burning coals. This was the chemical theory of the sun’s heat, and it was thought to be no more mysterious than the combustion noted in any furnace—only of course, on a vaster scale!

This purely chemical theory had to be given up when it was shown that, at any ordinary rate of combustion, the heat emitted by even so large a body as the sun would be exhausted in a few tens of thousands of years—whereas the course of evolution on our earth shows us that life has been continuous here for many millions of years, with practically no variation of heat upon the earth surface.

Certainly, therefore, the purely chemical theory of combustion does not suffice, and other theories were accordingly advanced, in attempts to explain the maintenance of the sun’s heat.

It was first of all suggested that, as the sun cools, it contracts, and that this contraction tended to raise the heat, and consequently its temperature would be maintained for a long period of time. But again, it was proved that, if such were the case, the heat of the sun would have been expended millions of years ago.

The theory was then advanced that the sun’s heat was maintained by the impact upon its surface of quantities of meteors and other small bodies which crashed into it—being attracted by the enormous pull of gravitation exerted by the sun. We know that heat is generated by friction or rapid impact, and it was suggested that this might be one of the long period of time. But again, it was proved mathematically that this would entirely fail to account for the continuous and steady heat emitted by our central luminary.

One of the latest theories is that the sun’s heat is maintained by the activity of radium, and that the constant flow of energy which has been noted uninterruptedly for so many millions of years is due to the intra-atomic energy of the atoms composing it. We know that radium can continue to give-off energy for thousands of years, and that even a minute speck of it has a life of extraordinary length. (It has been argued that the heat of our earth is also to some extent maintained by the quantities of radium hidden beneath its surface, in the deeper layers of the earth’s crust.)

Of late, however, even this theory has been questioned, and it must be admitted that, today the heat of the sun remains an unsolved problem. It remains for the future to determine its exact nature and causation.

Men are not naturally adapted to extremely high altitudes, like birds, and consequently, when they rise to great heights suddenly, all sorts of odd things take place. The intense cold numbs them; the low air-pressure forces them to use an artificial supply of oxygen; they become dulled, numb, nervous, dizzy, blind and sometimes unconscious. A detailed study of the changes which take place in the body and mind of the aviator has lately been undertaken, with interesting results.

In its normal state the blood contains about 5,000,000 red corpuscles per cubic millimetre. At great heights, this number is largely increased, that is, “hyper-globia” is produced, becoming more pronounced as the elevation attained becomes higher. The number of the white corpuscles is not augmented.

Respiratory changes are most marked. As the tension of oxygen diminishes the oxygen is more perfectly utilized; but at very great altitudes, the compensation is insufficient, and asphyxiation then commences. Muscular force diminishes, and work at great heights rapidly produces fatigue. At still greater heights, torpor renders work impossible, and the slightest effort becomes very painful.

The sense of hearing is greatly modified, little clicking sounds are often heard in the ears—often noted in the act of swallowing. Visual keenness seems, on the other hand, to be increased. The general sensitiveness diminishes.

In the recent expedition which attempted the ascent of Mount Everest these psycho-physiological changes were carefully studied. In every case it was found that the oxygen content of the arterial blood was lower than at sea level and in equilibrium with the oxygen content of the lung-air. Arterial-blood is from 95 to 100 per cent saturated with oxygen at sea level, but at 14,000 feet where the barometric pressure is 460 instead of 760, which is the normal sea level reading, the blood is from 80 to 90 per cent saturated.

These various effects, coupled with the rapid motion, the roar of the motors, etc., produce in most persons what is known as aeroplane or balloon sickness, identical in character with mountain sickness. It is attended by difficult breathing, loss of appetite, nausea, loss of muscular energy, acceleration of the pulse, venous congestion of the face, headache, drowsiness, etc. Many persons who have taken an aeroplane trip for the first time, anticipating a mere pleasure excursion, have discovered these various symptoms in themselves to their cost! But it is rather late then to “get out and walk!”

Modern improvements in aeroplane construction, however, have largely obviated many of these more serious discomforts, and, of course, in ordinary passenger flights such great altitudes as those here mentioned are not attained. But the changes which take place within man’s body on reaching these great heights are extremely interesting from the medical and physiological point of view.

The discovery of a new comet is always of considerable interest to the scientific world. Professor Baade, of Hamburg, has just announced that he has discovered a new comet in the constellation Cygnus. This comet is too faint to be seen without a telescope, but is rapidly increasing in brightness, and has increased since its discovery from magnitude 115 to magnitude 9. It must, therefore, be rapidly approaching our solar system at great speed.

This question of the velocity of comets is very remarkable, some of them reaching the inconceivable speed of a million miles an hour. Some of them are seen but once in several hundred years, but modern astronomical science is so perfect that it is possible to predict the precise day and hour of a comet’s return, several hundred years hence.

The comet is usually composed of three parts—the nucleus, the coma, and the tail. The nucleus is the bright centre which resembles a star in appearance. The coma is the luminous hood-like envelope by which the nucleus is covered. The tail of the comet is composed of luminous gas, which streams out from the coma sometimes for many millions of miles.

One interesting fact about comets has only been explained of late years, due to the genius of Professor Arrhenius, of Sweden. It had long been noticed that the tail of a comet invariably turns away from the sun—that is to say, as the comet travels across the heavens, the tail turns so that it always streams away from the direction of our central luminary.

Why is this? The explanation is that the light-rays coming from the sun exert a definite physical pressure, and this pressure is sufficient to push the gaseous particles composing the comet’s tail away from it so that the tail is invariably seen to flow away from the sun.

Comets invariably travel in an elliptical course. They come from the vast depths of space, approach our sun, traveling with greater and greater speed as they do so, then “turn tail” (in two senses) and retreat again into the vast depths whence they have emerged. The size of the curve taken by the comet enables the astronomers to calculate the exact date of its return, once they have ascertained the speed with which the body is traveling.

Comets bring home to us, perhaps, more than any other astronomical phenomena, the relative brevity of human life. Some comets return but once in several thousand years. One such was noted a few years ago. When last seen by inhabitants on this earth it must have been before the greatness of Greece and Rome, before the building of the pyramids and the civilization of ancient Egypt! When next it returns, civilizations now existing may have ceased to be! Continents may have been submerged. The whole fate and future of our race may have undergone a profound change. All this in but a single sweep of one body through the vast stretches of stellar space!

Mars is our nearest neighbor, next to the moon, and the question as to whether or not life is possible upon its surface is of interest to us because, with the advent of wireless telegraphy, it is possible that “communication” with beings upon that planet might be some day established—provided they exist!

The so-called “canals” on Mars have long been the subject of popular debate. It has been proved that great fields of ice form at the north and south poles, during the winter time. In spring, these ice-fields melt, and, in view of the scarcity of water on Mars, it has been suggested that the inhabitants of that planet have utilized this supply, by constructing vast canals, which would conduct this water over the surface of their globe, for the purpose of irrigation. It was, of course, pointed out that these canals would have to be miles in width, in order to be visible from our earth. But, to this, it was replied that what is seen are not the canals themselves, but great stretches of vegetation, which exist on either side of the canals, as water flows through them.

The geometrical regularity of these markings seems to point to their construction by thinking beings; but it must be admitted that not all astronomers agree upon this point, and that many of them have been unable to “see” what others claim they have perceived clearly.

The question as to whether living beings like ourselves could exist upon the surface of Mars is in reality part of a larger question, namely—is life possible at all upon its surface? Now, we know that living bodies require water, a certain temperature, and a certain atmosphere in order to render their existence possible. Do these conditions exist upon Mars?

Take, first, the question of temperature. Life is possible only between certain narrow limits. These are the freezing and boiling points of water. The mean, annual temperature on our earth is considerably above the freezing point of water, while the mean annual temperature on Mars falls below it. At the same time, the greatest summer heat is considerably above the freezing point—so that life would be possible at such times. If, therefore, the inhabitants of Mars have somehow learned to keep themselves warm during the long period of cold, it is possible that they might exist upon its surface.

Water is extremely scarce upon Mars. Being a smaller planet than ours, it has dried-up more completely. Our own earth is gradually losing its water supply, and in time will lose it completely. It is because of this fact (that water is so scarce) that the “canals” have been built—provided they are such. The surface of Mars is covered with vast stretches of sandy desert, which give to this planet its characteristic red glow. It is possible, therefore, that, with due economy, the amount of water on Mars might be sufficient to sustain life.

As to its atmosphere, it is much deeper than that of our earth, but might be of a character capable of supporting life.

Scientifically, therefore, it is probable that life on Mars might be possible, and the question remains—is it a fact? Investigations which will be undertaken in 1924 may prove this to us, one way or the other, decisively.

A “day” begins in any particular locality when the sun rises in that place; but officially a day begins at precisely twelve o’clock, midnight, and lasts until midnight, twenty-four hours later, when the next day begins. But this is a shifting point, constantly moving as the earth revolves on its axis, and it will be seen that this would be very unsatisfactory for official science, which would thus have no “check,” so to speak, as to where any particular day actually begins. In order to establish this, what is known as an Official Date Line has been fixed, which is the International Standard for the beginning of each new day.

The meridian running through Greenwich (London) is accepted as the standard meridian; meridians east and west of this are drawn upon the maps, and marked, so many degrees east or west, as the case may be. The 180th meridian (half way round the globe) fortunately falls about the middle of the Pacific Ocean, where there is no land, and this has been settled upon as the international date line. This line is slightly bent, in two places—in the southern hemisphere, to include certain small islands close to New Zealand (so that they may have the same time) and, in the northern hemisphere, it is bent first to the left and then to the right—the former to include certain small islands adjacent to Alaska, and the latter to permit the inclusion of all the main land of Siberia. This may be seen by referring to any map or globe of the world.

While a day at any particular place is twenty-four hours long, each day lasts on earth at least forty-eight hours. Any given day, say Christmas, is first counted as that day just west of the date line. An hour later, Christmas begins 15 degrees west of that line, two hours later it begins 30 degrees west of it, and so on round the globe. The people just west of the date line, who first hailed Christmas, have enjoyed twelve hours of it when it first reaches England, eighteen hours of it when it begins in Central United States, and twenty-four hours of it, or a whole day, when it begins in Western Alaska, just east of the date line. Christmas, then, has existed twenty-four hours on the globe, but, having just begun in Western Alaska, it will tarry twenty-four hours longer among mankind, making forty-eight hours that the day blesses the earth.

If the date line followed the meridian 180 degree without any variation, the total duration of a day would be exactly forty-eight hours as just explained. But this line is quite irregular, as shown on the map. Because of this irregularity of the date line, the same day lasts somewhere on earth about forty-nine hours! Suppose we start at Cape Deshnef, Siberia, longitude 169 degrees West, a moment after midnight on the 3d of July. The 4th of July has begun, and, as midnight sweeps round westward, successive places see the beginning of this day. When it is the 4th in London, it has been the 4th at Cape Deshnef twelve hours and forty-four minutes. When the Glorious Day arrives in New York, it has been seventeen hours and forty-four minutes since it began at Cape Deshnef. When it reaches our most western point on this continent, Attu Island, 173 degrees East, it has been twenty-five hours and twelve minutes since it began at Cape Deshnef. Since it will tarry twenty-four hours at Attu Island, forty-nine hours and twelve minutes will have elapsed since the beginning of the day, until the moment when all places on earth cease to count it that day.

Portions of three days exist at the same time between 11:30 o’clock, a.m., and 12:30 p.m., London time. When it is Monday noon at London, Tuesday has begun at Cape Deshnef, but Monday morning has not yet dawned at Attu Island; nearly half an hour of Sunday still remains there.

Reader, have you a brain? If so, you can be made (apparently) to see it by the following little experiment, which you can try for yourself with no more complicated apparatus than a lighted candle, a black cloth, and a dark room.

Secure a piece of black cloth about three feet square, and pin this onto a wall at such a height that its lowest edge is about on a level with your eyes, when seated or standing, as the case may be. The cloth should be smooth and free from wrinkles. The room should be completely darkened, and a lighted candle should be provided.

The experimenter should then take up his position, about three feet from the black cloth and, while keeping the head level and the chin down, he should elevate the eyes to an angle of about forty-five degrees, so that he is now looking at the centre of the black cloth.

While holding the head and eyes in this position, the lighted candle should be held at a distance of about six inches from the nose—that is to say, the flame of the candle should be about this distance. The candle is now moved slowly across the face, from side to side, at a speed of about two seconds for each movement. The length of the sweep should be about eight inches. Care should be taken, during this process, that you do not blow on the candle flame, as it should be kept as evenly lighted as possible.

If these instructions have been carried out accurately, and the head kept well down with the eyes turned-up, the experimenter will see slowly forming before him in space what appears to be a phantom image of his own brain.

On a pinkish-gray background, he will begin to see innumerable tiny veinings resembling those seen in the leaf of a tree. These are usually black in color, and ramify in all directions unequally. As soon as this image begins to form, the experimenter should keep his eyes fixed upon it, without allowing his eyes to waver in the least. This black ramifying network consists really of the blood vessels, which are seen against the lighter background. It should be noted that only the experimenter himself can see this effect, and that other persons in the room cannot see anything until they try the experiment for themselves. Practically everyone can see it, however, if he will but follow out the directions carefully.

This is, of course, merely an optical illusion. The sight seems to be turned inward, instead of outward, for the time being. Nothing exists objectively in space. It is merely a hallucination, but it is one which corresponds with the inner structure of the eyes and brain.

It has, of course, been claimed that what is really seen is not the brain itself, but the retina at the rear of the eye-ball. It is this which the light of the candle illuminates, and which is actually perceived in the above experiment. As a practical “stunt” for parties, however, it is much more interesting to think that the brain itself is seen in this manner, and in fact what is perceived does very closely resemble the convolutions of the human brain.

Try it for yourself, and see if you do not obtain an interesting result.

Gravitation has always been considered the most mysterious of all forces. It seems to act instantaneously and continually across millions of miles of space, and at the same time holds the atoms of matter together, which are so infinitely small that billions of them could be crowded upon a needle point!

No substance has yet been found which is “opaque” to gravity. One can interpose a screen of some kind, which will shut off light or heat or any of the other energies; but no screen has ever been discovered which is opaque to gravity! For example, glass transmits light, but insulates electricity. A sheet of steel is opaque to light, but is transparent to electricity. But no substance will act as a screen to the pull of gravitation!

The exact nature of gravitation has long been the subject of scientific debate. Various theories have been advanced, but objections exist to them all. Only lately, however, Professor T. J. J. See, government astronomer of Mare Island, California, has advanced the claim that he has discovered the real cause of gravity, and that his theory accounts fully for all known phenomena,—there being no objections against it. If true, this is indeed a revolutionary discovery of great importance, and Professor See’s name will go down in history as one of the greatest scientists of all times!

Briefly stated, his theory is that the pull of gravity consists in a peculiar series of electromagnetic waves, longer than those of light and heat, but closely connected with magnetism. These waves are propagated through space with the speed of light,—that is, 186,000 miles a second, which is the greatest speed ever attainable. These waves are radiated in all directions, from any given mass of matter, and their strength is proportional to the size of any given body.

His theory is that these waves interlace and exert, as it were, a pulling action on each other, in much the same way that two corkscrews, interlaced and twisted in opposite directions, would pull the handles nearer and nearer together. In this way the celestial bodies are really pulled or drawn together, by the action of these interlacing waves.

Professor See also demonstrated before the California Academy of Science, by a series of experiments, that the north and south magnetic poles on our earth are not of the same power. At the Equator, the two poles of the earth’s magnetism are equal; but the magnetic poles are of unequal depth in the earth,—the north pole being 0.76 of the radius downward from Hudson Bay, and the South Pole only 0.66 of the radius downward from King George’s Land, near the South Pole. The result is that, throughout the southern hemisphere, the magnetic force is considerably stronger than the northern hemisphere of our globe.

It remains to be seen whether this theory of gravitation is justified by further experiments.

It is well known that any light created by man wastes a large percentage of its energy in the production of heat. This is plainly noticeable even in our electric light, for the bulb soon becomes hot, when the current is on, and light is produced. Nature is far more economical. She has learned to produce light which is practically 100 per cent efficient, so that almost no heat is generated in its production. This is generally known to science as “cold light,” and is produced by fireflies, glowworms, and certain fish and bacteria, which create this light for themselves whenever they desire.

A prolonged study of this cold light has lately been undertaken, with a view to obtaining it artificially; for, if its secret could be discovered it would have great commercial value, inasmuch as a large percentage of the energy expended in producing the light could be saved. Scientists have accordingly undertaken the study of these light-producing creatures, and much has been discovered concerning them.

In a paper recently read before the Franklin Institute of Philadelphia, Dr. E. Newton Harvey, Professor of Physiology at Princeton, stated that the cold light of the firefly is the result of the combination of oxygen in the air and a substance called “luminiferin.”

This substance is produced by certain glands, specially constructed by nature for the purpose, known as light-organs. They are virtually minute lanterns, and are frequently provided with a special lens, which focuses the light. In the firefly, however, there is no true lens.

The photogenic (light-producing) cells in the firefly contain a mass of granules, spherical in the male, and short rods in the female. Each group of cells is surrounded by a clear ectoplasm containing no granules. Behind this is a layer of special cells which act as reflectors. Air and water are necessary for the production of this light.

Much work has been done upon the chemistry of the luminous substances produced by these living organisms. Two distinct kinds of substances have been detected. These are known respectively as “luciferase,” and “luciferin,” which have quite different properties. The former is unquestionably a protein, and its properties are like those of other albumins. Luciferin, on the other hand, is more closely associated with the peptones and proteoses.

This light, produced by living organisms, may have a variety of uses—such as a warning, to scare away other animals, which would otherwise feed on the luminous organism; or as a sex signal, to bring them together for mating purposes; or merely to be used as lanterns. Many of the deep-sea forms, which live in complete darkness, have no other light, and it is reasonable to suppose that, in their cases at least, living light is used for purposes of illumination.

If the secret of this cold light could be discovered, it would probably save millions of dollars yearly, which is now expended in useless heat-production; for this could be saved, and a much smaller amount of energy utilized in the production of light—in which this energy-loss would not be present.

An elixir of life was one of the things sought by the mediaeval alchemists. Throughout the ages, man has sought a means of prolonging life—and he is still searching!

One of the latest discoveries of modern biological science holds out to us the hope that life may at least be prolonged for a considerable period, and rejuvenated, by a process of grafting portions of certain glands, which serve to stimulate the activities of the body and, to some extent, at least, renew its youth.

It has been shown that the rapidity of growth of the body, and its aging, depend largely upon the vitality of certain ductless glands within it. The secretions of these glands, to a great extent, control the life and death of the body.

Professor Voronoff, of Paris, has succeeded in restoring youth and vigor to several patients by grafting portions of these glands onto the inactive glands in the patient’s body. The portions which have thus been grafted seem to restore the whole gland to a renewed life and vigor, and the health and youth of the subject is thereby largely restored.

These glands have been taken from the higher apes, which are blood relations of man. The demand for apes has consequently increased so enormously that an attempt is now to be made to “corner the market” in apes, and a company has been formed to proceed to Africa, capture a large number of these creatures, and breed them especially for this purpose!

Dr. Voronoff believes that the glands obtained from the ape are better than glands obtained from human beings, since the vitality of the ape is higher and its health is more robust.

It is the secretions of these ductless glands, therefore, to which we must look for our “elixir of life” at the present time, and there seems no reason to doubt that when such operations become simplified, we shall have here a means of extending life and rejuvenating it, in many instances.

It is not known why the human body should die at all, seeing that it is a mechanism which has somehow learned to repair itself. The food we eat is constantly being converted into new tissue, and in this sense it is true that the body of a man of seventy is as young as the body of a baby six months old! Both have been newly made from the food eaten, and yet in one case we have an infant, and in the other, the body of an old man.

Science does not yet know precisely the cause of this, but we are now beginning to suspect that the causes of old age lie in the nature of the secretions of the ductless glands, and particularly the sex glands, and that so long as these are vigorous, youth is maintained, and that when they become devitalized, old age and general degeneration set in.

The importance of these ductless glands, therefore, may readily be seen; and it is possible, in view of this, that, in a generation or two, we shall have “gland-mothers” instead of grandmothers!

Earthquakes, more than any other phenomena, bring home to us the relative insignificance of man, and his helplessness, in the presence of any of the titanic activities of nature. The recent earthquakes which have occurred in Japan have brought this subject to the fore, and have set scientists to work afresh on the study of their causation.

Broadly speaking, it may be said that earthquakes are caused by relatively slight changes in the earth’s crust. The earth is continuously shrinking, and, as it does so, readjustments of the land and water surfaces of the globe take place. When an earthquake occurs under the ocean, this is less noticeable to us, for the reason that the fluid water rapidly adjusts itself to the changed contour of the ocean bed; but land earthquakes are not only more obviously noticeable to us, but cause vast destruction of lives and property.

Certain areas of the land surface of the globe are particularly susceptible to earthquakes. Japan and Central and South America may be mentioned as countries where earthquakes are most frequent. The tremors of earthquakes are transmitted at varying speeds through the earth’s crust, which speeds can be measured by an instrument known as a “Seismograph.” Sometimes these earth-tremors are slight, and are transmitted across only a superficial and limited area of the earth crust. Sometimes they are vast, and are transmitted across practically the whole globe, so that it may be said that in such cases, the whole earth trembles.

Land earthquakes which occur near the seashore or in the ocean-bed near the coast-line are often the most destructive, being followed by tidal waves of enormous height. During an earthquake in Alaska in 1899, the land swayed and waves rose and fell 80 feet every few minutes. Great destruction was wrought up to 40 feet above sea-level.

During a great earthquake shock in 1835, on the Chilean coast the sea retired from the bay, so that sand banks usually from 40 to 50 feet beneath the surface of the sea were exposed. Then a monstrous wave returned 30 feet above high water mark, and swept all before it. This was followed by a second and third, each exceeding the previous one in power, and it was three days before the tremblings of the earth finally came to rest. These shocks were felt 6,000 miles away, and caused violent floods upon islands in the Mid-Pacific. The whole of the ocean oscillated in its bed.

The Carnegie Institute of Washington has recently undertaken the protracted study of the ocean bed along the Chilean coast, with a view to discovering the causes of these earthquakes. The American destroyers—the Hull and the Corry—have been equipped with novel apparatus, by means of which they will make a complete map of the ocean floor along the western American coasts. This apparatus is based upon the invention of Professor Harvey C. Hayes, of the Naval Engineering Station, at Annapolis. It is based upon the principle of the speed with which sound can be reflected from the ocean-bed, so that its depth may be immediately ascertained. In this way a chart can be made of the bottom of the ocean, and possible earthquake-areas readily detected.

The fourth dimension, so-called, has been drawn to the public attention, of late, by reason of the wide publicity given to Prof. Einstein’s theory of Relativity. What is the fourth dimension? How can it be conceived?

The world in which we live is a three-dimensional world. It has length, breadth and height, (Combinations of these). Starting at a given point, draw a line. This is one dimension—length. Move this line at right angles to itself, on a flat surface, and you generate a square—length and breadth. Move this square at right angles to itself, and you generate a cube—adding height. Theoretically, it should be possible to move this cube at right angles to itself, in some direction, and generate a “tesseract” or “hypersolid.” That would be a fourth dimensional figure.

Or again, take a point. Two lines can be drawn through this point at right angles to one another, on a sheet of paper; but if you want to draw a third line through the point, at right angles to the first two, you have to draw it at right angles to the paper itself, as though it were standing up in the air. How can a fourth line be drawn through that point, at right angles to the other three? That would be the fourth dimension.

Theoretically, a fourth dimension is provable, and a great deal is known concerning fourth dimensional geometrical figures. Dr. Manning has written a whole book on the subject: “Geometry of Four Dimensions.” But it is practically impossible for us to conceive the fourth dimension in our minds. We can only arrive at it by analogy.

For instance, a right-hand glove cannot be turned into a left-hand glove; but if it is turned inside out, it becomes one. Similarly, it has been proved that a hollow rubber ball can be turned inside out in the fourth dimension without tearing the ball!

It is impossible to tie a true knot in a piece of string in two dimensions; one end has to be lifted over the other (into the third dimension). And, in our three dimensional space, it is impossible to tie a knot in a piece of string both ends of which have been held or sealed. But Prof. Zollner obtained such knots in the presence of the medium Slade, and this made him believe in the fourth dimension, and caused him to write his famous book “Transcendental Physics.”

Einstein has proposed that time is the fourth dimension, as we know; but this is not a dimension, strictly speaking. This idea has been worked out in some detail, from an original point of view by P. D. Ouspensky, in his ingenious book “Tertium Organum.”

It has been contended that “clairvoyance” is fourth dimensional sight. It is certainly true that, by adding another dimension, we are enabled to see things which would otherwise be invisible. Thus, if you have a box containing some rings, you cannot see the rings so long as the box is kept on a level with the eyes—that is, in two dimensions. But if you elevate your eyes (or lower the box) and look into it from above, you can see the rings inside. That is, by adding another (third) dimension, you are enabled to see what you could not see before, in a “closed” space. Similarly, it has been contended, by adding a fourth dimension, it is possible for clairvoyants to see into what is to us a “closed” room, or closed box, and describe its contents. Of course, this is merely an analogy, which cannot be pressed too far.

While the fourth dimension cannot be visualized by the mind, therefore, a good deal has been learned concerning it, from the theoretical point of view, and mathematically it can be shown to be possible. Its geometry is also well known. The interested reader may find the subject exhaustively treated in Hinton’s books; in the books of Claude Bragdon, and in “The Fourth Dimension Simply Explained,” issued by Munn and Co., New York.

Within the past few years Professor Einstein has made his theory of Relativity famous, but it is probable that the theory itself is not clearly understood by the general public, and the following brief exposition may be of help in this connection.

If you give a boy a piece of apple pie, he may consider it a large piece until you give another boy a bigger slice, when he will at once consider his own small. That is to say it is small relatively to the other piece.

Professor Einstein first brought home to us the fact that all motion in our physical universe is not “absolute” but “relative” motion—that is to say, its speed cannot be measured from any stationary point, for there is no stationary point on our world from which to measure it. The earth on which we live is itself moving on its axis, and that axis “wobbles,” and the earth is also revolving around the sun at a speed of approximately eighteen miles a second, and our whole solar system is rushing through space at an unknown speed!

If one man is on a moving ship, walking up and down the deck, and he passes another man, walking up and down the deck of another boat, moving in another direction, there are all sorts of complicated motions which must be taken into account, and this gives you an idea of the difficulty of obtaining a stationary point, from which to make measurements of other motions (that is to say, matter in motion).

The first point, therefore, is that all motion is merely relative motion; and Einstein also proved that time on bodies moving at different rates of speed was not the same length of time—that is to say, that an “hour” on a body moving at very great velocity was not the same length of time as an hour on one moving at a slower rate of speed. Time is, therefore, only relative, just as motion and space are relative. Both depend upon the velocity of the moving body, and both vary as the speed of that body varies.

These are two of the simplest conclusions of the theory of relativity. There are, of course, many more complicated theories involved within it, into which we have not time to enter now.

The theory itself explains several astronomical phenomena which had been puzzles until the theory was propounded, such as certain minor motions of the planet Mercury. The proof of the theory rests largely upon a certain historical experiment, conducted some years ago, in which it was proved that a beam of light, coming from one of the distant stars, was bent or diverted by the pull of gravity exercised upon it by the sun. Very briefly, the experiment was as follows:

A photographic chart of the heavens having been made, certain stars were found to occupy certain fixed positions when the sun was not present in the heavens. When the sun was present it was, of course, impossible to photograph these stars, because the extreme brightness of the sun prevented the stars from being seen by the eye of the camera. When, however, the sun was eclipsed, these stars could be seen, and during the eclipse of the sun photographs were taken of these same stars and the plates were compared.

It was then found that the position of these stars did not coincide exactly. The stars themselves had not varied relatively to the surrounding stars, as subsequent photographs proved. What, then, had happened? Light rays coming from these stars had been slightly bent or pulled inward by the gravitational pull of the sun! This deviation was exactly that required on the Einstein theory of relativity.

“Impossible,” you say?

Many things may seem to you impossible, which are nevertheless facts! Things which are every-day experiences to us were “impossible” for the last generation. We must be careful before pronouncing that word “impossible.” For, strange as it may seem, this is a simple little experiment which you yourself can perform in a few minutes, with a little apparatus, procured from Mr. Woolworth or any drug store.

If you take an ordinary dish-pan, fill it with water, and drop a piece of ice into it, the ice will of course melt long before the water comes to a boil. But there is a way of doing this so that the ice does not melt, and the water is boiling nevertheless!

Procure, if possible, a “Bunsen burner,” and a few feet of rubber tubing. A Bunsen burner is merely a gas jet with a small hole in the pipe, allowing a certain amount of air to mix with the gas as it burns. In this way, you get a small, pointed flame of gas, hot and blue, like the flame seen on a gas stove. Connect the tube to your gas supply, and light it.

You must have already provided yourself with a glass “test tube,” about eight inches long and a half an inch in width. (This can be obtained for a few cents.) Also a piece of ice about an inch long, and just large enough to fit into the tube; a couple of leaden shot or small weights, and a handle for holding the test tube.

Place the ice in the tube, and drop the shot or weights upon it. Then fill it nearly full of ice-cold water. The weights will keep the piece of ice at the bottom of the tube, and prevent it from floating to the top of the water.

Then hold the test tube, by means of the handle, over the gas flame, at an angle of about forty-five degrees, in such a way that the flame strikes the side of the tube about an inch below the surface of the water. Do not heat the bottom of the tube, containing the ice! (It is best to approach the tube to the flame several times slowly, to prevent the glass from cracking.)

If you have carried out these instructions, you will find that the upper layer of water will be heated, and will boil, giving off steam, whereas the lower portion of the test tube is still cold, and you can invert the tube—when the solid block of ice will tumble out onto the table.

The reason for this is that, whereas solids are heated by what is known as “conduction” (one particle passing on its heat to the next), liquids are heated by “convection” (circulation of the fluids). In this case, no circulation takes place below the spot where the heat was applied, and hence the lower portion of the tube remained cold.

You can see “convection” going on in any ordinary pan or kettle, by dropping a few bits of bran or saw-dust into the water.

By an ingenious device, it is now possible to tell whether a plant, a leaf, a seed, or a piece of organic tissue is living or dead. A sure test for the presence of life is very desirable since it at once informs the experimentalist whether or not the specimen before him can be made to respond, and live again, or not. It is possible that this method may be applied to human beings, in the future.

There are two main tests or signs which all living things show and which are indices of life. One of these is an electrical disturbance. This was discovered more than a hundred years ago. The other is the chemical sign, which has only lately been discovered by Professor Shiro Tashiro, of the University of Chicago.

In a recently published work upon his researches and discoveries in this field, he says:

“It is a matter of very great interest that I have recently found that there is always and everywhere an accompanying chemical change of a particular kind, which is a sure sign of life, and as invariable an accompaniment of the vital reaction as the electrical change.

“This chemical sign is the sudden outburst of carbon dioxide which all living things show—plants as well as animals, dry seeds as well as the nerve tissues of the highest mammals—when they are stimulated in any way. The instrument which I have made to detect this carbon dioxide I have called a “Biometer,” because it is an instrument for the measuring or detecting the amount of life possessed by different things.”

By means of this instrument, it was shown that nerves breathe, that is to say, they take in oxygen and give off carbon dioxide, just as we do. Seeds do the same thing, when they are stimulated; every living thing does so! But the moment that thing is dead, no more carbon dioxide is given off.

The nervous impulses within the body are closely allied to electricity, but they are also chemical in nature, to a great extent. Taking in oxygen and giving off carbon dioxide is essential for their life. The same sort of thing occurs in the human brain; accompanying all thought these transformations take place. Some of these are physical in nature, some vital and some psychical. Professor Tashiro is careful to note this, for the last sentence in his book is:

“Three kinds of nervous changes, then, occur in our brains, when the nerve impulses are passing—an electrical change, a chemical change, and a psychical change. Which is the fundamental change?”

That which makes up our mental life is the psychical change—the thought itself. For us, this is the greatest reality!

Surrounding everybody there is said to be an atmosphere or “aura,” which is radiated from it some distance into space. This is most noticeable about the head, and is said to be the “halo” or “nimbus,” which was portrayed by the old masters about the head of Christ and other holy personages.

Baron Reichenbach made a study of this subject about the middle of the last century, and published an extensive work upon it. His views received no credence, however, and it remained for Dr. Kilner, of St. Thomas’ Hospital, London, to prove scientifically that such an aura exists surrounding every human being.

He perfected a series of slides or screens by means of which this aura can be seen by nearly everybody. A coal-tar product known as “dicyanin” renders the eyes of the on-looker susceptible to vibrations not ordinarily perceived. When the subject is viewed through these slides, the aura may be distinctly seen surrounding the nude body of the subject, who must be placed against a black background in a semi-darkened room.

This misty atmosphere was shown to consist of three layers. First, there is a dark outline, just touching the surface of the body, which he called “the etheric double.” Extending two or three inches into space, beyond this, is a relatively dense layer, known as the “inner aura.” Beyond this, again, is a more tenuous layer, known as the “outer aura.”

This aura extends further in the case of women than in the case of men, and is modified by the physical, mental, and emotional state of subject at the moment. The color and shape of the aura is changed immediately over any diseased spot in the body, and because of this fact, it has been found possible to use the aura as a means of diagnosis.

The precise nature of this human atmosphere is as yet unknown, but Dr. Kilner believes that it is an ultra-violet phenomenon. While it has been seen by many persons, it has not as yet been photographed, but a number of experiments in this direction are being undertaken in the Laboratory of the American Psychical Institute of New York.

There is no aura about dead bodies; the greater the degree of vitality, the further does this aura extend from the body, showing that it is more or less directly dependent upon life. Experiments have shown, also, that both poles of the magnet will attract the aura, showing that it has no polarity.

When the body of the subject is charged with static electricity, the aura slowly vanishes, but after the current has been turned off, it will enlarge to a greater size than before. The radiations of the aura will discharge an electroscope without physical contact.

The vapor of certain chemicals, such as bromine and chlorine, causes the aura to recede, and it is also modified by the thought, will and emotion of the subject. The scientific study of the aura is one of the fascinating fields open to our future scientists.

At the crisis of the Great Revolution, the French Nation—so gifted alike in scientific and artistic talents—determined to make their system of time, length, breadth, weight, etc., a decimal system, so that it would be strictly accurate, in accordance with certain rules, and at the same time as simple as possible. A new calendar was made. The Christian Era was wiped out, and was replaced by the new French era, dating September 22, 1792. Instead of our week of seven days, a week of ten days was established, the tenth day being set apart for rest, like our Sunday. Instead of the mythological names of the month, others deduced from the prevailing seasons of the year were substituted.

Everything was to be reduced to the basis of Reason, which was deified. The Notre Dame was converted into a “Temple of Reason.” Mme. Momero, the young and beautiful wife of a Jacobin printer, was chosen to represent Reason. She was dressed in white, with a mantle of azure blue hanging from her shoulders. Her hair was crowned with a cap of liberty. Adorned in this way, and seated upon a chair decorated with ivy, she was borne, amid the shouts of the people, to the Notre Dame, by four citizens.

It was decreed that the following table should be adopted, and held to be official throughout France:

In order to complete the 365 days of the common year (Sept. 16-22) five “complimentary” days, which were considered festivals, were added.

While such a system doubtless had much to commend it, it speedily fell into neglect, when the new order of things was restored in France and even came in for its share of ridicule. The late George Gates, for example, caricatured the method by the following ludicrous verse: