The Wonder Book Of Knowledge Part 22

In good climates it bears two crops in a season; one in the early summer, from the buds of the last year; the other, which is the chief harvest, in the autumn, from those on the spring growth.

Figs, particularly dried figs, form an important article of food in the countries of the Levant, and are exported in large quant.i.ties to America and Europe. The best come from Turkey.

What are "Fighting Fish"?

Fighting fish are a small fish and belong to the climbing perch family.

They are natives of the southeast of Asia and are remarkable for their pugnacious propensities.

In Siam these fish are kept in gla.s.s globes, as we keep goldfish, for the purpose of fighting, and an extravagant amount of gambling takes place about the result of the fights.

When the fish is quiet its colors are dull, but when it is irritated it glows with metallic splendor.

How is the Exact Color of the Sky Determined?

An instrument called a "cyanometer," meaning "measurer of blue," is used for ascertaining the intensity of color in the sky.

It consists of a circular piece of metal or pasteboard, with a band divided by radii into fifty-one portions, each of which is painted with a shade of blue, beginning with the deepest, not distinguishable from black, and decreasing gradually to the lightest, not distinguishable from white. The observer holds this up between himself and the sky, turning it gradually round till he finds the tint of the instrument exactly corresponding to the tint of the sky.

What is a "Divining Rod"?

A divining rod is a wand or twig of hazel or willow used especially for discovering metallic deposits or water beneath the earth's surface.

It is described in a book written in 1546 and it has also a modern interest, which is set forth by Prof. W. F. Barrett, F.R.S., the chief modern investigator. The use of the divining rod at the present day is almost wholly confined to water finding, and in the hands of certain persons it undoubtedly has produced results along this line that are remarkable, to say the least. The professional water-finder provides himself with a forked twig, of hazel, for instance, which twig, held in balanced equilibrium in his hands, moves with a sudden and often violent motion, giving to the onlooker the impression of life within the twig itself. This apparent vitality of the twig is the means whereby the water-finder is led to the place where he claims underground water to exist, though its presence at that particular spot was. .h.i.therto wholly unsuspected. While failure is sometimes the outcome of the water-finder's attempts, success as often and, indeed, according to the testimony of Professor Barrett, more often crowns his efforts. Various explanations, scientific and other, of the phenomenon have been advanced. Professor Barrett ascribes it to "motor-automatism" on the part of the manipulator of the divining rod, that is, a reflex action excited by some stimulus upon his mind, which may be either a sub-conscious suggestion or an actual impression. He a.s.serts that the function of the forked twig in the hands of the water-finder may be to act as an indicator of some material or other mental disturbance within him. While a hazel or willow twig seems to be preferred by the professional water-finders, twigs from the beech, holly or any other tree are employed; sometimes even a piece of wire or watch spring is used, with apparently as good results.

The Story of Electricity in the Home[13]

How wonderful to youth always has been the magical story of Aladdin and the wonderful lamp which, through its supernatural powers, he could gently stroke and thereby make genii of the unknown world his slaves.

In the rush of modern affairs there is that which is even more fascinating, even more wonderful, than the story of Aladdin and the magical power exerted through his lamp, but which is given but a pa.s.sing thought because of the rapid changes through which we are pa.s.sing.

Mythical as it may sound, yet nevertheless it is true, that man has harnessed for his use every snowflake that falls in the mountain tops and settles itself in the banks of perpetual ice and snow. How man has tapped the mountain fastnesses and converted the melting snows into a servant more powerful, more magical, more easily controlled, than Aladdin's genii, should be known to everyone. This servant is electricity.

This silent, invisible servant is ever present, always ready at the touch of a b.u.t.ton or the snap of a switch, without hesitation, without grumbling, to do silently, swiftly, without dirt, without discomfort, without asking for a day off or for higher wages, the work which is laid out for it.

The use of electricity is so common today that the average person does not stop to think of it as a magical power wielding a tremendous influence for betterment in every-day affairs.

Electricity has rapidly found its way into the home for domestic purposes, eliminating at its entrance a host of cares of the household.

So recently, as to seem almost yesterday, the genius of man's brain coupled electricity with mechanical devices for the comfort and efficiency of the home.

Although a number of attempts have been made to build appliances for use in the home that would utilize electricity, the real beginning of the present almost universal use of electrical appliances seems to have been in the manufacture of the electric iron. One instance, at least, coupled with the manufacture of this household necessity, offers something of romanticism.

To a certain western state, a young electrical engineer betook himself, obtaining a position as superintendent of an electric power company and establishing his abode in a tent far up a canyon, more for the benefit of his wife's health than for the thought of being near the power plant and his work. The melting snow which gathered in little rivulets made a roaring mountain stream which generated such an excess of power for the company, that the young electrical engineer began looking about for other means of utilizing it than for lighting the homes of the villages below the mouth of the canyon. He designed a crude electric iron, placed a number of them in use, and found they gave fairly good service and at the same time enabled the power company to sell additional current.

Development of the device was rapid, so rapid, in fact, that the young engineer's time was soon taken up with it and he resigned from his position with the power company to organize a small concern for the purpose of manufacturing electric irons which at first were sold to the consumers of the power company and later to a large nearby city.

These irons met with such a ready reception and were so popular with housewives because of the time saving and the convenience, that attention was next turned to other appliances which could be used in the home and which would a.s.sist the power company in the sale of current.

About one hundred electric cooking sets were manufactured, consisting of ovens and crude round stoves. These were distributed among the customers of the power company and thenceforth their operation was carefully watched and improvements made from time to time, using always the suggestions offered by the housewives to make an appliance that would meet the needs of the home.

This particular company, which was started but little more than ten years ago in a small room of a store building in a small town of Southern California, has grown rapidly from that time when its complete office and factory force consisted of a man and two boys. It now places in homes well toward a million appliances each year.

Since the home can now be operated almost exclusively with electrical appliances, including everything from the electric iron to the modern labor-saving electric range, it is well to note briefly some of the many reasons for the success of electrically-heated appliances.

Perhaps most noticeable is cleanliness and the absolute absence of dirt and grime in using pure electric heat. There is no soot, no smoke nor discoloration. There are none of the bad effects so often caused by the air becoming vitiated, due to the burning up of oxygen in the air by gas and other fuels. There is no corrosion, oxidization or other form of deterioration.

Perfect and absolute control of heat seems to be secured. The easy snap of the controlling switch on the electric burner gives a certain intensity of heat which remains at that temperature so long as the switch remains in that position. Thus, with modern appliances, the housewife operates them at high, medium or low to suit her desires.

[Ill.u.s.tration: ORIGINAL ELECTRIC IRON]

Fire risk is reduced to a minimum, because there are no matches, no kindlings, no kerosene cans, no oil barrels and nothing of the sort to endanger life and property.

The efficiency obtained through the operation of electrical appliances soon becomes evident to the user. The heat generated for ironing, for instance, is all utilized. This is true as well with heating or cooking appliances, and this utilization of practically all of the heat units naturally results in economy in operation in communities where the lighting or power company has made a favorable rate.

Because the electric iron seems to have been the forerunner of electrical appliances for the home, it is well first to describe briefly the processes of manufacture necessary before the iron can be placed in the home and take its position as one of the modern labor-saving devices.

One of the first irons to be manufactured, an ill.u.s.tration of which is shown herewith, did not offer the pleasing appearance nor give the service of its youngest sister, the ill.u.s.tration of which is also shown.

One of the first problems was to control the heat at the iron, and to do this a separable switch plug was developed, enabling the operator to connect or disconnect the current supply at the iron.

The real problem, the one of most vital importance from the point of efficiency, was that of the heating element that would do more than heat the center of the sole plate. One of the pioneer manufacturers, after numerous experiments, concluded that, since the point or nose of an iron comes first in contact with the damp goods, naturally it should have first and most heat applied to it. The result was a double heating element in the form of a V, the resistance wire used being symmetrically wound on a flat, thin mica core. This V-shaped element, the point of the V coming up into the nose of the iron, insured a hot point, as well as hot sides, center, back and heel, where the terminals were connected with the switch plug receptacle. Another development which followed was that of an attached stand, eliminating the necessity of lifting the iron on and off a stand many times during the ironing. At first the iron was heavy and clumsy, being built of cast iron, but modern manufacture has made it possible to build the sole plate of cast iron and the top of pressed steel.

[Ill.u.s.tration: ELECTRIC IRONS, 1916]

[Ill.u.s.tration: FIG. 1.--POURING MOLTEN METAL INTO MOLDS FOR CASTING IRON SOLE PLATES]

[Ill.u.s.tration: FIG. 2.--WORKMAN POLISHING SOLE PLATES]

The ill.u.s.trations show some of the steps necessary before the iron reaches the shipping room. Fig. 1 shows the workman pouring an earthen ladle of molten metal into the molds in which the sole plates are cast.

Fig. 2 shows the sole plate in the hands of the workman, held against a rapidly revolving polishing wheel, after it has been run through a milling machine and ground to a perfect size. Fig. 3 shows a huge punch press which cuts the blank of steel that is afterwards drawn to the shape of the iron top. The workman is seen holding in his hand the blank cut from a sheet of steel (Fig. 4). The blanks of flat steel of such irregular shape are next pa.s.sed to a mammoth draw press which draws blanks into the perfect shape to be fitted over the top of the pressure plate which holds the heating element firmly against the sole plate. At the operator's left hand is a stack of blanks and in his left hand he holds one ready to be placed in the draw press. In his right hand is a top just pulled from the press, and at the extreme right a large truck full of finished tops ready for the polishing wheels.

Mica, which so many people know as isingla.s.s, is one of the most important materials in the manufacture of the standard electric iron.

The highest grade mica comes from India and the open box in the picture shows thin, transparent pieces just tumbled out (Fig. 5). At the edge of the table is a stack of mica strips known as cores. Hanging over the top of the board are several cores on which the resistance wire has been wound, showing the V-shaped heating element.

[Ill.u.s.tration: FIG. 3.--BLANKING THE STEEL TOPS]

One of the most important and yet seemingly simple parts of an electric iron is the switch plug which connects the electric light socket with the iron. The operator in Fig. 6 is shown a.s.sembling switch plugs and is in the act of driving home a screw which holds in place the fiber bar over which the cord bends.

[Ill.u.s.tration: FIG. 4.--DRAWING THE BLANKS INTO THE PERFECTLY SHAPED TOPS]

[Ill.u.s.tration: FIG. 5.--SHOWING A BOX OF IMPORTED MICA

Above on the table, a stack of "cores" and several elements ready for insertion in the iron. Notice the V shape.]