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ADAPTING THE "OLD OAKEN BUCKET" FOR USE IN BAILING OUT COAL-MINES

BAILING OUT A COAL-MINE

ONE of the great bugbears of the coal-miner is water. In fact, it was the crying need of some means of ridding collieries of water that inspired Newcomen to build the first steamengine in 1705; and forty years later, when James Watt turned his attention to steam power, he had the pumping-out of mines as his first object. The British coal-mines are for the most part located below sea-level, and some of them extend far out under the very bed of the ocean. In these mines, there is a continuous battle with water, and were not the pumps worked constantly day and night, the mines would soon be drowned out.

Fortunately, in the United States the coalmines are far removed from the sea-coast, and the coal-beds, in most cases, are not far below the surface, so that we are not bothered with water to the same extent as are our British cousins. However, there are some mines in the anthracite regions of Pennsylvania that run down to a considerable depth and encounter a great deal of water. Strange as it may seem, the water in these mines is not pumped out. Raising water five hundred to a thousand feet with a pump is not so simple as it sounds. A suction-pump will raise water only a little over thirty feet. For greater heights of lift, a force-pump may be used, or an air-lift. In the latter case, compressed air is let into the bottom of the water-pipe, and the air bubbles carry the water up with them. But instead of using any such systems in deep mines, the simple expedient is used of bailing out the mine with buckets. The mine

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These tanks are enormous. Some of them are nearly six feet in diameter and almost thirty feet high over all, about ten feet of which is taken up by the spouts. Such a tank will hold about fifteen tons of water, and the tank itself will weigh eight or nine tons more. The hoisting-cable will weigh some three tons per thousand feet, so that, as it starts up from the bottom of the shaft, there is a load of between twenty-six and twenty-seven tons to be hoisted. The empty bucket running down reduces the load to about eighteen tons. A special shaft is excavated for the water-hoist, and this runs down below the mine level to form a sump. Here the water collects from a special drainage-tunnel.

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THE TRAVELER'S TREE

IN front of the "Direction" at the Botanical Garden of Eala (Belgian Congo) stands a beautiful sample of Revanella madagascariensis, which, in the warm lands, is called the traveler's tree.

As its botanical name suggests, its country of origin is Madagascar, but it may be grown anywhere under the tropics, provided the atmosphere be not too dry. Yet it is not frequently found, consequently its most uncommon and highly interesting particularities are but little known.

The bearing of the tree is very elegant; its leaves are disposed all in a row bending gracefully outward; and when it is planted a little sideways on the edge of a vista, where all the movements of its leaves can be observed, it looks the marvel it really is. Its appearance of a half-opened fan is quite unique and so striking that it is sufficient to see it only once in order never to forget it. To produce this fanlike appearance, at least twenty good leaves are required, so that young plants are not nearly so handsome. But twenty leaves are about as much as a tree will carry, because older ones disappear as new ones are formed. These new leaves are produced from the center of the fan, one to the right and one to the left, alternately; they are disposed face to face and grow right up, but are gradually pushed to the side by newer leaves that come up. The

THE TRAVELER'S TREE AT THE BOTANICAL GARDEN OF EALA IN THE BELGIAN CONGO

whole fabric is not as fragile as it appears, for it will stand strong winds and even hurricanes very well, thanks to the semi-solid, fibrous material of which the stem is composed, and to the marvelous elasticity of the leaf stems. The limbs naturally get torn in time, as banana leaves do, the new ones being still nearly intact while the older ones are completely cut to fringes, but they last sufficiently long to perform their duty.

The limb of the leaves closely resembles that of the Chinese banana-plant, but the whole differs from it in this respect, that here it is borne on a stem which is longer than the limb itself, while the limb of the banana leaf starts straight away from the stem of the plant.

The leaf stems end in a curved, much-widened-out part, the borders of which are packed so tightly together that from the outside they seem to form a diamond-shaped, solid mass from which the leaf stems spring. This, however, is not so, for each leaf extends to the tree stem, which it embraces completely, so that it is very securely inserted.

As these enlarged parts are curved, there remains a space between each two leaves. This may hold so much water that when one of the lower leaves is cut from a big tree, nearly a pint of it may be found there, with which an exhausted traveler may quench his thirst. From this fact, the tree derives its name. There is no other tree which stores water like this, which makes it one of the marvels of the vegetable kingdom.

The traveler's tree, however, possesses another property which, not unfrequently, causes its doom. It attracts lightning more than other trees do. This must probably be ascribed to the special bearing of the tree, which has no side branches, but whose leaves are all pointed the same way, in one line. And as it hardly ever survives the stroke, it is

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acquainted this month with the beautiful and more interesting constellation of Perseus, the hero of mythical fame to whom we referred last month in connection with the legend concerning Cepheus and Cassiopeia, the king and queen, Andromeda their daughter, chained to the rocks to be devoured by the sea-monster, and Pegasus the winged horse that bore Perseus to the rescue. Cetus, you will recall, represents the approaching monster of the deep. We have included the constellation of Andromeda in our diagram for this month, since it is so closely associated in legend with the constellations of Perseus and Cetus, though we also showed it last month in connection with Pegasus.

The brightest star in Perseus, known as Alpha Persei, is at the center of a curved line of stars that is concave or hollow toward the northeast. This line of stars is called the Segment of Perseus, and it lies along the path of the Milky Way, which passes from this point in a northwesterly direction into Cassiopeia. According to the legend, Perseus, in his great haste to rescue the maiden from Cetus, the monster, stirred up a great dust, which is represented by the numberless faint stars in the Milky Way at this point. This star Alpha is, by the way, in the midst of one of the finest regions of the heavens for the possessor of a good fieldglass or small telescope.

A short distance to the southwest of Alpha is one of the most interesting objects in the heavens. To the ancients, it represented the baleful, winking demon-eye in the head of the snaky-locked Gorgon, Medusa, whom Perseus vanquished in one of his earliest exploits and whose head he carried in his hand at the time of the rescue of Andromeda. To the astronomers, however, Algol is known as Beta Persei, a star that they have found consists of two stars revolving about each other and separated by a distance not much greater than their own diameters. One of the stars is so faint that we speak of it as a dark star, though it does emit a faint light. Once in every revolution the faint star passes directly between us and the bright star and partly eclipses it, shutting off five sixths of its light. This happens with great regularity once in a little less than three days. It is for this reason that Algol varies in brightness in this period. There are a number of stars that vary in brightness for the same reason. Their periods of light-change are all very short, and the astronomers call them eclipsing variables. We can observe for ourselves

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new star as brilliant as the pole-star. On the following day it became a magnificent star of the first magnitude. A day later it had lost a third of its light, and in a few weeks it was invisible without the aid of a telescope. In a year it was invisible in all except the most powerful telescopes. With such telescopes, it may still be seen as a very faint star surrounded by a faint, nebulous light.

Triangulum and Aries are two rather inconspicuous constellations that lie on, or close to, the meridian at this time. There is nothing remarkable about either of these groups, except that Aries is one of the twelve zodiacal constellations, so called because they lie in that belt of the heavens known as the zodiac, in which the sun, moon, and planets are always to be found. Some centuries ago, the sun was always to be found in Aries at the beginning of spring when it crossed the equator going north, and the position it occupied in the sky at that time was called the First Point in Aries. This

point is gradually shifting westward, however, at a very slow rate, and now at the beginning of spring the sun is to be found in Pisces instead of Aries, and it does not enter Aries until later in the spring. Pisces, you will recall, was one of our constellations for last month, and we showed in that constellation the present position of the sun at the beginning of spring.

Two stars in Aries, Alpha and Beta, are fairly bright, Alpha being fully as bright as the brightest star in Andromeda. Beta lies a short distance to the southwest of Alpha, and a little to the southwest of Beta is Gamma, the three stars forming a short curved line of stars that distinguishes this constellation from other groups. The remaining stars in Aries are all faint.

Just south of Aries lies the head of Cetus, The Whale. This is an enormous constellation that extends far to the southwest, below a part of Pisces which runs in between Andromeda and Cetus. Its brightest star, Beta, Diphda, or Deneb Kaitos, as it is severally called, stands quite alone not far above the southwestern horizon. It is almost due south of the star in Andromeda that is farthest to the west, which it exactly equals in brightness. The head is marked by a fivesided figure composed of stars that are all faint with the single exception of Alpha, which is fairly bright, though inferior to Beta in brightness.

Cetus, though made up chiefly of faint stars, and on the whole uninteresting, contains one of the most remarkable objects in the heavens, the star known as Ŏ'micron Ceti or Mi'ra (The Wonderful). This star suddenly rises from invisibility nearly to the brightness of a first-magnitude star for a short period once every eleven months. Mira was the first-known variable star. Its remarkable periodic change in brightness was discovered by Fabricius in the year 1596, so its peculiar behavior has been under observation for three hundred and twenty-five years. It is called a long-period variable star, because its variations of light take place in a period of months instead of a few hours or days, as is the case with such stars as Algol. Mira is not only a wonderful star, it is a mysterious star as well, for the cause of its light changes are not known, as in the case of Algol where the loss of light is due to a dark star passing in front of a brighter star. Mira is a deep-red star, as are all long-period variable stars that vary somewhat irregularly in brightness. It is visible without a tele

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scope for only one month or six weeks out of the eleven months. During the remainder of the eleven months, it sometimes loses so much of its light that it can not be found with telescopes of considerable size. Its periods of light-change are quite variable at times, as is also the amount of light it gains at different appearances.

It is believed that the cause of light changes of Mira is to be found within the star itself. It has been thought that dense clouds of vapors may surround these comparatively cool, red stars and that the imprisoned heat finally bursts through these vapors and we see for a short time the glowing gases below; and then the vapors once more collect for a long period, which is followed again by another sudden outburst of heat and light.

It is interesting to remember in this connection that our own sun has been found to be slightly variable in the amount of light and heat that it gives forth at different times, and the cause of its changes in light and heat are also believed to lie within the sun itself.

As in the past few months, no planets are to be seen in the evening skies.

ISABEL M. LEWIS.

THE WONDER OF THE WATCH HAVE you ever thought what a marvelous little machine you have in your watch? There are at least one hundred and seventyfive different parts in the make-up of the watch. No less than two thousand and four hundred distinct operations have to be gone through during the process of manufacture. But even more wonderful are these few astonishing facts about it.

Have you ever watched a blacksmith at work and wondered how many blows he strikes on his anvil in the course of the day? On a very busy day, the number will only be several hundred. Compare this performance with what the watch does. Each day the roller-jewel of the watch makes 432,000 blows against the fork, or 157,680,000 in the course of a year. This goes on without a single rest if the watch is in good order. If a watch were to go for twenty years, it would give some 3,153,600,000 blows during that period.

It has been reckoned that the power that moves the watch is only four times the force used in a flea's jump. We might therefore say that one watch-power is equivalent to four flea-power. How small is the power will be gathered when it is realized that one horse-power would be sufficient to operate 270,000,000 watches.

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