Part 85

The Le Prince camera was therefore the real parent from which the modern motion-picture camera sprang. The first really modern motion-picture camera was built in a single case with a battery of sixteen separate lenses and sixteen shutters. These were operated by turning a crank. The pictures were taken on four strips of film. When the crank was turned the exposure was made to each of the sixteen lenses in succession, and when the series was completed the films were cut apart and pasted together in a single strip of film, the pictures themselves being arranged in the proper order. The principal development of this camera, as found in the present method of making motion pictures, is the invention of the flexible film negatives; the transparent support for the print which permits the pictures to be projected in enlarged form upon a screen; and the system of holes in the margin of the film by which the film is held in perfect alignment for projecting the pictures.

But a few years ago, then, the motion picture was a child’s toy. To-day it forms the basis for not only a very large and profitable business for many people, but a source of amusement and education to millions of people at reasonable prices. To-day the motion-picture business is regarded as one of the world’s greatest industries.

No corner of the world is so far remote but the motion-picture man finds his way there, either as an exhibitor or as a producer. Nothing happens in the world to-day but the motion-picture man with his camera is on the job if it is a happening that can be preserved in motion pictures and worthy of that. The dethronement of kings and the inaugurations of presidents are all alike to him. If there is a war, he is found in all parts of the field, and is the first to see the parade when there is a peace jubilee. Disasters, horrors, heroes and criminals pass before his lens and he gives us a moving panorama of everything that is interesting, in nature, in real life, and in fiction.

Taking Motion Pictures a Simple Operation.

Motion-picture photography is mechanically simple and the projection of the pictures on the screen was made possible by the improvement in dry plates which made instantaneous photography successful, together with the invention of the process of using celluloid films for negatives. Motion pictures consist of a series of photographs made rapidly and then projected rapidly on the screen. In this way one picture follows another so quickly that the change from one picture to another is not noticed and the movements and actions of the persons or things photographed are reproduced in a life-like manner.

Is the Hand Quicker Than the Eye?

There is no question that the hand can be moved so quickly that the eye cannot detect the movement. This is proved by the motion picture when projected on the screen. In moving pictures the quickness of the machine deceives the eye and the transition from one picture to another is done so rapidly that the change is not seen and the apparent movement is continuous and unbroken.

The film made by the motion picture is a “negative” in which the colors are reversed, the blacks being white and the whites black, exactly as in still photography. The film used in the projection machine is a “positive,” in which the lights and shadows have their proper values. The principle and process is exactly the same as in making lantern slides and window transparencies.

Does the Film Move Continuously?

In making the negative for the motion picture the film does not move forward regularly, but it goes by jumps. It is absolutely still at the moment of exposure. The same is true in projecting the picture on the screen. In most projection machines the film is stationary three times as long as it is in motion, though in some machines the proportion is one in six. In the taking of the picture, the film is really stationary one-half of the time. As pictures are usually projected at the rate of fourteen or sixteen to the second, this means that each separate picture appears on the screen three-fourths of one-sixteenth of a second, or three-sixty-fourths of a second, and

How Are Freak Pictures Made?

Freak pictures are usually the result of clever manipulation of the camera or the film. Articles or individuals can be made to instantly disappear by stopping the camera while the article is removed or the person walks off the stage, the other characters holding their pose until the camera is again put in motion. In some films in which a person is thrown from a height or is apparently crushed under a steam roller the effect is gained by the live person walking away after the camera is stopped and a dummy substituted to undergo the death penalty.

By projecting the picture at a faster rate than it was taken, excruciatingly comic scenes are sometimes devised. An automobile going ten miles an hour, by speeding up the projection machine, may be made to apparently move at a hundred miles an hour, and by increasing in the same way the apparent speed of persons dodging the demoniac auto exceedingly ludicrous effects are had.

By mechanical means in combining two or more negatives into one positive a man can be shown fencing with himself or even cutting his own head off.

Pictures by courtesy of the Vitagraph Company.

WASH ROOM.]

These and the following Pictures by courtesy of the Goodyear Tire and Rubber Co.

The Story in a Ball of Rubber

How Crude Rubber Is Treated.

Washing.--When the crude rubber arrives at the factory of the rubber manufacturer, it is generally stored in bins in dark and fairly cool store-rooms, where it is kept until ready to be used. The rubber passes directly from the storage bins to the wash-room, where it is cut up into small pieces, put into large vats of warmed water and allowed to soak, in order to soften it sufficiently to be broken down in the machines. It is then fed into a cracker, a machine consisting of two rolls with projections on their surfaces shaped like little pyramids, the two rolls revolving with a differential, one going considerably faster than the other, and being adjustable, so that they can work close together or with some distance between them. The rubber is fed between these rolls and broken down into a coarse, spongy mass. Water flows on to the rubber during the process, bringing down sand, dirt, bark, and the many other foreign materials which come mixed with the rubber. The rubber is put through this machine a number of times, until it is worked into a uniform condition. Some of the rubbers, like the Ceylons and Paras, will sheet out into a coarse sheet by being put through this machine; others, like the majority of the African rubbers, will fall apart and come down in chunks and have to be fed into the machine with a shovel.

CALENDER ROOM.]

After the rubber is broken down sufficiently in the cracker, it is next put through a washing machine, which is built very similar to the cracking machine, except that the rolls are grooved or rifled, so that their action is not so severe on the rubber. A large quantity of water is kept constantly running over this machine while the rubber is being put through, and the rolls work very close together, so that the rubber is finely ground and run out into a thin and comparatively smooth sheet, allowing the water flowing between the rolls to take out practically all of the foreign matter that remains. The rubber is run through this machine a number of times until the experienced inspectors in charge are satisfied that it is thoroughly washed. Some types of rubber, such as Manicoba, which have large quantities of sand in them, are washed in a special form of washing machine known as the beater washer. This is an endless, oval-shaped trough with a fast-revolving paddle-wheel. In this machine the rubber is submerged in water, after being broken down in the cracker, and the sand is literally knocked out of it by the paddle-wheel. The sand drops to the bottom of the machine, where if is drained off, while the rubber floats to the top and is there gathered and then put through a regular washing machine for the final sheeting out.

Drying.--From the wash-room the rubber goes to the dry-room. Before the rubber can be used in any articles of commercial value, it must be thoroughly dried, as any moisture in the stock would turn to steam during the vulcanizing process and cause blisters or blow-holes to form in the goods. There are two ways in which rubber is usually dried. The method mostly used, and which is generally practiced with all the better grades of gums, is to hang the washed strips on horizontal poles and space them in aisles, so that air can freely circulate all around the surface of the rubber, the dry-room being kept at a constant temperature. To properly dry the rubbers by this method takes from four to six weeks. The other method of drying is by means of a vacuum-drier. Low-grade rubbers which have a comparatively large percentage of resin in their composition cannot bear their own weight when hung on horizontal poles, but drop off and stick in piles on the floor. Hence, these rubbers have to be dried in a peculiar manner. They are laid in trays which are placed into a large air-tight receptacle. The air is then withdrawn from this receptacle and the interior heated by means of steam coils. This allows the water to be evaporated off from the rubber at a considerably lower temperature than that at which water boils under atmospheric pressure, and at such a low temperature, and in such a short time, that the rubber is not affected. By this process these rubbers can be dried in a few hours.

Mixing.--After the rubber has been thoroughly dried, it is ready to be mixed in proper proportions with the various ingredients which are used in rubber compounding, to give the desired quality of rubbers for the various products for which they are intended. In order that rubber shall vulcanize, it is necessary to mix with it a certain proportion of sulphur, vulcanizing, or curing, as it is sometimes called, being merely the changing of a physical mixture of rubber and sulphur into a chemical compound of these ingredients, by the application of heat. Besides sulphur, some of the more important ingredients used in compounding rubber are:

Zinc oxide.--This toughens the rubber and increases its wearing properties and tensile strength.

Barium sulphate.--This stiffens the rubber and adds weight, so reducing the cost.

Lithopones.--This whitens the stock and makes it soft, and is used extensively in druggists’ sundries.

Antimony sulphide.--This makes the stock red and is a preservative against oxidation.