AN ALPINE EARLY-RISER

WHEN the sun begins to make his heat felt on the snow on the Alps, and the bees are starting on their rounds, there is a little plant down under the snow that wakes up and starts to grow, pushing its flower-buds up through the icy blanket, and blossoming just above the surface. Yes, strange as it may seem, this little flower, the Alpine Soldanella, actually melts its way through snow and ice, so anxious is it to blossom early.

The thick, round leaves of this plant are really storehouses into which, during the previous summer, heating material is gathered, and when, in the early spring, the surface of the snow begins to melt and the water settles down around the plant, an internal heat is generated from this stored material, which, as the buds begin to grow, melts a way for them in the ice. At first, this melted space is the shape of a dome over the starting bud, but as the flower stem lengthens and the bud is raised farther from the ground, the ice again closes about the stem below the bud, and the melted space takes the form of a miniature balloon, or round air-bubble, in the ice. As the stem grows, the bud, surrounded by its protecting bubble of air, gradually moves upward, and thus our ambitious and daring little earlyriser, furnishing its own heat, melts its way up

FLOWERS ABOVE THE

SURFACE OF ICE AND SNOW

great disappointment to the little flower, for its prime object in melting a way to the open air and sunlight is that it may have the assistance of the bees in the setting of its seeds.

GEORGE A. KING.

A FORTUNE IN A TREE THE most valuable tree in the known world is the famous avocado, or alligator-pear, tree, owned by Mr. Harry A. Woodworth, of Whittier, California.

The tree is just eight years old, and this year made $5002 for its owner. Mr. Woodworth has recently had a thirty-foot fence erected around his tree to keep out miscreants, and has had the tree insured against fire and wind with Lloyds, of London, for $30,000. A local nursery-man produced this tree from a seed sent from the Mexican highland. Several more of these seeds were planted at the same time, and have grown into beautiful trees; but none have borne fruit. This tree stands thirty-five feet high, and its trunk is forty-eight inches in circumference. Another peculiar feature about it is that it began bearing when only three years old, as the avocado seldom bears before the age of eight or ten years. The fruit is the shape of a very large pear. It has a very dark green skin and contains one large seed, while the meat is of a creamy

THE TREE PROTECTED AGAINST MARAUDERS.

to become one of the leading industries in California. It is being propagated by thousands; and hundreds of acres are being set out with young avocado-trees.

HENRIETTA A. WOODWORTH.

THE MAGNET AS A USEFUL WIZARD THE principles of the electric magnet have been known since the earliest days of electrical science, and various attempts were made to take advantage of this knowledge for industrial purposes; but it has only been in comparatively recent years that the electro-magnet has entered upon its career as one of the most useful devices for handling raw and finished material in ironand steel-mills, foundries, railroad- and machineshops, and a dozen and one different kinds of manufacturing plants.

Most of us are familiar with the antics performed by iron filings, needles, or small particles of metal when a magnet is pushed within their field; and the construction of small toys that can be moved about by a small horseshoe-magnet has

excited our interest, if not our wonder, by their ready response to the invisible power exerted by this little magician. A magician it surely is, judged purely from an optical point of view!

SEVEN KEGS FILLED WITH NAILS LIFTED BY AN ELECTRO-MAGNET.

A visit to any of our large steel-mills or foundries equipped with electro-magnets would still further impress us with the wizardy of this wonderful device, for there we would see invisible fingers picking up mammoth girders, lifting hot steel plates from the fire, separating pieces of iron from scrap of other metals, pulling and hauling with tremendous power, and always releasing them at the proper moment by a touch of the operator's hand. Their operation is as noiseless as it is swift and sure. There is no clanking and tightening of chains and grappling hooks, no slip of the heavy load as it adjusts itself to the pull, no creaking and groaning of the tacklenothing but swift, sure, and silent lifting and hauling of the weight to its new position.

If we look more carefully, we shall see the electrical magician work further wonders. If it is in a foundry where scrap iron, steel, copper, brass, and other metals are piled together in a

great heap, it will separate the iron and steel from the other metals with a skill surpassing anything else of man's creation. It will sort out and separate these metals from all the others, pulling and hauling at iron and steel pieces lying underneath the brass and copper, and discarding all else with absolute certainty. The foundry, which receives its mixed scrap from all conceivable sources, some of it painted, corroded, and oxidized so that it is difficult to distinguish the different metals without scraping and examining closely, is equipped with a magnetic separator that will do the sorting in a hundredth part of the time required by hand labor.

Although very particular as to what kind of material it will handle, the electric magnet is not at all particular as to how it will manipulate the load. Anything and everything which respond to magnetic attraction that come within its field are picked up. If passed across a scrap-heap, it will gather in its fingers a queer assortment of iron bars, steel shavings, nails, broken pins, and steel rods. It is a queer collection it hauls upa mass of material that to handle singly would require an immense amount of work. Its load is limited only by its lifting power, and that is something enormous in these days, approximating five to twelve tons.

If we take a peep into the rolling-mill, we shall witness other peculiar feats of the lifting-magnet. An enormous hot steel plate or girder must be lifted from its bed to some other part of the mill. To touch this, or even to approach within a foot or two of it, would prove dangerous to the workmen. Formerly, when these hot plates had to be lifted without magnets, the workmen were often severely injured in adjusting the chains. To-day, the electric magnet swoops down and picks up the hot plate, and can transport it to any part of the mill. Its fingers are invulnerable to the scorching heat, and it is in no way concerned whether it is a hot or cold load it is called upon to handle. The magnets with their loads are raised, lowered, and moved about by cables operating from what are known as cranes.

In another part of the rolling-mill, we may see a steel plate forty or more feet long, eight feet in width, and only one half an inch in thickness. Now to lift and carry that to another part of the mill used to be a pretty difficult matter. When lifted, it would bend and buckle under its own weight, and, in order to avoid this, the most careful adjustment of many chains was necessary. But several magnets, used in combination on a single crane, pick up the long, thin sheet of metal, and calmly haul it away to the desired spot. With the exception of a little sagging of the plate be

tween the magnets, you would hardly know that it was being deprived of the support of the ground as it swings silently through the air.

A still further perfection of the industrial magnet may be seen in the handling of the "skull-cracker" by the lifting-magnet. A skullcracker is simply a huge round or pear-shaped ball of iron suspended by a chain and hook. When dropped on big pieces of metal, it breaks and cracks them into small particles for melting purposes. The combination of skull-cracker and magnet works ideally.

Swiftly and surely the huge ball of iron, weighing from twelve thousand to twenty thousand pounds, rises into the air over a scrap-pile and is allowed to fall upon it, smashing the material into convenient sizes. When the contents of the pile have been sufficiently broken up, the pieces are lifted and carried away by the same magnet. Thus a single operator can smash the plates and then pick up the pieces and drop them into the melting-furnace. It is all done so neatly and easily, that it appears more like magic than actuality.

Other uses of the electro-magnet may be seen by visiting a mine where low-grade ores are crushed to obtain the precious metal found in them. When the rocks are crushed and pulverized by the machinery, the magnets are used for picking up the small particles of iron from the ores. By this method of ore-separation, old tailings, that were formerly discarded as worthless, have been made of great value. The iron ore recovered is of sufficient value to build up great industries. Before the big commercial magnets were utilized, all of this low-grade ore was practically wasted.

Next take a peep at a flour-mill or a factory where rice chaff is ground into small particles to make cattle food. Enormous attrition machines are used for grinding the chaff, and they consist of two metal disks revolving in opposite directions. These disks are separated by one eighth to three sixteenths of an inch.

The disks are indented to give a grinding surface, and they make from 1500 to 2000 revolutions per minute. Now, if a small particle of iron or steel should be caught between these revolving disks, a hot spark would be generated. Many times hot sparks produced in this way have caused disastrous fires by igniting the light, combustible chaff. In flour-mills, disastrous explosions have been due to the same cause. The fine dust which collects in flour-mills will sometimes explode almost as violently as gunpowder, if a spark is applied to it when suspended in the air.

The use of electric magnets has eliminated the

danger of both fire and explosions in these industries. Strong magnets are placed in the attrition machines so that all the chaff must pass in close proximity to them before it reaches the grinding disks. These magnets are powerful enough to draw out any bits of iron that may be mixed in the chaff. Similar contrivances are used in flour-mills, and they have reduced the danger of explosions and fires from this cause almost to a minimum. Sometimes a collection of nearly a pound of small pieces of iron is re

abundant instances of the remarkable value of the device. For example, a load which had required two men four hours to place in a wagon, was lifted from the same wagon and placed in the storage pile by a magnet in just two and one half

Courtesy of Cutler-Hammer Clutch Co.

52-INCH MAGNET, LIFTING A SKULL-CRACKER BALL.

minutes. As a rule, one electric lifting-magnet does the work of a gang of from six to twelve workmen, and the mode of operation is so simple that only one man is needed to manipulate two or three magnets. By means of a simple device, the operator can regulate the current and power of the magnet so that he can pick up one, or two, or any number of pieces at once. If a small beam lies alongside of a larger one, and it

is desired to move only the former, the current is proportioned to the lesser weight, and the magnet lifts it without disturbing the heavier one. Thus, in the hands of a skilled operator, the magnet performs the work of sorting and lifting different weights with almost uncanny intelligence. It rejects this piece from a heap, throws another out of the way, and finally picks up the one it has been searching for. In foundries, steel-mills, ship-building yards, and railroad machine-shops, the big electric magnets are continually working, performing jobs of a difficult nature that were formerly done by hand, or by tackle and chain.

When the lifting-magnets were first introduced in our big mills, it was urged against them that there was always the danger of a failing current and the sudden release of the load, when, it was feared, serious injuries would result to the workmen by the fall. But experience has shown that this danger is not to be greatly feared. Indeed, no more accidents or delays have been caused by a failing current than had been due to the slipping of chains and hooks. In handling enormous weights of this character, there is always present the element of danger, and only care and precaution can eliminate it entirely. The rule in most shops and mills is that no workmen shall pass or stand under the heavy loads carried by cranes and magnets.

Electro-magnets in general use in mills and shops differ a good deal in design. The oldest and most popular form was the simple horseshoe. This type has proved inadequate for plate-handling and for many other grades of work. In the effort to secure the most efficient design, the round magnet was developed, which, for handling certain kinds of compact loads, is unsurpassed. But experience showed that, while a round magnet in a straight pull could easily lift five tons, it was incapable of picking up a long, thin plate weighing only half a ton. As a result of this experience, the engineers designed a special platehandling magnet.

rate.

The design and construction of the magnet for lifting heavy weights must be exact and accuSuch magnets are proof against heat or cold, and there is practically no danger of accidental short-circuiting. The winding of the coils is the most expensive part of the construction of the giant magnets. In the round type of magnet, there may be as high as three thousand turns of wire, weighing approximately 220 pounds.

Small magnets are employed by manufacturing concerns with as great success as the larger ones are used in the mills and shops. For instance, in needle factories small magnets are used at the