In the rear half of the camera are two boxes. The top one holds the unexposed roll of negative, while the exposed film is rolled in the bottom one. Roughly speaking, the film unwinds from the top spool, passes out of the containing box through a slit, over a set of sprockets into the "film gate," down past the lens and shutter, where it is exposed over a lower set of sprockets, and through a slit into the lower containing box, where it is wound on a spool.

"In the first place our cinematography is just still photography at high speed. We have to take approximately sixteen snapshots a second, so you can see that it takes a perfect machine to move the film along fast enough so that we can get sixteen good, clear, sharp pictures only slightly bigger than a postage stamp, on our film between the ticks of your watch.

"Now if you look through the little hole at the back of the camera you will see that the scene in front of us is in the proper focus, and if you look at the little ground glass finder at the side here you will see it just the same way, except that it will be upside down. Now I will close the telescope focus at the rear so that when the film is brought down before the lens it will not be light struck."

The "threading" of the camera then began. "This little flap sticking out of this slit in the top box," continued the cinematographer, "is the end of the film, which is tightly wound up in its holder. You notice that I draw it out and thread it between these rollers, making sure that the teeth of the sprockets enter the perforations along the sides of the film. I also make sure that the sensitized side of the film is turned out, so that the light coming through the lens will strike it first. After the negative has been led over the sprockets you notice that it is allowed to make a loop of a couple of inches of slack. Then it is led into the important device we call the 'film gate.'

"You see the gate is hinged and that these little claws or fingers running in grooves take hold of the perforations. The next thing is to close the hinged gate so that the film is tightly held against the aperture, through which the light strikes it and makes the picture. Below the gate we let the negative make another loop and then thread it over another system of rollers and sprockets and so to the slit in the lower box, where the exposed negative is rolled.

"The camera is now loaded and threaded and when I give the crank by which the wheels are turned a few trial turns you can see the way the mechanism works. In the first place you must understand that the film has to be jerked down with an intermittent motion. Don't forget to look for the intermittent motion, because, after the persistence of vision, that jump and stop, jump and stop, is the most important thing in cinematography—intermittent motion!

"You can see as the crank turns that the sprockets pull the film out and guide it along its course, and the little fingers jerk it down the space of one picture, or three quarters of an inch, at each jump. When the fingers are jerking the negative down, the shutter must be closed, and when the fingers are making their back trip to take a new hold on another length of film the strip must be as still as the Washington Monument, for the shutter to open, let in the light and transfer the image before the lens to the negative."

The photographer turned his crank and all the wheels in the camera began to move. The sprockets working in the perforations pulled out the film and made the loop larger. The little fingers entered the perforations and jerked the film down, taking up some of the slack of the loop. The reason that the loop is formed is to prevent the film being torn by a hard jerk by the fingers when it is taut.

"Now if your eye were quick enough—which it is not"—said the photographer, "and you could see behind the gate, you would see a movement like the following repeated sixteen times to the second: Crank turns, top sprocket adds three quarters of an inch to the top loop, bottom sprocket takes up three quarters of an inch of bottom slack loop, fingers spring from groove and carry film down three quarters of an inch, inconceivably short pause while shutter opens and picture is taken; during this pause, while film is stationary, fingers jump back into groove, slide back to starting point without touching film and shutter closes. The shutter is a revolving disk between the lens and film, and the holes in the disk passing the negative admit the light."

After a roll of negative film has been exposed it is sent to the studio dark room for development. Every precaution is taken, of course, that no ray of light other than that which comes from the ruby lamp shall enter this room where films representing hundreds, and perhaps thousands, of dollars are being developed. The actual process for developing is no different from that used in developing other films, but the difficulties in handling a delicate snakelike, strip some 300 or 400 feet long and 1-3/8 inches wide are tremendous. All amateur photographers appreciate the difficulties of developing in one string a roll of twelve films of a reasonable size, but think of handling a roll of film several hundred feet long no wider than a ribbon, and holding sixteen pictures to each foot of surface!

The difficulties of scratching, tangling, etc., were overcome by systematizing the process. In some cinematograph dark rooms the films are wound on racks about four by five feet, and then plunged into the various baths, which are in vertical tanks of convenient size. In yet other dark rooms the films are wound upon drums about four feet in diameter and revolved in horizontal tanks, only the lower part being immersed. The only difference is that the racks can be manipulated easier than the drums.

While in the motion-picture dark room the boy visitor asked the photographer in charge whether an amateur could step in and develop a few hundred feet of film granted that he had the necessary materials.

"Of course he could," came a cheerful voice from the darkness. "It's just the same as developing a roll of ordinary films, only we do more in a bunch than the amateur. If you'll step over here and watch this reel that we are now putting into the developing bath you'll see that it does just the same as the single film developed in the amateur's dark room." After watching this trained photographer and his assistant for a few minutes, however, the newcomer decided that it was not an amateur's job, but rather one of the most delicate operations in all cinematography, for the developer can remedy many faults of exposure by bringing out an under-exposed film or toning down an over-exposed one.

Leaving the dark room the next stage of the negative is the drying room, where the film still on the rack is hung up to dry. This drying is a very difficult process because there is great danger of the film either becoming too brittle and cracking or of its being not hard enough. The air in the drying room has to be kept at a certain even temperature and it must be filtered so that no dust or impurity can injure the film.

After it has been properly dried the film again is wound upon a metal spool, put in an airtight box and sent to the assembling room, where the various scenes that go to make up the picture play, taken at different times and on different rolls of negative, are joined together in their proper order to make a complete play in a single roll about one thousand feet long.

After the negative film is developed, dried and wound upon a metal spool it is sent to the printing room, where positive prints are made from the original impression. Right here it may be well to say that on a negative film or plate in any kind of photography white appears black and black appears white—hence the name negative. The paper or film upon which the print is to be made turns black wherever the light strikes it, so that when the negative is laid over the positive and exposed to a strong light the rays quickly penetrate the white spots on the negative and turn the corresponding spots on the positive black. The light does not penetrate the places on the negative which are black, and consequently leaves those places on the positive white. The result is that the positive shows the image just as it appears to the eye.

The principle of printing positive films, then, is the same as the principle of making photographic prints or positives from ordinary still photography plates or films, but of course it is far more complicated because of the mechanical difficulties of bringing the two long, unwieldy strips of film together in the proper position. The whole process is carried out by a machine which takes the place of the printing frame into which the amateur so easily puts the still-life photographic plate and printing paper.

There are several motion-picture printing machines in use in this country, but in their central idea they are similar, as they all pass the negative and positive films before a very bright light so that the impressions on the negative are transferred to the positive. The invention of this machine was a necessity for the commercial success of motion pictures, for obviously it was impossible to lay a strip of film several hundred feet long and about an inch wide in a printing frame over a positive film of the same length and width.

The spool of negative film is slipped on to a spindle so that it can unwind easily, and immediately underneath it the roll of unexposed positive film, properly perforated along the edges in exactly the same way that the negative film is perforated, is suspended on a similar spindle. Of course the only light in the printing room is the photographer's ruby lamp.

The two films unwind and pass downward, with the sensitive surfaces to the inside, and the positive on the outside of the negative. They are drawn together, and with the positive stretched flatly over the negative they pass over a pair of smooth rollers and toothed sprockets which enter the perforations of the two films with mathematical accuracy. They then make a small loop and enter a side hinged gate which holds them tightly against the printing aperture. This aperture is a hole just the size and shape of each picture on the film, and through it shines a very bright light which casts its direct rays upon the negative and imprints the image of the negative film upon the sensitized surface of the positive film. After passing the printing aperture, the two films make another small loop, run down to another toothed sprocket wheel and roller, and then separate, the printed positive being rolled upon one spool and the negative upon its spool below.

The action of this machine is very similar to that of the motion-picture camera, for like the device for taking the photographs, the movement must be intermittent in order to obtain good results.

If the operator desires to see whether the two films are in exactly the right position and everything is going smoothly, he can, by the use of a lever in the printing gate, drop a little red screen between the light and the films, and by looking through the hole see through the unprinted positive, and the developed negative, to the light inside.

After a roll of positive has been printed, it is developed by just about the same process as is used in bringing out the images on the negative film. Then, after it is dried, the various scenes are joined together, titles and sub-titles put in, any final editing that is necesary is done, and the positive film is ready to be put on the projection machine for the first trial.

The preparation of the titles, sub-titles, and other explanatory writings that are thrown on the screen in the course of a cinematograph play is a comparatively simple matter. The words are written or printed out in large letters on cards and photographed by a camera with a slower movement than the ones used for recording moving figures. The positives are made from the negatives so taken, in the same way that positives of other films are made, and after development and drying are ready to be joined to the film in the proper places.

Every firm engaged in the fascinating business of making and reproducing cinematographic plays gives the most careful and painstaking attention to the first "performance" of a film. Of course it is held in private before only the officials and a few critics invited for the exercise of their judgment. The event amounts to the same thing as the dress rehearsal of a play to be reproduced upon the stage, and any changes that are necessary in the judgment of the critics cause just about as much trouble. Any one of a hundred things may be wrong. Some little incongruous detail in the scenery may be noticed, some jarring gesture by an actor or a scene in which the action does not proceed fast enough.

If the officials of the firm decide that a film is below their standard, parts must be cut out, and new parts photographed over again until the whole thing suits requirements. Sometimes one scene must be done over many times before it suits exactly, and several hundred feet of film wasted. At a cost of about three cents a foot, it is plain that the waste in film alone is great, but when a big scene with a hundred or so actors in it has to be done over again, the cost of assembling the company, paying their salaries and other expenses is enormous.

Finally, when the officials themselves are satisfied with a film it is thrown on the screen for the board of censors in the various cities, and if it measures up to standard, and contains no objectionable features, it is ready for public reproduction.

When all this is done, the printing machine again comes into play, and as many prints of the negative as are needed are struck off, for in cinematography, as in still photography, it is a simple matter to run off as many prints as are desired, once a good negative is made. These prints then are sent out to as many theatres, in as many different cities, as desire them, and released for public view on the same day in every theatre in the country.

Having looked at the motion-picture camera, and at the complicated process for developing and printing the films, we are now ready to climb into the little fireproof box from which comes the beam of light that throws the pictures on the screen. This is the projector and it is probably the most complicated of all the machines used in cinematography. As it was a development through the application of well-known mechanical principles we will not go into this subject more deeply than merely to understand its central principle, which is intermittent motion.

The result toward which the inventors worked was a magic lantern such as was familiar to every boy ten years ago, that would throw upon the screen the tiny consecutive pictures on the film, with such speed, and at the same time so clearly and steadily, that the effect would be that of figures in motion. Most boys will remember the flickering, flashing and jumping that used to be noticeable in motion pictures, and many are probably aware that it was the improvement of the projecting machine that did away with these objectionable features.

The essential parts of the projecting machine are the lantern with its light and lens, and the device for running the positive film before the light with the proper intermittent motion. It might be said generally that the projecting machine looks like a magic lantern, but on close examination it will be seen to be an extremely complicated affair.

The powerful electric light, usually an arc light, which is placed in a metal box a few inches behind the rest of the projector, directs its rays through the glass condensers, thence through the film, and thence through the lens, which throws the image upon the white screen or curtain. The condensers are made of two carefully ground glass parts. The first is dish shaped, with the concave side turned in toward the light and the convex side turned outward. Immediately against it is another condenser the same diameter and convex on both sides so that the collected rays from the dished part are shot forward to a point where they will all converge. This point is the centre of the lens. From the lens the rays of light are projected in a widening beam to the white screen on which the pictures appear.

The film is passed before the beam of light at a point between the condensers and the lens, so that the image is projected through the lens. The film is run before the light with the figures upside down, like in the ordinary stereopticon, and the lens turns the image right side up again.

The most interesting part of the solution of the problem is the advantage taken of the persistence of vision. Photographed at the rapid rate of sixteen a second, and thrown upon the screen at the same rate of sixteen a second, it is plain that the stage of motion shown in the pictures every sixteenth of a second is reproduced. With the inability of the eye to tell that the screen is merely exhibiting separate photographs, the appearance is of motion. In most persons this visual persistence is only about one twenty-fourth of a second, but that is long enough to allow animated photography to be a pleasing illusion to them, for it gives the shutter of the projector time to hide one picture while the mechanism moves the film down to the next picture, bring the film to a dead stop, and let the shutter open again to reveal the next stage of animation.

The manner in which modern mechanical skill took advantage of this physiological defect, proved many years ago by the leading scientists, is nearly as interesting as this slight defect in nature's own camera—the eye.

Above the film gate is a metal fireproof box (many of them are lined with asbestos) in which is the roll of unprojected positive film. Below it is another similar box in which the film that has been shown is wound. The motion, which is directed either by a crank turned by hand or by electrical power, is the same speed, and practically the same in detail, as that of the film in the cinematograph camera. From the film box the film runs to a roller, where a sprocket enters the all-important perforations and draws out the strip to make a small loop above the film gate.

The shutter is placed in front of the lens. It is made up of a black metal circular disk, with either two or three open spaces, and a similar number of solid or opaque spaces. In general it looks like a very wide flat aeroplane propeller. Like the movement of the camera, the film is stationary while the shutter is open, and when the shutter is closed the film is jerked down three fourths of an inch, or the length of one picture, and brought to a dead stop by the time the shutter revolves and is open again. This is repeated sixteen times every second, so the film is cast upon the screen for one thirty-second part of a second, and the screen is blank one thirty-second part of a second while the shutter is closed and, as we might say, the scenes are being changed for the next act. Although the movement is just the same as in the camera, it may be well for the sake of making the thing perfectly clear to go through the motion very slowly.

For the sake of keeping out of fractions entirely too small for our consideration we have assumed that in both camera and projecting machine the shutter is open one thirty-second part of a second and then closed one thirty-second part of a second, the whole operation taking one sixteenth of a second. As a matter of fact the effort of the experts in animated photography is to have the shutter of the camera open for just as brief a space of time as possible, and on the other hand it is their effort to have the shutter of the projecting machine open just as long a space of time as possible, and closed as short a time as possible. In other words, they desire to shorten the time when there is nothing on the screen, and lengthen the time for the eye to photograph each image on the brain. By using a little different mechanism in the film gate of the projector this is accomplished to some extent, as well as obtaining a clearer, steadier picture than formerly was shown.

You will remember that in the camera and printing machine the film was jerked down by little teeth or fingers.

The simpler of the two methods in general use on projectors now is called the "dog" movement. It is composed of an eccentric wheel placed below the film gate, with a little roller projecting from it. The wheel revolves and once every sixteenth part of a second the roller is brought around so that it strikes the film and jerks it down the three fourths of an inch that makes the space of one picture.

The other method is known as the "Maltese Cross" movement. The name is taken from the fact that the chief sprocket wheel is shaped somewhat like a Maltese Cross. This wheel, with four notches in it, is attached to the sprocket below the film gate, and it is driven intermittently by a wheel with a pin that enters one of the notches on the Maltese Cross wheel at each revolution, and pushes it around the space of one quarter of a turn. This of course turns the lower toothed sprocket and jerks the film down the space of one picture. On the next revolution of the driving wheel the pin enters the next notch, turns the Maltese Cross wheel another quarter of a turn, and, by the motion imparted to the sprocket, jerks the film down another three quarters of an inch, thereby pulling another picture into place as the shutter opens.

Recent improvements on this movement have largely done away with the jar resulting from the pin catching the notches in the cross. The wheel that looks like a Maltese Cross has, instead of four notches, three grooves, dividing the wheel into three equal parts just as if a pie were cut into three equal parts but the knife stopped short, leaving a solid hub in the centre. The space between each groove represents the length of one picture on the film. Without going into a long, tiresome, technical explanation of this very important little feature of the projecting machine, it will suffice to say that the three-groove wheel is connected with the sprocket underneath the film gate. Near it is a revolving arm, and upon this arm is a horizontal bar. When the arm makes a revolution, and reaches a point where it touches the three-divided wheel, the mechanical adjustment is so fine that the horizontal bar enters the groove, and the revolution of the arm carries the three-divided wheel around one third of a revolution—or the space from one groove to another—turns the sprocket and pulls the film down the space of one picture, with a quick steady pull. After getting this far, the arm on its upward course leaves the three-divided wheel, which stands still while the shutter is open until the arm gets around again, and as the shutter closes pulls the sprocket around another space.

The strong light concentrated upon the film, in just the same way that you concentrate the sun's rays upon your hand with a burning glass, is very apt to set the film afire, particularly if through any slip in the machinery it stops in its rapid progress of about a foot a second. As machinery is not infallible, the manufacturers have invented various safety devices for protecting the film in case the machinery stops. Of course this is not necessary when non-inflammable film is used.

PERILOUS AND EXCITING TIMES IN OBTAINING MOTION PICTURES.—HOW THE MACHINE CAME TO BE INVENTED, AND THE NEWEST DEVELOPMENTS IN CINEMATOGRAPHY

WITH a clear understanding of the mechanism of the various motion-picture machines in mind, we are free to go on with the scientist and our young friend to the exciting times experienced by actors and photographers in making the pictures that delight people all over the world. First, however, let us briefly look back over the history of the art, for there is nothing more interesting than to follow up the experiments upon which Thomas A. Edison based his invention of the original cinematograph or kinetoscope.

Long ago, even before Edison was born, scientists tinkered with devices that would picture apparent motion, but they were rude attempts and little progress was made for many years. The first man to take a decisive step toward practical cinematography was Edward (or Eadweard) Muybridge, a photographer who lived in Oakland, Cal.; so he is rightly called the father of motion pictures.

Muybridge had been experimenting with snapshot cameras, as in those days instantaneous photography with wet plates was comparatively new, and, being something of an artist as well as a photographer, he decided that snapshot photographs of animals and men while running, jumping, and walking would greatly aid artists in transferring to their canvases the exact positions of the figures they wished to paint. In 1872 the people of California were considerably excited over the feat of Governor Leland Stanford's trotting horse Occident, which was the first racer west of the Rocky Mountains to make a mile in two minutes and twenty seconds, and the Governor was having him photographed on every occasion.

Governor Stanford also wagered that at one time during the trotter's stride all four feet were off the ground. Muybridge suggested his plan for photographing the animal's every movement, while running, trotting or walking, as a means of settling the bet, and the Governor, very much pleased, gave him free access to the stables and race course.

The photographer built a studio at the course and systematically went to work. First, he built a high fence along the track and had it painted white. Then he securely mounted twenty-four cameras side by side along the opposite side of the course and stretched thin silk threads from the shutter of each camera across the track about the height of the horse's knees. Occident was then led out and ridden along the course so that he would pass between the white background and twenty-four cameras. As he came to each silk thread his legs broke it and opened the shutter of the camera to which it was attached. Thus the animal photographed himself twenty-four times as he passed over the track and showed that Governor Stanford's contention regarding his movements was correct.

Laid in consecutive order in which the photographs were taken, each picture showed a different stage of the horse's movements, and if the series of photographs was held together and riffled over the thumb, so that each one would be visible for just the fraction of a second, the impression received, thanks to the persistence of vision, was that of a horse in motion. When Muybridge went to Paris the year after taking the photographs of Governor Stanford's horse he received a warm welcome from some of the greatest French painters of the day. He gave several exhibits of his photographs, but carried the work no farther.

Almost one hundred years before this, several brilliant Frenchmen were groping in the darkness for some way of showing motion by means of pictures, and brought forth a device known as the "Wheel of Life," or the Zoetrope. It was simply an enclosed cylinder, and upon the inner lower face, which was free to rotate, were placed a series of pictures showing the stages of some simple animation, in sequence, such as two children seesawing, or a child swinging. The upper surface was pierced with long, narrow slits, and when one looked through the slits, and the lower surface with the pictures on it was rotated, one actually saw only one picture at a time, but as they passed before the eyes the appearance was of motion. Various improvements on this idea were made, and silhouette paintings even were thrown on a screen so as to give an illusion of motion.

The development of photography was necessary, however, before motion pictures ever could be a success. About the time Muybridge took his pictures the old wet plate was superseded by the dry plate we know to-day, and scientists began the search for some material from which they could make film base.

Before the invention of films, motion pictures, as they were known at that time, were used chiefly by scientists in trying to analyze motion which cannot be traced by the human eye. Among the leaders in this work was the French scientist Dr. E. J. Marey, who studied the flight of birds and the movements of animals and men so carefully that he wrote a book entitled "Movement," which is still used by authorities in scientific research.

Doctor Marey set up another camera at the Physiological Station in Paris with which he and his associates made pictures of great scientific value. Those were the days of the early experiment with flying machines, as will be remembered from Chapter II, and the French inventors made careful studies of Marey's pictures of bird flight.

Doctor Marey's stationary camera was a simple bellows type which took an exceptionally wide plate. The shutter, which was operated by a crank, was a disk with slits in it, so that as it turned it intermittently admitted and shut off the light. Thus, as a white-clothed figure passed a dead-black background, in front of the camera, the various stages of its movements in the course of its trip from one side of the camera's focus to the other were faithfully recorded on the plate, each slit making an exposure of the image on a different section of the plate, showing the figure in a different position.

Many machines that were merely developments of the old zoetrope were brought out both in the United States and Europe, but the greatest obstacle to their success was that they were peep-hole machines of the kind that flourished in penny arcades a few years ago, rather than devices for throwing pictures on a screen so that a large number of persons could see at the same time. In general, these old-fashioned "moving-picture" machines were simply cabinets in which were mounted a series of transparencies made from pictures representing the stages of some simple animation. An electric light illuminated the transparencies and they were rotated so that one picture at a time was seen. In some of the more improved "wheels of life," such as were shown in this country, the transparencies in consecutive order were mounted on a hub like the spokes of a wheel and were rotated so that one was seen at a time, very much like the way Muybridge riffled his horse pictures over his thumb.

All this time two American inventors had been at work on the two most perplexing problems in animated photography at that time, and it was through their achievements that the first practical motion-picture machine was given to the world, just as it was through the achievements of the Wright brothers that the first practical aeroplane was given to the world.

These two men were Thomas A. Edison and George Eastman.

Mr. Edison had been working for several years on a motion-picture machine, but was handicapped by the lack of a practical film.

Mr. Eastman, after years of experiment, produced the film that made cinematography possible, in 1889.

With a strong transparent film, flexible, and compressible, to take the place of the clumsy glass plate, Edison was ready to go ahead with his work, started years before, and in 1893 the crowds at the World's Fair in Chicago saw the first motion-picture machine. It was called a Kinetoscope.

Simple as it was, thousands and thousands dropped nickels into a slot and peeped into the hole at the "moving pictures." Some of the boys who read this may remember machines like it. The mechanism was in a cabinet in which the pictures were shown on a positive film. This was about forty feet long and was strung backward and forward inside the cabinet on a series of spools in a continuous chain. The film passed before the peep-hole and the pictures were magnified by a lens. They were illuminated by an electric lamp behind them. A rotating shutter cut off the light intermittently, so that each picture was seen for the fraction of a second, and then a period of darkness ensued. The shutter was the only attempt at intermittent revealing of the pictures, for the film travelled continuously.

The camera that Edison invented for taking the pictures shown in his kinetoscope was in principle about the same as the one described earlier in this chapter, except that it has been wonderfully improved in mechanical accuracy and photographic clearness. The hardest problem facing him was the machine which would show the pictures to a large number of spectators at the same time and do away with the old peep-hole machine. The idea of the magic lantern immediately presented itself, but the inventor quickly saw the necessity of an intermittent motion, for if the ribbon of pictures was drawn before the beam of light fast enough to give the illusion of motion, each picture was thrown on the screen for such a short time that it was too faint to be seen easily. From this it was to Edison but a step to a practicable projector, and nothing remained but to improve its mechanical working.

Getting motion pictures is the adventurous part of the business, for this work requires operators and actors who are athletes and who do not know the meaning of fear. As pictures of scenery and events are taken in every corner of the world—in the jungles, in the arctic ice, on mountains and in deserts, the photographers all can tell absorbing stories of the strange places and things they have filmed.

In the rough the films are divided into four great general classes, with several special classes besides. They are scenic, industrial (showing the working of some great industry like steel making), topical, and dramatic. Scenic and industrial films are simply taken at an opportune time, as it is usually not necessary to make any advance arrangements, though the photographing may incur great risks.

Topical films, such as the pictures of the recent Durbar in India or some other great current event, are very valuable when quickly sent broadcast. Of course the photographer must have the same news instinct that the reporter has to get good topical films, for he must get there first and deliver his picture "story" to his studio "editors" as quickly as possible. The photographers often have hair-raising adventures in taking such films, as the single instance of the man who went up Mount Vesuvius during an eruption and took a cinematograph film of it will show.

The greatest variety of experiences, however, is to be found in the making of dramatic films—that is, motion-picture plays. As every boy knows, these stories have just as wide a range as the books in a library. There are plays based on biblical stories, and plays dealing with Wild West adventures; there are farces, comedies, and tragedies; in fact, there is no limit to the variety. These plays, however, can be divided roughly into two classes—that is, those that are produced on the motion-picture studio stage and those produced out of doors with the natural surroundings as the stage. The interesting things about either kind would fill a book the size of this.

In the early days of cinematography only simple shows were attempted, but now nothing is too big or too complicated or too expensive for the big concerns making pictures in the United States and Europe. The first motion-picture studio here was simply a portable, glass roofed, black walled shed set on a pivot in Edison's yard in Orange, N. J. It was called the Black Maria and makes an interesting contrast to the great glass studio at Bronx Park, N. Y., costing $100,000, in which many of the Edison films are now made. All well-equipped motion-picture studios these days are fitted out with space for several stages; a great tank for water scenes, carpenter shops, scene-painting studios, furniture and other stage properties to furnish scenes, costumes, stage fittings, and a great corps of photographers, mechanics, electricians, etc., besides the company of well-paid actors who take part in the shows.

If a play is to be reproduced in the studio, the architect draws the plans for the scenery, which are sent to the stage carpenters, who make the framework and stretch the canvas. The blank scenery is then sent to the racks, where the scene painters get to work on it.

In the meantime the property man at the studio, just like the property man at a theatre, has received a list of the things he will need to furnish the scene and give the actors the paraphernalia necessary for the carrying out of the play. He ransacks his storeroom and brings out tables, chairs, pictures, etc. The studio costumer also checks off her list and sees that she has in her great wardrobe costumes to dress the characters for their parts.

Meantime the stock company of actors is called together, the scenario, or plan of the play, is read, and rehearsals begin. All this part of it and the rehearsing are very much like the work preliminary to the staging of a regular play, except that the scenes are arranged, not according to the size of the stage, but according to the focus of the camera. Each scene is timed to the second so that the pantomime will tell the story but not tire the spectators with useless repetition. In rehearsing, the actors sometimes speak their lines—that is, the words the character would say—just as if they were to be heard, because it often helps them to give the proper effect.

Finally, when the stage director has one scene of a play down fine, after perhaps days or weeks of rehearsing, the photographer is called. He consults with the stage manager, measures off the distance for his focus, so that he will get all that is necessary into the picture, and nothing that is not wanted; and after seeing that every detail is attended to, the great battery of arc lights overhead is turned on, and the stage manager says, "GO!"

The photographer begins to turn his crank, keeping one eye on the stage and the other on his stop watch, and the stage director counts off the seconds, meanwhile shouting instruction to the actors on the stage. To an outsider the noises sound like a riot or a street fair rather than a theatrical performance timed to the fraction of a second in which the movement of an eye counts in the final effect. While the camera clicks off sixteen instantaneous snapshots to the second the stage director calls out the seconds, "One, two, three. One, two, three. Look out there, don't get out of focus! Keep toward the centre of the stage. Now, Jim, run in and grab the book agent—hurry, look angry! One, two, three. That's fine! Hey, there! shake your fist." And so it goes, until the director rings a bell or shouts, "That's all!" and the scene is ended. Just as the last pictures are being run off, a stage hand rushes into the scene and holds up a large placard with a big number on it. This number is the number of the scene in the play, and is watched by the men and women in the assembling room when they gather the various scenes of a picture play together and join them up in the proper order for one continuous roll. Of course in the joining the number is cut out of the picture for projection.

It very often happens that a stage director in his effort to get a graphic story reproduced on the film takes a great many more pictures than can be crowded within the limits set for the play. Then with the scenario in front of him, and a good magnifying glass to bring out the detail of the pictures, he takes his scissors, just as the editor takes his blue pencil, and begins cutting from the story the unnecessary pictures, just as the newspaper or magazine editor cuts useless paragraphs from the story or article. He must not cut out any picture that helps to tell the story, and yet he must sometimes cut out as much as 400 feet of film. He "kills" an unnecessary picture here, and an unnecessary picture there, and adds up their length until the story has been reduced to the proper size.

Although spectacles such as the one in the picture representing a battle on a bridge, and others even larger, are staged in the various big motion-picture studios, the most exciting work in the filming of motion-picture plays is out of doors where the natural surroundings make the stage. A great many of the shows seen to-day are taken this way, with real trees, real water, real mountains, or real streets affording the settings. Hence with studios in which battle scenes, riot scenes, water scenes, and practically any indoor scene can be reproduced; and also the great outdoors at the disposal of the cinematographer, there is practically no limit to the subjects that can be turned into dramatic films for the education and amusement of the public.

A few instances of the plays made out of doors will serve to show the limits to which the producers are willing to go to get new shows. The Edison company, with its big studio in New York and its manufacturing plant at West Orange, N. J., in the heart of the country where the Revolutionary War was fought, is reproducing a whole series of films of American history. These, so far as possible, are made on the exact spots where the dramatic events occurred. The first of the series entitled, "The Minute Men," was taken near Boston, where those historic defenders of liberty fought for their country. In this film is the famous scene representing the Battle of Concord, which was taken on practically the identical ground where the battle was fought. The producers spent a great deal of time in planning this series of pictures and so far as possible had every historical fact correct, so that the value of the series from the educational point of view is apparent. The other titles in the series will show how the scenes of the Revolutionary War were brought home to the American people. They included "The Capture of Fort Ticonderoga," "The Battle of Bunker Hill," "The Declaration of Independence," "The Death of Nathan Hale," "How Washington Crossed the Delaware," "Church and Country; an Episode of the Winter at Valley Forge," and so on. The film dealing with Washington's trip across the Delaware in the ice was made under conditions as nearly like those of the actual events as possible to get them. The pictures were taken during the coldest part of last winter (1912), and the photograph opposite page 193 was taken while the big scene was being acted out. This was taken in an arm of Pelham Bay, near New York, and the "scene shifters" had to work for hours in the bitter cold breaking up the ice and shifting around the great cakes in order to get the desired effect. Their success is attested by the picture reproduced here.

The Selig Company, with studios in Chicago and Los Angeles, and big stock companies of actors in both places also take some wonderful outdoor films. One of these was a play representing life in the African jungle, for which a special trainload of actors, and a whole menagerie of elephants, camels, lions, rhinos, leopards, pumas, zebras, and other animals, were shipped to Florida, where scenes much like those in Africa were found. This same company also sent a stock company and a corps of photographers to the Far North, where a film play was made amid the Arctic ice.

The Chicago studio of this concern is one of the wonders of cinematography, for not only has it a great building in which indoor plays are filmed, but a great land reserve for outdoor productions. In one place are artificial hills built in the natural forest, and upon them artificial feudal castles. In another are log cabins for frontier scenes, and in yet another a barren stretch for other kinds of scenes. The Los Angeles company is close to the mountains, the ocean, and the Great American Desert, so that it can furnish material for an endless amount of exciting Wild West shows.

One of the big films made in Europe was "The Fall of Troy," produced by the Itala Film Company, which reproduced the great wooden horse, the walls of Troy, and all other historical details. The great French, German, and English companies also have made big films.

In the production of plays built on well-known novels the motion-picture industry has found one of its most successful fields. Dickens's great novel, "A Tale of Two Cities," afforded the Vitagraph Company of America, one of its best films, while James Fennimore Cooper, Alexander Dumas, and even Shakespeare, and grand opera have been transferred to the cinematograph. From the great Biblical stories also have been taken films that have been shown by missionaries, and others interested in religious work, all over the world. The "Passion Play" was one of the first long films ever shown and it made a tremendous success.

Big spectacles are always popular and to fulfill the demand two locomotives have been run together at high speed, the motion-picture concern buying the machines outright for the purpose and leasing the railroad for a day; an automobile has been driven over the Palisades of the Hudson River, ships have been towed out into the ocean and blown up and whole towns of flimsy stage construction have been built only to be burned, while the motion-picture photographer recorded the whole thing on a film. One concern even got permission from the Los Angeles Fire department during a big fire, and dressing an actor as a fireman cinematographed him as he heroically rushed up a ladder amidst the flames and rescued a screaming woman from an upper window. The woman was an actress who had risked her life to go into the burning building and be rescued.

Of course the great motion-picture industry has not been without its fatal accidents. Several times actors playing the parts of men in difficulty in the water have actually been seized with cramps and have drowned before the eyes of the spectators. One time a picture was being taken of a band of train wreckers who were supposed to tie the switchman to the track. The train was supposed to stop just short of the man, but it actually ran over and killed him. The pictures were used at the inquest. During the filming of war pictures there have been explosions of gunpowder that were not intended, and in the taking of pictures of wild animals in their native haunts and in menageries, several photographers have been badly injured.

There is another big and important department in the filming of motion picture plays in trick photography. Every one who reads this has seen at the picture-theatre films of things that he knows perfectly well never could have happened—men walking on the ceiling, fairies the size of a match acting on a table beside a man, a saw going through a board, a piece of furniture assembling itself, a man run over by an automobile, his legs cut off, and then stuck on again all within a few minutes, marvellous railroad wrecks, and a thousand other things which could not happen or which the motion-picture photographer probably never could catch in his lens. All of these things are done through trick photography.

Double exposure, double printing, and the stop motion are the most common methods of obtaining these marvellous results. Opposite page 200 is a picture obtained during the reproduction by the Edison Company of Alexander Dumas's novel, "The Corsican Brothers." This film was obtained completely by the double exposure. In the story, the two brothers are twins so much alike that they cannot be told apart. They act exactly alike, and one even feels what, the other feels. In making the film the producers decided that it would be impossible to get two actors that looked enough alike to take the parts of the two brothers, so the same man acted both parts. In the picture referred to the brothers sitting at table with their mother are one and the same actor.

The picture was made by blocking off the whole left half side of the film with black paper and running it through the camera while the actor played the part of the brother on the right side of the table. He was timed to the fraction of a second, and when the exposed half of the film was blocked off with paper and the unexposed half run through, he acted out his part on the left side of the table, to this time schedule. So exact was his work that when the brother on one side of the table spilled a drop of hot coffee on his hand and started in pain, the brother on the other side, feeling the same pain as his counterpart, jumped at exactly the same second.

Another popular trick with the double exposure is a scene showing mermaids or divers swimming or walking at the bottom of the sea. First a large brilliantly lighted glass tank is set up in the studio, stocked with fish and sea life, and photographed. In this kind of a film the images of the real water are a little under exposed. Next a space the size of the tank is measured off on the floor with a gray scene laid flat. On the scene are painted faint lines to indicate water, and faint outlines of fish, seaweed, etc. Then the actress dressed for the part of a mermaid lies flat on the setting and goes through the graceful motions of swimming while the film upon which the real water pictures were taken, is run through the camera, which is placed above her with the lens pointing directly downward.

Another example of double exposure is seen in most films where Lilliputians or small fairies enter into the picture. The parts of both full-grown human beings and diminutive fairies are played alike by adult actors, but the difference in their size is obtained by taking each on the same film at different times. For instance, suppose a tiny fairy is supposed to appear to a grown man in the picture play. First the man goes through his act with the camera photographing him from a distance of about fifteen feet. Next the fairy goes through her act, bowing, etc., to the place where the man stood and is photographed on the film from a distance of say one hundred and fifty feet. The two impressions when printed give a lifelike effect of a full-grown man and a tiny sprite.

There are numberless films made by the stop-motion system, which simply means that the stage hands rush in and arrange things while the shutter is closed. All pictures in which you see a man or a woman falling off a roof or out of a window and subsequently getting up and running away are made by this system. The Edison film showing an automobile going over the Palisades and the driver being hurled to the rocks below was done with the stop motion. It is very simple. The cinematographer photographed the approach of the automobile and the human driver in the seat approaching the cliff at terrific speed. He stopped his camera, the automobile came to a stop, the automobilist got out and a dummy was placed in his seat. Then by starting the automobile a little back of where it was slowed down and stopped, and photographing, it the public could not tell that it had been stopped, and that the man in the seat who was hurled to the rocks below with the machine was a dummy.

A development of this is the picture-a-turn motion, which simply means that with each turn of the crank of the camera one exposure is made. By this trick many of the strangest films seen are made possible. The magic carpenter shop where saws and hammers move without human aid is an example. It is simply done by stage hands who rush on to the stage between each turn of the camera and advance the tools to one more stage of progress. The saw is at the top of the board, and the hammer is suspended in air (by invisible wires), etc. In the next picture, the saw is in different position, and the hammer has descended to the head of a nail. In this way all the magical effects of inanimate objects taking on life in the film are accomplished. One of the interesting details is the appearance of such objects as boards rising from the floor and placing themselves upon the bench ready for the saw. To do this the operator, keeping his shutter closed, advances his film a couple of feet and takes a picture of the board falling to the floor from the bench (pulled off by an invisible wire). As the film is moving backward, the picture when exhibited in sequence shows the board not falling but rising from the floor, and placing itself on the bench in a most mysterious manner.

Moving the film backward will give many strange results. For instance, in the plays where a little child is snatched from death under the wheels of an onrushing train just as the cow-catcher is upon her, it is no longer necessary to risk human lives before trains. First, the onrushing train is photographed with the film moving forward right up to the point where the child is to be standing when rescued. Then the train is allowed to run on past the point. It is then backed up at high speed, and the film run backward. When the locomotive rushes past the spot where the child is to be rescued her heroic rescuer simply dashes on to the tracks amid the dust of the receding train and places the child between the rails. When this section of film, which is taken backward, is fitted into the rest of the ribbon, and is run through the projector forward, it looks as if the rescuer rushed on to the track and grabbed the child out of the way as the train passed by.

Another popular trick by which fairies or ghosts are made to appear gradually in motion-picture scenes is the one by which the lens is narrowed down or opened up gradually. If a ghost is to appear, the hole through which the light strikes the lens is narrowed down so that only the brightest objects are photographed. The hole is gradually enlarged so that the light increases and brings out the figures plainer and plainer, until the ghost is in full view.

A great many good films, such as railroad wrecks, automobile journeys through the clouds, etc., are made with models, propelled by invisible strings over skilfully built scenery. The scene of figures walking on the ceiling is very simple inasmuch as it is only necessary to set the floor of the stage to represent a ceiling and take the pictures with the camera upside down. Men and animals can be made to run up the sides of buildings, simply by laying the scenery on the studio floor, and photographing the whole thing from above.