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Projecting machines are equipped with condensers by the manufacturers and are shipped with fixed distances between con- densers and motion head without reference to the focal length of the leqs to be used in the motion head, and the focal length of the condenser is not regulated to the length of the stereo or lantern- slide lens nor with reference to the focal length or position of the optical center of the motion-head lens, since neither is known at the factory, the size of screen and the length of throw from the project- ing station to the picture screen being unlsjiown. If the condenser lengths are inaccurate, the optical system as a whole may be cor- rected by determining the proper position of the lamp to bring the rays bent by the condensers to cross at the optical center of the lens, the optical center of the lens being previously determined by focusing a slide upon the screen. Adjustment fcr Slides or Motion Head. In a lantern having stereo lens and motion head, the distance from the condensers to the optical center of the stereo lens may be different (probably is different) from the distance between the condensers and the optical center of the motion-head lens. This condition requires that for good pictures the position of the lamp in the lamphouse must be changed each time the lamphouse is moved from motion head to stereo lens, or vice versd. The proper adjustment, when once learned, may be attained by noting the size and the shape of the s}X)t of light around the film window of the motion head, or upon the edges or light guard of the stereo lens. Emergency Projection. With reference to condensers, emergency projection means projection when there are no condensers available. A cracked condenser is serviceable as long as it holds together — it is better than hone. With the motion head, either or both condensers may be cracked, and the picture on the screen will not show it. AVith the lantern slide and the stereo lens, the back condenser will show its cracks less than the front condenser, but any crack in the front glass will show plainly upon the screen. It is when the condenser glass falls to pieces and drops out of the cell that the operator is required to ado])t emergency methods to save the show. 30 OPTICAL LANTERN 21 With one condenser gone, put the remaining condenser in the front position — the C-2 position of Fig. 21 — and move the lamp back in the lamphouse until the rays after passing through the condenser cross at the optical center of the lens; if the lamp cannot be moved so far, move it as far as possible. The picture upon the screen will be of tlie usual size, but of much less than usual brilliancy. If the edges are dim, and a longer lens is available, use the longer lens, thus reducing the size of the picture and increasing its brilliancy. In the nftotion head, the stereo lejis even may be moved to a position in front of the motion head and the regular motion-head lens removed, projecting the motion pictures through the stereo lens. The resulting picture upon the screen (taking the usual run of motion theaters) would be about four feet wide by three feet high, but bright, sharp, and distinct with the one condenser. Diffusion Projection. With both condensers lost, use ground glass instead — four sheets, two with the smooth sides together for the back condenser and two with the smooth sides together for the front condenser. They are diffusers rather than condensers, but they will give upon the screen a picture of full size but lacking in brilliancy if the usual objective lenses are retained. The longest available lenses should be used, sacrificing something in size and gaining something in brilliancy. Adjustment of the Optical System. Select the motion-head lens for foeal length according to the lens table, selecting it for the length of throw from the lens to the picture screen and for the size of picture desired upon the screen. Place a piece of film or a piece of scratched mica in the film window and focus it upon the screen. The lens being a double lens, ?. e.,alens tube having glasses at both ends, it may be taken that the optical center of the lens is at the center of the tube The length of focus of the front condenser glass, C-2 of Fig. 21, should be equal to the distance from the focal center of the motion- head lens to a point midway between the two condenser glasses. It may be less, rather than more. The length of the focus of the back condenser glass — C-1 of Fig. 21 — should be about six inches. A longer length of focus will reduce the breakage due to the heat of the lamp, while a shorter length of focus will give a brighter light upon the screen but probably 31 22 THE MOTION PICTURE with greater breakage, because the himp will be brought nearer to the glass. Push the lamphouse away from the motion head so that the cone of light will pass at the side of the motion head; then adjust the lamp until the cone of light "crosses" just at the side of the motion- head lens and opposite the focal center of the lens. The point where the cone of light crosses is the point where the solid beam of light coming from the condensers reaches its smallest diameter and then begins to spread toward the picture screen. As the lamp is moved forward in the lamphouse, this point of crossing moves forward away from the condensers and toward the picture screen. As the lamp is moved back in the lamphouse, the point of crossing is drawn back toward the condensers. Stop it opposite the focal center of the motion-head lens. Then draw the lamphouse back to the motion-head and notice the appearance of the circle of light about the film window. The appearance of the circle of light around the film window when the lamp ancl the optical system are in proper adjustment should be remembered by the operator as a standard. Before open- ing the film-window shutter to begin projection, the circle of light may be brought to that standard as nearly as the operator can remem- ber it and little or no adjustment Avill be required to improve the projected picture after the film window is opened. The optical system having been adjusted to the requirements of the motion head in preference to the requirements of the fixed slide and stereo lens, the process may be repeated for the stereo lens. Select the stereo lens for focal length according to the lens table, selecting for length of throw and size of picture desired. To produce a picture of comparative size, the length of the stereo lens will be about three times that of the motion-head lens. Place a slide in the carrier and focus the slide upon the screen. The lens being a double lens, it may be taken again that the optical center is at the center of the tube. Draw the lamphouse to one side and again adjust the lamp to cause the cone of light to cross at the center of the stereo lens. Notice the appearance of the circle of light, or of the cone of rays as it enters the stereo lens. This appearance may be remembered and will help in making a proper adjustment quickly for the projection of lantern slides. 82 OPTICAL LANTERN 23 The cone of light usually is visible in the room by reason of the dust motes floating in the air. If it is not visible for this cause, its formation may be studied and the point of crossing may be deter- mined by holding a white card in the cone of light and moving it toward and from the condenser until the circle of light upon the card is at its smallest, which will be the point of crossing. It is a great convenience in changing from motion-head to stereo lens if they can be so placed that readjustment of the lamp in the lamphouse will not be required. This can be accomplished by moving the motion head toward or from the lamphouse to bring the focal center of the motion-head lens opposite the focal center of the stereo lens. A lamp adjustment taken by many operators is that lamp posi- tion in which the circle of light upon the film window is reduced to the smallest circle possible which will fill the window. This results in a brighter picture upon the screen in spots, but the distribution ujion the screen may be irregular in intensity and objectionable coloring is likely. THE SLIDE CARRIER Just in front of the condensers is placed a frame for holding the picture slide. A part of the frame is made to slide, and is provided with windows and grooves for two picture slides. The movable part of the frame is arranged with stops at both ends of its travel so that it will stop with one or the other of its two picture slides in proper position for projection by the lamp and lenses upon the picture screen, the other picture slide being at that time out of the light of the lantern, waiting for the frame to be pushed across into its other position to bring the waiting slide into proper position for projection. The second slide being thus brought into the light of the lantern, the first slide is removed from the carrier and the third slide is put in its place. The carrier then is pushed back into its first position, showing the third slide upon the screen, and so on, the slides being placed in the carrier first at the right and then at the left, the carrier changing ends for each change of picture upon the picture screen. Simple Form of Carrier. The simple form of slide carrier is shown in the illustration of Fig. 22. The fixed frame comprises a track across the bottom and an open frame at the middle of the track. 33 24 THE MOTION PICTURE Within the frame is shown the shde carrier with its two windows, the carrier being shown shghtly out of center. The carrier has grooves open at the top into which the picture sUdes are shpped when they are to be projected. Some carriers have a single groove, four inches wide, admitting the American Fig. 22. Simple Slide Carrier standard size of slide, which is 31 X 4; in this type of slide carrier it is necessary to center carefully a foreign slide measuring only 3^ X 3^ that it may appear centered upon the screen when the slide carrier is pushed over. The picture of the American slide is the same size as that of the foreign slide, the additional area being blank margin. Carriers for American and Foreign Slides. Slide carriers for exhibiting both the American and the foreign sizes of slides may have a pair of centering springs which push either size to the center of the window, or may have two grooves — one wide for the American slide and one narrow for the foreign slide; in the latter case, in show- ing a mixed set of slides it is necessary to change the focus atljustinent of the stereo lens each time the slide changes from one groove to the other. Slide Window Masks. In Fig. 23 is shown a masked slide win- dow. No matter what the size of the slide placed in the carrier, only Fig. 23. Slide Holder Window Mask so much f)f its picture will be shown uj)on the picture screen as may be seen through the mask (shown as a black frame) in the slide window. 34 OPTICAL LANTERN 25 The slide-window mask is a boon to the operator who cannot make his lens cover his slide. Just put in a mask that the lens will cover. The average set of song slides will be more pleasing with the edges trimmed away by the sharp cut of the slide-window mask than with the corners trimmed away by fading first into color and then into darkness by reason of the failure of the lens to cover the field. Slide=Window Shutters. When the view upon the screen is changed merely by pushing the carrier across, the old view races off of the screen at a high speed and the new view races on. This is considered objectionable by some people, although it is a matter of opinion whether some of the cures are not worse than the malady. To cap the lens or to operate a small manual shutter or even a pedal shutter while moving the slide across is the simplest remedy. Devices are offered in connection with complicated slide carriers by which the slide window is closed by an automatic shutter except Fig. 24. Slip Slide Carrier when the carrier is in one or the other of its end positions. By push- ing the carrier across quickly, the interval of darkness caused by the shutter becomes very brief. The interval of darkness, no matter how brief, is objectionable, as the pupils of the eyes in the audience begin to expand and again must contract for the succeeding picture, repeating this at every change. Slip Slide Carrier. Li the slip slide carrier, shown in Fig. 24, the slide at the right is in the window for projection and the slide at the left is the new slide next to be projected. The lever and knob at the left engage the new slide and push it into a position in front of the slide already on the screen. Thus both slides are thrown upon the screen in confusion for an instant. The pawls of the con- trolling handle are released from the new slide when it reaches its position for projection and engage the old slide to withdraw it, so 35 26 THE MOTION PICTURE that by the return of the operating handle the old slide is withdrawn, leaving the new one in position in the beam of light. As the old slide is drawn from under the new one, a set of springs presses the new slide down into the position formerly occupied by the old slide, that is, into the position of proper focus for the lens. The change of slides can be made very quickly. A modification of this device carries an opaque shutter which closes the slide window as the new slide comes in and opens it as the old slide is drawn out, thus avoid- ing the confusion of projecting both slides at once. Mechanical Slide Changers. Mechanical changers take two forms, which may be classified as semi-automatic and full automatic. In the semi-automatic type of changer, the object desired is to have the view changed at the desired instant. This is of value in lectures, and in illustrated songs as well. Such a device consists of a spring for drawing the carrier across, with a lever for setting the spring to tension, and an electromagnet for releasing the carrier. The operator in the projection room places the new slide in the carrier and sets the spring to tension to draw the carrier across. When the lecturer desires to have the new slide projected he touches a push button or electric switch which releases the slide and the spring draws it across. The operator at the lantern then replaces the old slide with the next of the series, sets the spring to draw the carrier back, and again waits until the lecturer has released the carrier electrically. In the case of the illustrated song, the stage director, the orchestra leader, or the pianist would change the slides by the push button. For the dissolving lantern the operator changes the slide in the dead lantern and sets the dissolving shutter to tension. The con- trol exercised electrically by the lecturer or musician then releases the dissolving shutter to change quickly to its other position, making the quick shift from slide to sliae. In the full automatic changer, the slides are placed in a rack containing a space for each slide, and this rack or multiple carrier is stepped forward, step by step, either under control of the projec- tion operator, the stage director, or a musician in the orchestra. The rack for holding the slides in the full automatic changer takes the form of a wheel with the slides on the edge, a chain with the slides in the links, or of a nest of carriers in which slide after slide is brought into an operating position and then forced into position 36 OPTICAL LANTERN 27 in the beam of light for projection. Full automatic changers are much used in windows and in pubhc places for the projection of advertising slides, the changes being controlled by clockwork. Storage of Slides. Sets of song slides come packed in small wooden boxes, and between repetitions of the song they lie stacked upon the operator's table, lying close upon each other, with no oppor- tunity to lose the heat of the lamp acquired while being projected, and getting hotter every time the set is run through the lantern. Occasionally one or more are knocked from the table and the set is run a slide or two short there- after, either the operator or the theater manager paying for the breakage. A slide storage-box like that shown in Fig. 25, but preferably with the hinges taken from the lid so that the lid may be removed completely while operating but replaced when desired, will keep the slides in order, prevent accidental bceak- age, prevent the insertion of a slide in the carrier in reversed or inverted position, and give the slides a chance to cool between successive projections. The an- nouncement slides are kept in one end, the song slides in the other. The cost of one good slide or two cheap slides is about the price of such a box. DISSOLVING LANTERNS Up to the time of the introduction of the motion picture, the dissolving lantern was the most interesting of all optical illusions, and a favorite means of entertainment. It was developed to such refinement of detail that motion in projected pictures was well simu- lated in many instances. Entire scenes were played through with the very complete sets of lantern slides made and used with multiple lanterns, some sets of pictures requiring four or six lanterns working simultaneously upon the screen to produce the effects as planned. Triple Lantern. In Fig. 26 is reproduced an illustration taken from an old book upon the subject of the optical lantern. It shows Fig. 25. Slide Storage Box 37 28 THE MOTION PICTURE a triple lantern, three lanterns built in one, with tubes and dissolving valves at thje back for the oxv-hydrogen or lime light. It was with such lanterns as this that truly "dissolving" effects were produced. Imagine a rural scene, showing woodland, meadow, and lake. It is winter, and winter with a single lantern, winter with a single slide. By an auxiliary slide, in the same lantern, skaters appear Fig. 26. Triple Lantern for Dissolving Projection and glide over the surface of the little lake. The skaters pass off the side of the picture and the scene again is still, with a single lan- tern. Now the picture begins to darken; soon only patches of snow are left here and there. The view has been dissolved from the first lantern used to another lantern Avith a slide similar and register- ing exactly but with less snow. Two or three or more successive slides are dissolved each into the next of the set before the snow is entirely gone and the view remains in the neutral colors of March, 38 OPTICAL LANTERN 29 but with, yes, at first it seems elusive, but surely there is a suggestion of green in the meadow, positively now, and the darker green of the meadow is supplemented by a lighter green in the treetops. The branches begin to lose themselves in the mass of growing foliage, all in full color, and summer is here. How many slides have been used in the change is known only to the men behind the machines at the projection station; the audience, apparently, has seen but one lantern slide, but one view, in which not a tree nor house nor post of fence has moved, yet a view which has changed before their eyes in a manner even more wonderful than the changing of the modern motion picture, whose flicker betrays at once its mechanism and its origin. In the summer scene (from one lantern) the lake is no longer ice and a white swan (from a second lantern) glides upon its surface. Clouds begin to appear in the sky (dissolving the view from the first lantern into a third lantern while the second lantern holds the swans moving upon the lake). The swan disappears and lightning begins to flash (from the swan's lantern), the rain begins to fall (view from the third lantern, rain from the first lantern, lightning from the second lantern), the clouds move across the sky (mechanical attachment for the third lantern), and the storm rages, as with the modern motion- picture film, sheet-iron thunder, bean-bag rain, and wind drum, complete. The lightning ceases, lights appear in the windows of a house; presently the rain ceases and the clouds begin to break, and by and by the view dissolves into a moonlight scene with drifting clouds, ultimately giving a clear sky, moonlight sparkling on the surface of the lake, etc. A notable set of slides showed the burning of a building, the breaking out of the fire, the arrival of the fire brigade, etc. From this origin and from this field of activity comes the dis- solving lantern of the song slide set, where its duty now remains solely to shift from one slide to some other probably quite unlike it, the dissolving function of the lantern being operative merely to save the eye of the spectator from the shock of other methods of change. The Double Lantern. The modern dissolving lantern consists of two lamphouses, most conveniently mounted one above the other, although the arrangement of having them side by side has been 39 30 THE MOTION PICTURE tried. Each lamphouse is equipped with lamp, condenser, and lens system, slide carrier, and a shutter. The two shutters of the two lanterns are operated by a single handle and are so arranged that as the handle is moved one shutter is gradually closed and the Fipr. 27. Comliiiiation Projector, for Motion and Fixed Pictures, with Single Lantern other gradually opened. If in connection with a motion head, the lower lamphouse is arranged to slide for the stereo lens or for the motion head, the upper lamphouse being fixed in position. Slides are projected successively by placing the first slide in the lower carrier, the second in the uj)pcr. The first projection is made from the lower 40 OPTICAL LANTERN 31 lantern, the handle is shifted to change the shutters, the slide is changed in the lower lantern and the handle again is moved to change the shutters, when the slide in the upper carrier is changed. The slide carriers in such lanterns may be of simpler or more convenient form than in the single lantern. The pictures projected by the two dissolving lanterns should be of the same size and carefully lined up 28. Combination Projector, for Motion and Fixed Pictures, witli Double Dissolving Lantern together upon the screen. Modern single and double lanterns for motion head and dissolving slides are shown in Fig. 27 and Fig. 28. Lining Up the Double Lantern. In setting up the projecting lantern with motion head, care should be taken to bring the two pictures into approximately the same position upon the screen. 41 32 THE MOTION PICTURE although the pictures from the motion head and from the stereo lens will be of different shape and may be widely different in size unless the lenses are carefully matched. In setting up the dissolving lantern the two pictures from the lanterns should coincide just as accurately as it is possible for the operator to make them. Adjust- ment screws will be found on the upper lantern for this purpose. Alignment Masks. Considering the inaccuracy of slide masks in commercial sets of song slides, it is impossible to secure perfectly the desired result in dissolving without slide-window masks, such as shown in Fig. 23. With two such masks, cut from thin, ferrotype iron, or any thin sheet metal, of the same size and shape, and with two stereo lenses matched to exactly the same focal length (the lens makers will sell two matched lenses for an extra charge for match- ing), it is possible to dissolve without slides from one lantern to the other without showing any change in the edges of the white field of the screen. With this arrangement, good effects will be obtained with dissolving slides which are large enough to fill the windows. Dissolving Shutters. The dissolving shutters should be set to close each lens half when the lever is in the middle of its travel. The light should be cut off just in front of the lens, near the lens, preferably with a shutter having a saw-tooth edge operating from one side with a horizontal movement across to the other side. The shutters, having two wings which cut oif the edges of the lens first, leaving the middle of the lens effective until the last, and also the iris shutters which work between the lens glasses, inside the lens tube, and shut off the light beginning with the outer edges and gradually narrowing it down to a smaller opening in the middle of the lens until finally the light is stopped altogether, are fallacious in theory, for this reason: By such shutters, the volume of the light is reduced but the definition of the fainter image upon the screen is increased. With the shutter two-thirds over, the new image has twice the brilliancy, but the old image has greater definition — an objectionable feature. In the simpler cut-off working from one side only, the definition is impaired as the volume of light is dimin- ished and the vanisliing })icture fades away in a blur which the eye caiuiot follow, the eye acting to pick up the new picture as soon as that picture has the greater light volume, it having also from that time the greater sharpness of definition as well. 42 hi < B H X H 5' •J O H O ' X 0, CO O 0. X CO J? ►J s . !-< O Si & Q S T3 a a:S « c> O o CO OPTICAL LANTERN 33 Equipment of the Second Lantern. The second lantern, or upper lantern of the double lantern, should be complete and as far as pos- sible separate from the lower lantern. Positively it must have a rheostat separate from that of the motion-head lantern, with separate switch for opening its electric leads and separate wiring from the switch through the rheostat to the lamp. ' Obviously, the lower lantern may be called upon for use in the ordinary way for motion and fixed projection without dissolving, in case the upper lantern is out of order, or the supply of carbons runs short; it is advisable also to have the upper lantern complete for similar use alone, removing it from its higher position to the lower. The lower lantern should have the double-slide carrier which it would require if the upper lantern were not used. Operation of the Double Lantern. With electric lamps in the lanterns, the lamps are burned all the time of dissolving projection, since the striking and regulating of the arc requires too much time to be repeated for each new slide. During the projection of a roll of film with the motion head, the upper lantern may be cut out, striking the upper arc again while the lower lantern is projecting an announcement slide or a song title slide through its stereo lens. The upper lantern requires the same care as the lower, and its con- densers should be identical with those of the lower lantern, adjust- ing it to match the lower lantern in every way. With condensers of the same focal length, the lamp must be adjusted to give the same appearance of the circle of light upon the back of the stereo lens tube. The rheostat of the upper lantern must have the same resistance as that of the lower lantern, and should be of the same construction to have the same radiating capacity. The same class of carbons should be used for the two lanterns, and the carbons should be set at the same angle. Single=Lantern Dissolvers. If the perfect single-lantern dis- solver has been produced, it at least has not come into general use. The object of the single-lantern dissolver is to fade the picture screen from one picture to another in the manner in which the double lantern dissolves a view into a dissimilar one (no reference to the older art of dissolving), the result being accomplished with a single lamphouse. The slip slide carrier is a compromise effort in this direction. A promising dissolver for single lanterns is arranged as follows: 43 34 THE MOTION PICTURE The slide carrier is moved forward from the condensers until a separa- tion of about three inches is attained ; then a forty-five-degree mirror is mounted slidably between the condensers and the carrier to reflect the beam of light toward the ceiling, a second slide holder and second objective lens are arranged in the vertical beam of light, and a second mirror is arranged above the vertical objective lens to reflect the beam of light toward the picture screen. The first slide being projected by the lower or horizontal lens, the second slide is placed in the holder of the vertical system and the mirror is slid in to transfer the beam of light from the slide of the horizontal to the slide of the vertical lens system. Shutters are not required for the lenses. This gives the effect of changing pictures by moving a vertical line across the picture screen from side to side, the old picture disappearing before the line and the new picture appearing after the line. A modification is the substitution of a piece of polished clear plate glass for the mirror, leaving it always in its reflecting position when projecting lantern slides, whereby the light of the lamp is divided between the horizontal and the vertical lenses of the system. With this arrangement, a pair of dissolving shutters may be used and the fading of the entire view at once into the next view is obtained as with the double lantern. Precautions in Dissolving. With the electric arc as a lamp, and with both arcs burning all the time during the exliibition of a series of views, the only danger to the picture screen is the projec- tion of ludicrous combinations of two views, either successively shown or during the interval of superposition, when both are upon the screen together. Reversals. The slides must be put into the carriers right side up (which is "head down" in the carrier), for an inverted slide is just as comical in the dissolving lantern as anywhere else. A "re- versed" slide, however, may be rather more comical in a dissolving lantern than in a single lantern. By "reversed" slide is meant a slide which is put into the slide carrier "head down" but with the wrong side of the glass turned toward the lamp, reversing the picture on the scn^en right for left. With the same scene on two successive slides, probably with a change only in the position of the figures, as frequently occurs in song slide sets, dissolving one scene into the other with one of the slides reversed produces the crazy effect of a 44 OPllCAL LANTERN 35 prominent feature of the scenic setting disappearing from one side of the scene and appearing simidtaneously on the other side, every fixed detail of the scene changing places similarly, as though the scene were upon a revolving stage acting under control of some magician's wand. This is avoided easily by arranging the slides properly in their boxes before starting the series. Slide Alignment. Where two slides follow each other with the same scene setting, the slides apparently having been made from negatives made without changing the position of the camera, it is desirable to bring the two views into alignment so that the trees and the other fixed objects will not be "doubles" on the screen during the act of dissolving. Knowing this particular feature of the two successive slides, the dissolving shutter may be opened upon the second slide so slightly that the audience will not note the coming of the new picture, yet the operator may be able to note some par- ticular visible detail and bring the new picture into alignment with the old by moving the slide carrier of the new slide. Then proceed- ing with the dissolving shutter very slowly, the figures of the scene alone changing slowly and the fixed objects remaining upon the picture screen as though but one slide were being shown, the effect is delightful and well worth the effort required to attain it. It is a step toward bringing to life again the old art of the dissolving lantern. The operator who desires to attain this effect and who fortunately has a set of slides with two slides in it capable of the effect, always can secure the required alignment by gluing bits of paper, card, or match sticks to the top edge and to the side edge of one or the other of the slides, carefully bringing them into alignment upon the screen before showing the set before an audience. In this case, the slide arranged for the lower lantern in the preliminary alignment must be projected from that lantern when the effect is desired, for it is most unlikely that the two lanterns themselves will be so perfectly adjusted as to permit the slides to be projected interchangeably from the two carriers and get the proper alignment for dissolving in both cases. The utter extinction of the old art of the dissolving lantern is much regretted. Slide makers as well as lantern operators are to blame, the makers either forgetting the subject altogether, or taking for granted that the operators do not know how to dissolve. 45 30 THE IVIOTION PICTURE Many sets of song slides show a face in a flower, in a bouquet, or in a medallion, or some fixed setting equivalent to a frame. A slide showing the bouquet without the face, dissolved skillfully into a slide showing the bouquet or other device with the face, would please the audience. Just for the simple reason that it would please the audience, the theater manager would like to have it and the slide maker should offer it. Sets of slides (plebeian song slides) especially made for the dissolving lantern (and the skillful operator) should be offered by the slide manufacturers. The construction of such a dissolving set, by slides additional to the usual set, and made at the same time, and added to the set when used for the dissolving lan- tern, will add to the interest of the show and the reputation of the slide maker; let the theater manager demand them and the demand will be met by the manufacturers;. Speed of Change. The easiest method of control which the operator has in a set of slides is the speed at which he throws over the dissolving lever. This speed controls largely the dissolving effect upon the screen. By carefully watching the matter of lever speed, the change from the old slide to the new one in many instances may be made pleasing or ludicrous. Where the change between the two slides is in the figures only and the scene setting can be brought int® alignment, a very slow change produces a pretty effect. Where the change is from a scenic view to a single object in detail, as from a woodland scene to a bouquet, either with or without the usual framed face, the slow change is pleasing. Entirely dissimilar views sometimes unite in unexpected combinations which are pleasing and which may be offered to the audience by the slow movement of the change lever. Entirely dissimilar views sometimes unite in unexpected com- binations which are ludicrous in the extreme; two moons in one sky, or a white horse and buggy upon a parlor sofa, are not connnonly seen except upon the picture screen with a dissoh ing lantern and a thought- less operator. In a case of this kind, make a swift change by a quick movement of the dissolving lever, or change the order of the slides in the set. In a lecture, the order of the slides can not be changed. In an illustrated song, the slides sometimes are so characterless and so meaningless, that the rearrangement of a few of them, or the omission of a few of them, is (juite permissible. 46 OPTICAL LANTERN 37 THE MOTION=HEAD LANTERN The lantern is not different, but its method of operation has a requirement additional to that of a lantern used for fixed slide pro- jection only. The motion-picture film image being but one-tenth the area of the fixed slide, and the picture on the screen being re- quired to be about the same size, the motion-picture film must have ten times the intensity of light to stand the increased magnification. An increase in light intensity is effected by putting the film in a more condensed portion of the cone of light coming from the condensers, but it remains a fact that fixed slide projection may be accomplished satisfactorily with a less brilliant arc than that required for the motion picture. To state it the other way about, the motion-picture arc must be a hotter arc than that actually required for fixed slides, and the motion-head lantern must furnish a stronger light. Having the strong light for the motion picture, it is easy to use it for the fixed slides, and it is customary so to do. It is customary also to break announcement slides with the excessive and unnecessary heat. Take note that the motion-picture film is exposed to the heat of the arc for about one-fourteenth of one second, while the announcement slide is on the screen and exposed to the heat of the arc from ten seconds to a full minute or even more. The motion-head lantern equipped with an auxiliary rheostat, or' with an auxiliary' switch for an adjustable rheostat, will save money by using less electric current and will save money also by re- quiring fewer new announcement sliders to replace the slides broken by the unnecessary heat of the motion-head arc. With direct current, fifteen amperes is sufficient current for the projection of a fixed lantern slide upon a picture screen less than fifteen feet wide; for the same screen the motion-picture projection should use thirty to forty amperes. With only alternating current supplied from the power mains, the currents used by the lamp will be greater, rimning to sixty amperes for the motion-picture arc, but the proportion will remain. Auxiliary Rheostat. Two rheostats may be wired into the same lamp circuit, the first one of them as usual and the second one with a short-circuiting switch or shunting switch placed handy to the operator when standing at the projecting machine. The second 47 38 THE MOTION PICTURE rheostat being shorted by the switch, the first rheostat is adjusted to give the current required for the motion-head arc. The shorting switch then is opened and the second rheostat is adjusted (leaving the first as it was) so that the two together give a sufficient current for the projection of lantern slides, using probably not more than one-third and certainly not more than one-half the current required for the motion-head work. Thus adjusted, the motion head always is pan with the shorting suatch closed and the fixed slides always are projected with the shorting switch open. The arrangement of circuits with two rheostats is shown in circuit diagram in Fig. 29. At the extreme left are shown the street mains of the electric circuit, appearing as two vertical lines SM. Branch wires pass from the street mains to the lamp L at the right /^S ■AAAAA — /WWV ^JF 1 Fig. 29. Connections for a Single Lantern with Two Rheostats and in this pair of branch wires or lamp leads are included first the main switch MS and then the two rheostats R and AR, the auxiliary rheostat AR being provided with a shorting switch SS whose blades are connected to the terminals of the auxiliary^ rheostat. In operating, the switch SS is closed and the rheostat R is adjusted for the motion arc; then SS is opened and the second rheostat AR is adjusted to cut the current down for the song slides, fixed slides always being shown with the switch SS open. Auxiliary Rheostat for the Double Lantern. ^Mien the doul)le lantern is used for motion pictures and dissolving slides, it will be seen that the upper lantern never is used for the motion head. It will not require the adjustable-current feature. A wiring diagram for a double lantern for motion head and di.ssohdng slides, equipped with the current-saving rheostats, is shown in Fig. 30. At the left, Fig. 30, the vertical pair of lines represents the street mains for the electric-power circuit. From these street mains a 48 OPTICAL LANTERN 39 pair of wires is taken to two double-pole knife switches, one switch for each of the two lanterns. From the lower knife switch the circuit extends to the right to the lamp of the lower lantern, passing through the two rheostats R and AR, and the shorting switch is connected to the terminals of the auxiliary rheostat AR, as it was in Fig. 29. With the upper lantern, however, it is necessary to balance the current against the lower lantern when the shorting switch SS is open. To show that balancing in the diagram, two rheostats are shown in the circuit of the upper lamp, but the shorting switch is not required, as the upper lamp is used for slides only. A single \. ■MW^ — A/VW — I ^^ ^ ^^ I ^ ■WAA — A/W\A /? ^/r U^ 5v5 Fig. 30 Connections for a Dissolving Lantern with Two Rheostats rheostat will be sufficient for the upper lamp if it is capable of being adjusted to a resistance to balance the two rheostats of the lower lamp. Auxiliary Switch. Another arrangement for saving current and condensers and also for improving the quality of the exhibition, by reducing the heat of the lamp for slides, is that of using both parts of an adjustable rheostat in the sense of the two rheostats shown in Figs. 29 and 30. Fig. 31 shows an arrangement in a circuit diagram for a single lantern using two values of resistance from one adjustable rheostat, and Fig. 32 shows an arrangement of the same nature for the double or dissolving lantern when one of the lanterns is to be used for motion head also. In Fig. 31, the street mains are shown vertically at the left; from the street mains the lamp lead is taken to the knife switch on the power board, and from the knife switch through the adjustable 49 40 THE MOTION PICTURE rheostat to the lamphouse and lamp. The method of connecting the rheostat is the one usually used, carrying the circuit to the lamp- Fig. 31. Connections for an Adjustable Rheostat and Auxiliary Switch with a Single Lantern house through all of the wire of the rheostat and then short-circuiting as much of the rheostat wire as is not needed. The shorting may be done in the rheostat either by a movable handle, as indicated in Fig. 31, or by a short connecting wire between posts or terminals on the AAA /)[V\A/][W\/)f KKh ^1 VV\ U'VV J Vk ' /P ^ Fig. 32. Connections for an Adjustable Rheostat and .\u.xiliary Switch with a Dissolving Lantern rheostat. This method of connecting a rheostat has the advantage of giving a continuous circuit through all of the wires of the rheostat in case the short-circuiting arm of the device makes a defective con- 50 OPTICAL LANTERN 41 tact, or in case the short-circuiting bridging wire is accidentally broken or disturbed. Not only is the projecting possible in case of such an accident, but there is the further advantage that disastrous arcing will not occur at the rheostat because the break will be shunted by the rheostat wire. With this method of connection of the rheostat into the lamp circuit, either in the case of the arm type of device or of the bridging wire type, the short-circuiting conductor of the rheo- stat is cut and is taken by extension wires of sufficient size to carry the full current to the short-circuiting switch #S»S which is at the operator's hand as he stands at the j)r()jecting machine. By closing the shorting switch SS, the coils of the rheostat are short-circuited and the current has the full value intended for motion-head work according to the adjustment of the rheostat, but when the shorting switch SS is opened, then the rheostat has the short taken off of the coils which had been cut out, and the full resistance of the rheostat is effective upon the lamp circuit, cutting the current down to a proper amount suitable for use with slides without endangering them by excessive heat. The arrangement for the double lantern is shown in circuit diagram in Fig. 32. The lower lantern is equipped exactly as is the lantern shown in diagram in Fig. 31, but the upper lantern has the full resistance value of the rheostat always in its circuit, thereby equaling the adjustment of the lower lantern when the shorting switch is open, no switch being used with the upper lantern. Only two rheostats are required for the lanterns, and they should have the same resistance that they may balance each other for the song slides and other dissolving pictures. THE LENS The projecting lens should bo anastigmatic, rectilinear, and achromatic. It should reproduce upon the picture screen the image of the lantern slide with the least possible degree of distortion, or with a negligible amount of distortion of the picture. Lens Corrections. The usual lens for stereopticon projection is the Petzval type, an achromatic, rectilinear lens of four glasses, the two glasses of the front end of the lens tube being cemented to- gether and the two of the back end of the tube being held apart by a spacing ring. Fig. 33 shows the shape of the glasses used in this 61 42 THE MOTION PICTURE lens. The double end, with the two glasses and the spacing ring between, always should go next to the slide, and the single end toward the picture screen. With the Petzval lens, and with all astigmatic lenses of any type, it is impossible to get a sharp focus over all of the picture screen at the same time. The peculiarity of the focus of the astigmatic lens is that the picture sometimes presents streaks radiating from a com- mon point and at other times presents large arcs around a common point. The focus seems to be sharp only in a center spot or in a ring surrounding a center spot. In some slides the defects of the astigmatism of the lens can not be noticed, while in others it is promi- nent. Slides with sharp points of light show the defect more promi- NFGATMT \:\i\po5mve LSNS l£N3 '•■ Fig. 33. Section Through the Glasses of a Projecting Lens of the Petzval Type nently than slides having only lines, while slides showing scenes without sharply cut features near the edges will not show the astig- matism at ail. In any picture projected with the astigmatic lens the corners must be sacrificed to improve the central portion of the view, for the astigmatic lens usually is a cheap lens and lacks in angle of view as well as in the correction for astigmatism. An achromatic lens is one which will project white light without making color fringes along every sharp edge between light and shadow in the picture. White light is composed of many colored rays, and a single piece of glass, such as a glass prism, will separate the colors. The cheapest form of lens also will separate the colors, as may be seen with a cheap reading glass which colors the edges of black letters upon a white sheet. The projection lens must keep the lines clear of colors. Do not blame the lens for coloring which is due to the arc being out of adjustment. Coloring in the pictures caused by lack of adjustment of the arc will color the whites of the picture in blotches, while a poor lens will give a clear white in the 52 OPTICAL LANTERN 43 middle of a large white area but will color the edge where black meets white in a sharp Une, particularly toward the margins of the picture. A rectilinear lens is one which will project a straight line of the slide as a straight line in the picture on the screen. The straight line of the mask or edge of the picture of the slide is a line coming under this rule, and a rectilinear lens is required to give straight edges to the picture. Rectilinear lenses have their glasses separated into two groups, as shown in Fig. 33, for the Petzval form of lens, one group of glasses being mounted in the front end of the lens tube and the other in the back end, and each of the two groups having two glasses to give achromatic correction. The next consideration in the projection lens is the angle of the cone of light which it will handle. This requirement rises from the fact that the slide is not always placed centrally with the axis of the lens. Its manifestation on the picture screen usually takes the form of dark corners at the two lower corners of the picture. Wlien the axis of the lens is shifted to correct the corners, the sides of the picture become inclined toward each other, even with a rectilinear lens, and the "keystone" picture results. In addition to being achro- matic, rectilinear, and anastigmatic, therefore, the projection lens should have a sufficiently wide angle to bring up the corners of the picture without giving the picture the keystone shape to such an extent as to be objectionable. Even the cheapest lenses for pro- jection purposes are rectilinear and achromatic; anastigmatic and wide-angle lenses may be had if one wishes to pay for them. Lenses for Given Requirements. To select a lens for the pro- jection of lantern slides in a particular theater requires that the distance from the picture screen to the projection machine, called the "length of throw," be measured, and that note be taken of the offset distance of the projection machine, i. e., the distance to the side or toward the ceiling from the line of the center of the picture on the screen. If the distance from a horizontal line from the middle of the picture on the screen, measured from the lens to the line, is not greater than one foot for each ten feet of throw, it is likely that a good picture will be secured with a narrow angle lens. That is, for example, as follows: Wliere the screen is vertical, either upon a wall or on a drop curtain of a stage, the point of the middle of the picture prob- 53 44 THE :\I®TION PICTURE ably will be slightly above the middle of the screen, because the top of the picture will be thrown to the top of the screen, the bottom of the picture being above the bottom of the screen. With the projec- tion machine in the middle of the house at the rear, facing the screen, then the height of the middle of the picture on the screen may be com- pared with the height of the lens of the projection machine. Usually the lens of the projection machine is above the height of the middle of the picture on the screen. Now with a sixty-foot throw and the lens more than six feet higher than the middle of the picture, there will be a compromise between a sharp picture and a keystone picture unless a wide angle lens is obtained. With a throw of one hundred feet, the lens may be ten feet higher than the middle of the picture before the trouble becomes aggravated. With short throws from an elevated position in the room a very wide angle of lens shoukl be obtained if possible. The feature of the lens angle is illustrated in a diagram in connection with the focusing of the picture upon the screen. The requirement of greatest prominence, and sometimes the only requirement considered in selecting a lens, is the length of the lens focus. Length of Lens Focus. For the purposes of the projecting stereopticon, the length of focus of a lens may be defined as the distance from the center cf the lens tube to the lantern slide when the slide is in focus upon the screen; but the real focal length is just a little shorter, and the focal length is determined by the length of throw and the size of the picture required upon the screen, the lens being properly adjusted to the slide distance afterward. The focal length of a lens may be measured also by focusing the image of the sun upon a card and measuring from the middle of the lens to the card, or by focusing the light of a distant window upon a Vvhite card initil the lines of the window are sharp and then measuring the distance from the center of the lens tube to the card. The lens length recjuired for lantern slides for a given theater is most easily obtained from a lens table. Lens Table. Table T gives the size of the picture upon the screen for difi'erent lengths of lenses and different lengths of throw, when lantern slides are projected. At the left is given the lengths of the different lenses considered, from 5 inches to 24 inches. The columns at the right of the first column are arranged each for a 54 OPTICAL LANTERN 45 TABLE I Size of Screen Image When Lantern=Slides Are Projected Size of Mat Opening 2| by 3 Indies ■< U « OD ,* Length of Throw Pi< a (a a 1 S K fc, Z 0^^ C"" 15 20 25 30 35 ■40 45 50 GO 70 SO 90 100 3 ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. 5 8.0 8.8 10.8 11.8 13.5 14.8 16.3 17.8 19.0 20.8 5'j 7.3 7.9 9.8 10.7 12.3 13.4 14.8 16.1 17.3 18.8 19.8 21.6 G G.6 8.9 11.2 13.5 15.8 18.1 20.4 7.3 9.8 12.3 14.8 17.3 19.8 22.3 (5' G.l 8.2 10.4 12.5 14.G 16.7 18.8 6.7 9.0 11.3 13.6 15.9 18.2 20.5 ■" 5.7 7.6 9.6 11.6 13.5 15.5 17.5 19.4 6.2 8.3 10.5 12.6 14.8 16.9 19.0 21.2 "i 5.3 7.1 8.9 10.8 12.6 14.4 1G.3 18.1 5.S 7.8 9.8 11.8 13.8 15.8 17.8 19.8 8 6.6 8.4 19. 1 11.8 13.5 15.2 17.0 20.4 7.3 9.1 11.0 12.9 14.8 16.6 18.5 22.3 8h 6.2 7.9 9.5 11.1 12.7 14.3 16.0 19.2 6.8 8.6 10.3 12.1 13.9 15.6 17.4 20.9 9 5.9 7.4 8.9 10.5 12.0 13.5 15.1 18.1 21.1 6.4 8.1 9.8 11.4 13.1 14.8 16.4 19.8 23.1 '■»/ 5.6 7.0 8.5 9.9 11.4 12.8 14.2 17.1 20.0 6.1 7.6 9.2 10.8 12.4 14.0 15.5 18.7 21.9 10 5.3 . 6.6 8.0 9.4 10.8 12.2 13.5 16.3 19.0 21.8 5.8 7.3 8.8 10.3 11.8 13.3 14.8 17.8 20.8 23.8 12 5.5 6.6 7.8 8.9 10.1 11.2 13.5 15.8 18.1 20.4 G.O 7.3 8.5 9.8 11.0 12.3 .14.8 17.3 19.8 22.3 14 5.6 6.6 7.6 8.6 9.6 11.6 13.5 15.5 17.5 19.4 6.2 7.3 8.3 9.4 10.5 12.6 14.8 1G.9 19.0 21.2 IG 5.8 6.6 7.5 8.4 10.1 11.8 13.5 15.2 17.0 6.3 7.3 8.2 9.1 11.0 12.9 14. S 16.6 18.5 18 5.1 ».9 G.6 7.4 8.9 10.5 12.0 13.5 15.1 5.G G.4 7.3 8.1 9.8 11.4 13.1 14.8 16.4 20 5.3 6.0 6.6 8.0 9.4 10.8 12.2 13.5 5.S 6.5 7.3 8.8 10.3 11.8 13.3 14.8 22 5.4 6.0 7.3 8.5 9.8 11.0 12.3 5.9 6.6 7.9 9.3 10.7 12.0 13.4 24 5.5 6.0 6.6 7.3 7.8 8.5 8.9 9.8 10.1 11.0 11.2 12.3 55 46 THE MOTION PICTURE different length of throw, the length of throw being mentioned at the top of the column. With each length of lens there are two figures for each length of throw, viz, the height and the width of the picture upon the screen. This table works "both ways" in that it tells the size of picture when the lens length and the screen distance are known in advance, or it will tell the lens length required to give a picture of a desired size when the screen distance and the picture size are known. The f(jllowing examples show the use of the table : (1) With a house in which the screen is to be forty feet from the pro- jection machine, it is desired to project a lantern-slide picture about 9 feet sq&are. In the table, the column is taken which has "40 ft." at its top, being the sixth of the narrow columns, counting from the left, and in this column the pairs of figures are examined until a suitable pair is found; in this column there is a pair of figures, 8.9 and 9.8, and at the left, in the first column of the table is the figure, 12. The meaning is that a 12-inch lens with the 40-ft. throw of the theater will give a picture (from a lantern slide with a2|" X3" opening in the mask, the usual song-slide size), which will measure upon the screen a little less than 9 feet in height and very nearly 10 feet in width. (2) An operator is obliged to project lantern slides in a room where for convenience in placing his projector it must be 25 feet from the picture screen. He has three lenses for the lantern, 6-inch, 8-inch, and 10-inch. Which shall he use to get proper results at first trial, and not reveal a lack of skill and experience by making experiments before an audience? In the 25-foot column and opposite the figure 6 of the first column are found the figures, 11.2 and 12.3; in the same 25-ft. column and opposite the figure 8 in the first column are found the figures, 8.4 and 9.1; in the same 25-ft. column and opposite the figure 10 of the first column are found the figures, 6.6 and 7.3; the meaning is that the 6-inch lens will give a picture about 11 ft. X 12 ft.; the 8-inch lens will give a picture about 8 ft. X9 ft.; and the 10-inch lens will give a picture about 6 ft. X7 ft. The operator then measures or estimates the size of the screen and picks the lens which will give the largest picture that the screen will hold. (3) To change the size of the picture, the table may be worked both ways at once, as it were, taking the results by an inspection of the table by differences, since the olsject is to make a difference in the size of the picture now being projected by making a difference in the length of the lens used. With a 45-ft. throw and a 9-inch lens, the picture is too large. Going into the table to find the size of picture, it is found to be 14.8 ft. wide, or about 14 ft. 9^ in. Now taking the table to find the size of lens for a smaller picture, the 9J-inch lens gives a picture 14 ft. wide; thus, by the table, a difference of half an inch in the length of the lens makes a difference of dh inches in the width of the picture. By actual measurement on the screen, the projected picture with the old lens may be several inches different from the size given in the table, but the difference in the table for the difference in the lenses will hold good, and is the safest way to figure for a new lens. 56 OPTICAL LANTERN 47 To obtain the focal length of a lens accurately, put it in a photo- graphic camera and focus upon any object, say a strip of paper three inches long pasted upon a window pane, until the image on the ground glass is exactly the size of the object itself. Then the focal length of the lens is one-quarter of the distance from the ground glass to the object itself. Estimating Lens Length. In estimating the lens length to fill a given screen with a given throw, a margin should be left upon the screen all around the picture. Many lantern slide masks are not exactly centered wath reference to the position of the opening of the mask and the edges of the glass plates. ]\Iany slides, and particularly announcement slides, will exceed the usual standard limit of 2| X 3 inches, running even to 3 inches in height and 3^^ inches in width. A single slide which runs over the edge of the screen in an evening's exhibition will discredit the theater. It does'not create in the minds of the audience the proper thought that the slid* maker has been in error, that the slide is abnormal and too large for the screen, but creates instead the thought that the screen is too small for the slide or that the operator's skill is too small for his job, and that the theater is a small caliber place in general. Calculating Lens Data Without the Table. The rule used is the "rule of three" or the rule of simple proportion among four quantities; three being known, the fourth always may be found by simple arith- metic. For practical purposes, the rule may be taken, that the slide is to the 'picture as the focal length is to the throw. That is, the propor- tion between the size of the mask window in the slide and the picture as projected upon the screen is the same as the proportion between the focal length of the projecting lens and the distance of throw, lens to screen. To make this rule available for arithmetic, it is placed in the foj-ra Slide : Picture :: Focal length : Throw from which the equation is taken Focal length X Picture size = Slide size X Throw This equation works out for the height or width of the picture, according as the height or width of the slitle is taken. Taking any 57 ^8 THE MOTION PICTURE three of these measurements as known, the remaining measurement may be obtained, as follows: For Lens Length. Multiply together the slide size (say 3 inches wide) and the length of throw measured from the lens to the middle of the picture screen, taking both in inches. The result is to be divided by the width of picture which it is desired to project upon the screen, also taken in inches, and the final answer thus found will be the length of focus of the lens, in inches, which will be needed. All measurements must be reduced to inches before multiplying and dividing. In calculating for the projection of lantern slides upon a screen used also for motion pictures, it must be remembered that the shape of the lantern-slide picture is different from that of the motion picture; if the screen takes the shape of the motion picture, the lantern-slide picture cannot be made to fill it, and should be calculated for height, not for width. With a motion picture 9 ft. Xl2 ft., the lantern-slide picture will be 9 ft. X 10 ft. or 10 ft. X 1 1 ft. to secure the most pleasing effect in changing from one to the other quickly. Example. Calculating lens length. For a 30-ft. throw, it is desired to project a picture 10 ft. wide. 30 ft. is 360 inches and 10 ft. is 120 inches. The slide is 3 inches wide. 3X360 (sHde size multiphed by throw) gives 1080; then 1080 ^ 120 (the first result divided by the picture size desired) gives as an answer, 9, meaning that a lens of 9-inch focal length will give the desired size of picture at that throw. The picture will be slightly smaller, because the distance from the slide to the lens is slightly greater always than the actual focal length of the lens. The lens table gives the size of picture with a 9-inch lens at 30 ft. as 9.8 ft., or 9 ft. 95 in., or about 2k in. smaller than the simple arithmetical calculation. For Picture Size. INIultiply together the slide size in inches and the length of throw in inches, then divide by the focal length of the Ions in inches. The picture projected will be only a trifle smaller than the answer obtained. Ex.\Mi'LE. Calculating size of picture with any lens. With a throw of 35 ft. and a 10-in. lens, reduce the throw to inches, 420 inches, multiply by the width of the slide. 3 X 420 (slide size multiplied by throw in inches) gives 1260; then 1260 -^ 10 (the first result divided by the length of the lens in inches) gives 12 ft. in. Here the table gives 12.3 ft., or 12 ft. 3^ in. For Slide Size. It might seem that the operator would not have this calculation to make, since as an operator he would not 68 a -g OPTICAL LANTERN 49 have to make slides. It is involved in the making of emergency slides where the operator wishes to cut the mask with the largest opening which can be projected upon his screen. It is involved in the selection of announcement slides, which have mask windows of different sizes, many of them too large for the operator's picture screen. By this calculation, the operator may determine the largest slide-mask window which his screen will take with the lens he is using, aaid can select announcement slides which fall within the limiting dimensions. Multiply together the focal length of the lens and the size of the picture projected or which it is desired to project, in inches. Divide the result by the throw in inches. The final answer will be the dimension which in the slide window will fill the screen as de- sired when projected. If the width of picture has been taken in the calculation, the result will give the width of the slide-mask window. If height of the picture has been taken in the calculation, the result will give the height of the slide mask window. Example. Calculating slide-mask window. With a throw of 30 ft. and with a 10-in. lens, the screen is 8 ft. 9 in. by 10 ft. G in. By the table the 10-inch lens gives a picture 8 ft. by 8.8 ft., or 8 ft. by 8. ft. 9^ in. It is desired to fill the screen within a few inches, to project a picture, say, 8 ft. G in. by 10 ft. 3 in. For the width, 10X123 (the focal length of the lens in inches multiplied by the desired width of the picture in inches) gives 1230; 1230 -^ 360 (the first result divided by the throw in inches) gives 3i^3 as the final answer. The sliJe-mask window may be about 3J inches wide. For the height, 10 X 102 (the focal length of the lens in inches multiplied by the desired height of the picture in inches) gives 1020; 1020 -^ 3G0 (the first result divided by the throw in inches) gives 2' as the final answer. The slide mask may be about 2| by 3 J inches to fill the screen. For Length cf Throw. This calculation is required when the operator, having but one lens availalile, must determine how far from the screen to place his projection machine to secure a picture of the desired size. Aside from private exhibitions, in parlors or improvised halls, it has little value. Midtiphj the focal length of the lois by the desired picture size and divide by the slide size, talcing all dimensions in inches. The answer will be the distance in inches from projection machine to screen, or length of throw. 59 50 THE MOTION PICTURE Example. Calculation of length of throw. The operator has but a 6- inch lens, and the screen provided is 5 X 6 ft. Taking 5 ft. 6 in. as the widest picture safe for the size of screen, 6 X 66 (focal length in inches multiplied by picture wndth in inches) gives 396; 396 -^ 3 (first result divided by width of slide mask window in inches) gives 132 inches, or 11 feet as the length of throw. If an 8-inch lens were available, the calculation would give 8 X 66 ^ 3, equal to 14 ft. 8 in. as the length of throw. Such small dimensions as these, met only in private exhibitions, will not be found in any table, and when such dimensions are encountered the rule for calculation without the table becomes of use. Accurate Calculations. The distance from the lens to the lantern slide always is a little greater than the focal length of the lens. This difference has been omitted from the foregoing rules because the variation is small in the final results and within the variations of probable error in taking the measurements in the first place. For greater accuracy, the length of throw should be taken along the axis of the projection lens or of the optical .system. Let T equal this length of throw, lens to screen, F equal equivalent focal length of the lens, *S the slide-mask window dimension, and P the corre- sponding picture dimension, all dimensions being taken in inches or in the same unit. By the law of optics which may be called the "LaAV of the Rela- tion of Image Sizes," S : P :: D : T ST = PD (1) By the law of optics known as the "Law of Conjugate Foci," D-F : F : : F : T-F F- = {D-F){T-F) (2) These two equations include five variables, *S, P, D, T, and F, of which the value of the variable D never is recjuired in practice. Of the remaining four variables, S, P, T, and F, when any three of the four are taken as known or assumed or desired, the remain- ing one may be determined accurat-ely by the operations of simple algebra. As the final focus is obtained by shifting tJie position of the lens, and as the position of the lens depends upon its focal length, which 60 (I OPTICAL LANTERN 51 focal length has not been determined as yet at the time of measuring for the dimensions for the calculation, the only distance which can be measured along the axis of the optical system is the distance from the slide to the screen. Let H equal the distance from the slide to the screen, then, by the premises of the problem, D+T-==H (3) From the three equations (1), (2), and (3), any one of the four dimensions, S, P, II, and F, may be determined accurately, when the remaining three are known or assumed or desired. Lens Construction and Adjustments. Projection lenses are made up of a number of glasses, at least two, front and back, the focal length of each glass being greater than the resulting focal length of the combination. If still another glass were added to the combination, the focal length would be reduced as a result of the addition. Lenses of small curvature in clip-cap holders, similar to that shown in Fig. 34, may be used to change the size of pictures slightly and at a very small cost. The size of a picture may be decreased by ten per cent in this way, and by the use of a "negative lens" similarly mounted in a cap, the size of the picture may be increased slightly. Care of Lenses. Every day, wipe the out- side surface of the lenses with a soft camel's hair brush, without taking the lenses from the tube or the tube from the holder. The hair of the brush should be an inch long, without any stiff- ness whatever. The type of brush known as "camel's hair pencil," consisting of a bunch of camel's hair drawn into a quill, is suitable, a large size of pencil (yet smaller than a lead pencil) being chosen. In wiping the surface of ^^"- ^^ .^iHar^^f ^^°^' the lens, the brush should not be bent to rub the lens with the quill or handle, but to stroke the glass with the hair of the brush to sweep away dust grains or fine particles of lint which may have floated to the surface of the lens. Keep the brush in an envelope, such as is used for mailing letters, when not in use that it may not collect dust. The movement of the brush is to sweep away dust grains, not to polish the glass or clean it of finger marks. If the glass gets finger marks, more violent treat- 61 52 THE MOTION PICTURE ment, say with an extra soft chamois, is necessary to wipe them away; keep the chamois also in an envelope away from dust. "With time — and it is a matter of months- rather than of days — lenses will acquire a gray film upon their inside surfaces. This may be removed by washing with alcohol and Aviping with a dry, soft cotton rag, then polishing with soft chamois. The alcohol should be J alcohol and f water, as the pure alcohol will dry upon the sur- face of the lens so cjuickly that it will leave the surface as bad as be- fore. In taking out the lenses, lay them carefully and in order upon the table where you are worlcing, then take them up one only at a time, cleaning it carefully and putting it back in its proper position, so that there will be no possibility of a mix-up when they are put back in the tube. Once a year is often enough. FOCUSING The general subject of focusing is involved throughout the ad- justment of the Optical system of the lantern, and focusing the light has particularly to do with the adjustment of the lamp with reference Fig. 35. Diatrram of a Slide in Focus upon (he Picture Screen to the position of the arc relative to the condensers. The relation of the projected image to the screen upon which it is to be viewed now will be considered. The final focus is attained by moving the stereo lens slightly forward or backward in its holder to bring the converging rays of light into focus upon the picture screen. From each point of the lantern slide a bundle of rays passes to the lens, striking all over the back surface of the lens, being bent within the lens and passing out of it practically from all over the surface of the front glass; then the bundle begins to draw together and finally converges into practically 62 OPTICAL LANTERN 53 a single point, or very small spot of light. The distance of this spot from the lens is dependent upon the distance of the lens from the slide, and by proper adjustment of the position of the lens, the sharp focus of the bundle of rays may be made to occur upon the surface of the picture screen. This gives the condition illustrated in Fig. 35. The Fig. 3G. Diagram of a Slide Out of Focus Upon the Picture Screen. Lens too far from Slide lantern slide is at the left, the lens near it, and the picture screen is at the extreme right. The bundles of rays from the lens meet upon the screen surface. For illustration of the out-of-focus conditions, Fig, 36 is given, illustrating the condition when the lens is too far from the lantern slide, and Fig. 37 is given, illustrating the condition when the lens is too close to the slide. In Fig. 36, the converging bundles of rays leaving the lens cross before they get to the picture screen and spread again, reaching Fig. 37. Diagram of a Slide Out of Focus Upon the Picture Screen. Lens too close to Slide the screen slightly spread out, the different adjacent bundles blend- ing into each other and producing the blurred effect upon the screen well knowTi as a slide out of focus. The true focus of the image is at the dotted line drawn across the rays at the point of crossing of 63 54 THE MOTION PICTURE each of the bundles of light. This would be the proper position of focus for the lens if the screen were nearer, and the image is corre- spondingly smaller, in proportion to the lesser distance of the screen from the lens. This diagram shows clearly how the nearer screen or shorter "length of throw" gives a smaller picture upon the screen for the same lens, or same focal length of lens, as shown by the lens table. The "focal plane" or "image plane" represented at the dotted line of Fig. 36 may be moved forward toward the picture screen at the right of the figure by mo\'ing the lens back toward the lantern slide. In Fig. 37, the lens is shown moved too far toward the slide. The converging bundles of rays now do not meet before they reach the screen, nor even at the screen, so that the result is a blur in the projected image, as before; as a matter of fact the rays would meet far to the right of the diagram, producing a xery large picture upon a more distant screen. The best adjustment for focus is attained only by experimental adjustment, moving the lens forward until it is just a little too far, then moving it backward until it is just a little too near, then taking a position between. With a cheap lens, sharp focus may not be obtained all over the field of the picture screen at once, because of the feature of curvature of field, or cun^ature of the image surface. Curvature of Image. The surface, or the imaginary surface, upon which the image is brought into focus has been called, as quoted, the "focal plane" or "image plane" because it ought to be a plane or flat surface. To make it so, or even approximately so, requires specially constructed lenses for projection, involving usually a greater number of glasses in the lens tube and a correspondingly greater amount of labor and skill in manufacture and correspondingly higher prices to the purchaser of the lens. Curvature of the image is illustrated in diagram in Fig. 38; the slide is represented at SL with its surface flat, as it always is; the lens is sho^v^l at 0, and the image is shown at 7 in a curved line. This diagram represents a sectional view through the center of the slide, lens, and image, taking a vertical section by cutting the whole theater, as it were, into halves. The shape of the image at / is spher'crJ, or saucer-shaped, with the edges jf the saucer bending toward the projecting operator and the center of the saucer bent back toward the iniddk' (jf the picture screen. r 64 OPTICAL LANTERN 55 If the lens be adjusted to bring the bottom of the saucer-shaped image to the surface of the screen, there will be had a very sharp focus in the middle of the screen, with gradual fading away of detail toward the edges of the screen, the corners being worst of all. By bringing the lens slightly nearer the slide, the middle of the image or bottom of the saucer of the image is, theoretically, pushed back through the screen, giving a slight blur in the exact middle of the picture, surrounded by a broad band or ring of sharply focused image, then fading slightly again toward the corners. This is the best condition of focus where the effect of curvature is manifested in the lens. The condition of adjustment with the center of the picture Fig. 38. Diagram Showinrojection. Otiierwise, the wider angle is a needless expense. Inclined Screen. To reduce distortion in the, picture with a lens of narrow angle, the screen may be inclined slightly, as shown in Fig. 45. This brings the optical system back to the fundamental condition of Fig. 1 and of Fig. 35. The inclined screen is objection- able to the spectator because of the difference in distance from the eye to the top and to the bottom of the screen, and this difference will itself bring in the keystone effect to the spectator's vision, even though the picture upon the screen be perfectly rectilinear. Fia;. 44. Diagram of the Ec- centric Slide with a Wide- Angle Lens 70 OPTICAL LANTERN 61 All of the remedies for distortion may be used at once, inclining the screen a little, tipping the table a little, and setting the lens off center a little, including also the keystone mask. The Keystone Mask. The keystone effect of Fig. 40 may be compensated for, so far as the edges of the picture are concerned, by providing the slide holder with a keystone mask for the window through which the slide is projected, the edges of the mask being a little smaller than the mask of the slide. Measure the angle of inclination of the sides of the picture on the screen and make the sides of the mask have the same angle of inclination. The top and the bottom lines of the mask are parallel if the picture on the screen is true in that detail. The mask now is placed in the slide-carrier window with the narrow edge up; the lens magnifies the upper edge of the mask because of the greater distance to the picture screen, Fig. 45. Diagram Shov.ing the Inclined Picture Screen and the keystone mask throws a rectilinear field of light upon the screen. Two masks will be needed, one for each end of the slide carrier, or one for each lantern of a dissolver. A single mask for the fixed window of the slide holder would be too far out of focus to give good service. The keystone mask will not correct the distortion of the image itself, but only correct the margins of the projected picture. With lantern slides of varying sizes, only those larger than the keystone mask will be corrected, and those of course are corrected by the cutting off of a portion of the edge of the picture as seen in the mask window of the slide itself. With the motion head, where all images for projection are of uniform size, the keystone mask becomes more practical. Greater skill is required in fitting it, because of its smaller size. 71 62 THE MOTION PICTURE LANTERN SLIDES Announcement Slides. Commercial announcement slides very frequently are over-sized. In selecting them, care should be taken to avoid getting a slide which will project a picture or field larger than the screen. Emergency Slides. The quickest emergency slide is made of two cover glasses, a slip of draftsman's tracing paper or tracing linen, India ink, and a binding strip or piece of gummed paper. The mucilage edge of an envelope flap is always available for gummed paper when nothing else can be had. A lantern-slide mask or win- dow is desirable, but not necessary. Write with a fine pen upon the tracing paper or linen, place between the glasses, stick together with the gummed paper and put it into the lantern. If cover glasses are not at hand, the binding strip may be slit on a couple of song or announcement slides and the cover glasses thus obtained. This slide is improved by turning the tracing paper over and tracing the writing on both sides of the sheet before putting it into the cover glasses. Cover glasses, masks, and binding strips should be at hand at all times for the repair of slides. Add to this equipment a bottle of Higgins Waterproof Ink and a supply of crowquill pens and tracing paper and the emergency slide-making set is complete. Cut the tracing paper to lantern-slide size, place a mask upon each small sheet, and run a sharp pencil around the window of the mask, ^^^len writing, keep the words inside the pencil line and parallel to the edge of the sheet. For a typewritten slide with this outfit, cut a larger sheet of tracing paper, place a mask upon it, and nm a sharp pencil around inside and outside of the mask. Place this sheet in the typewriter with a carbon sheet back of it, the carbon surface against the back of the tracing paper. Write within the inner window line. When taken from the machine, the sheet will have the ink of the ribbon on one side and the carbon of the transfer paper on the back, giving a double density for projection. If the written matter is not cen- tered in the window, the mask may be adjusted over it, the pencil run around the outside of the mask, and the sheet trimmed to the new margin; then bind between cover glasses with gummed paper. 72 OPTICAL LANTERN 63 Unless skillful in making the Roman letters, the script form of writing will produce the more acceptable result, since mistakes in spelling and in form of letters are less likely to occur. Repair of Slides. The cracking of the glass of a lantern slide usually occurs in the cover glass, not in the photographic plate. Slit the binding strip around the edge, throw away the cover glass and substitute another which has been cleaned with alcohol and polished with a chamois or piece of newspaper; rebind with a new strip of gummed paper. If the photographic plate is broken, it is better not to attempt repair upon a rented slide. If you own the slide, it may be repaired as follows: Place the broken parts glass down ufon a cover glass and cement them to it and to each other unth Canada balsam thinned with a little turpentine, leaving them until well set. Then cover and bind; if too thick for the slide carrier, project without cover glass. 73 TWO SCENES FROM PHOTOPLAY, "HER MASTER' Courtesy of Sclig Polyscope Co., Inc., Chicago SCEITE FROM PHOTOPLAY, "THE FAIR DENTIST' Courtesy of Independent Moving Pictures Co., New York MOTION HEAD PART I PORTRAYAL OF MOTION Abstractly considered, apart from the means for projecting it and from the means for recording it, the motion picture is a picture in which motion is the prime feature. It is a picture so recorded that, itself a record of a moving thing or set of things, it, when properly viewed, will reproduce to the viewing person not only the outlines and details of the objects pictured but also the motion of the objects pictured. A running horse portrayed by a fixed picture, such as a lantern slide or fixed print, will show the outlines of the horse in full detail in the properly lighted portions of the animal and of the background; it even will suggest motion, by reason of the position in which the animal is portrayed, perhaps with two feet off the ground or even galloping with all four feet clear of the earth; but in such a picture the motion is only suggested by the attitude portrayed by the still picture. The motion picture must do more than merely suggest the motion of the subject photographed; it actually must show the motion so that there is no doubt in the spectator's mind that the object being exhibited is in motion, or was in motion at the time it was photographed. Yet the motion picture in itself is a dead, inert photograph. How, then, is motion portrayed in it? Go back to the thought of motion in the subject itself. In what way is motion manifested to the spectator viewing the sub- ject? The movement of the subject is known only by observing it twice arid noticing whether it ii or is not in the same place or position both times. If it is in the same place both times it is observed, then we say that the subject is still. If it is, upon a second look, in a position or location different from that of the first look, the ob- server says that the subject has moved. Now looking a third and fourth time, and noting that each time the subject is in a different Copyright, 1911, by American School of Correspondence. 75 2 THE MOTION PICTURE position from any of the other positions which it has held, the ob- server says that the subject is moving continuously, and if the dif- ferences are all the same, and if we have looked at regular intervals, the observer concludes that the subject is moving at a uniform rate. Looking at a thing several times to see whether it is moving is an act performed unconsciously. The eye cannot look at anything for less than one-fiftieth of a second, because of a peculiar property of the eye- called "persistence of vision," and when anything is seen in any position, it is seen for that length of time. If it is not looked at longer than that, the impression of motion is not given. Looking at it for half a second, it is seen successively in twenty-five different positions, or the equivalent, and when the observer looks at an ob- ject for half a second to see whether it is moving, and finds that it is moving, he really has looked several short looks joined each after another, and in each of the brief looks the object has been in a dif- ferent position from that of the preceding look; proof of motion thus has been received. Proof of Motion. Proof of motion is conclusive to the human mind when upon looking continuously at a physical object in nature it is observed to change its position. Proof of motion in the subject of a picture may be offered by the same means of making it apparent to the eye; that is, while the eye is looking continuously at the subject portrayed in the picture the subject is observed to change its position in the picture. A series of pictures may be made with a single camera, which, by close notice, will prove motion. Assume that an amateur photog- rapher with a hand camera is taking pictures as rapidly as his skilled hands will enable him, the subject being a parade passing down a city street. The camera worker is situated on one side of the street opposite a prominent building, of which the two corners and the central door may be seen in each picture made of the procession. When these pictures are developed and printed, it is noted that in one picture a carriage drawn by distinctive white horses is seen at the right of the picture, apparently entering the picture, judging from the attitude of the horses and the direction of their heads. This sug- gests motion, but does not prove it. Another picture, however, shows the horses half-way between the corner of the building and the central door; another picture shows the horses opposite the door 76 I MOTION HEAD 3 of the building, with the carriage still close behind; still another pic- ture shows the horses near the left of the picture, with the carriage close behind and the heads of the horses still toward the left. By comparing these pictures, the thoughtful observer will conclude, and correctly, that the horses and the carriage were moving while the series of pictures was being taken. These pictures, when taken together as a series, are pictures of motion and show motion if one studies to see it. The modern perfected motion picture is but the elaboration of this method of recording motion, and the projected motion picture is but a perfected method of viewing it. Perfected Motion Picture. The per- fected motion picture makes a series of pictures similar to the series of the proces- sion, but makes them so rapidly one after another, with such a short space of time between pictures, that the change or difference between pictures is very small, the motion being shown by increments from picture to picture. Take fur example the motion picture of Fig. 1 , which shows a harvesting machine or reaper cutting grain in the field. One part of such a machine is a large revolving flail, comprising a wheel-like formation of six or eight slats revolving: over the sickle or cutting bar to prevent the cut stalks of grain from falling forward and to control their fall backward over the sickle bar. This wheel of slats revolves rapidly as the reaper is driven across the field, cutting the grain. Note the picture for the motion of the slats. In the top picture, the slat next the top reaches to the driver's hat and is exactly in line with the brim of the hat. In the picture next to the top figure, taken only one-fourteenth of a second later in time, the slat is not seen at the brim of the driver's hat but noticeably above the brim, Fi! ;. I. Motion-Picture of Harvesting Machine in Operation 77 4 THE MOTION PICTURE and much nearer the top slat, for the top slat is descending. In the third picture, the slat being watched is as high as the top of the driver's hat and is higher than the slat, formerly the top slat and now going down. In the fourth picture of the series the slat being watched is slightly above the height of the driver's hat. In the fifth picture, taken about a quarter of a second after the first picture, the Fig. 2. Motion-Pictiu"e Portrait of a Lady slat being watched has reached nearly its full elevation at the top of the wheel, and the next slat has reached the height of the driver's shoulder. In the sixth and last picture of the series, the slat has moved from the driver's shoulder to the height of his chin. Also note the position of the driver. In the first picture, not all of his body is in the picture; in the second, it is all in the picture; in the third, there is a space between his body and the margin of the pic- ture; in the fourth, the space is wider; and in the fifth and sixth, the space between driver and edge of picture continues to widen. In Fig. 2, a motion picture is shown of circular form instead of strip film form. In this figure, it may be determined by studying 78 J MOTION HEAD the small pictures in sequence that the lady begins and ends the picture with a profile view, but turns her full face toward the camera during the progress of the picture, also she raises her hands to her head as though arranging her hair. In both Fig. 1 and Fig. 2, the differ- ence between any two consecutive pictures is so small that the pictures are alike except upon the closest inspection. In taking pictures of objects which are in motion at such speeds as the eye can follow easily, and where the desire is to reproduce the motion pretty much as it was seen by the eye when viewing the physical object, an interval of about one- fourteenth of a second is taken, the object being photographed at the end of each one-fourteenth second, as is the case with the harvesting machine. In the case of motions which are so slow that the eye with ordinary observation cannot notice the motion, a longer interval of time is con- veniently taken. A growing plant may be photographed once each day, and not oftener than once each hour unless it is desired to portray the opening of a single blossom; with these pictures taken at these comparatively long intervals, the change between successive pictures will be very small. In the case of motions which are so fast that the eye cannot follow the motion, a much shorter interval of time must be taken, in order that the change in the position of the moving object in successive pictures will be very small. The wings of an insect in flight move so rapidly that to the eye they are but a blur, and to Fig. 3. Motion Picture of an Insect, Made at High Speed 79 6 THE MOTION PICTURE photograph them in a manner that will reveal their proper motions for study requires that they be photographed at much shorter inter\'als than one-fourteenth of a second. Pictures of this class have been taken at the rate of two thousand pictures in one second. Fig. 3 shows such a picture, the subject being a dragon-fly in full flight. Motion pictures of bullets in flight have been taken at the rate of five thousand pictures in a single second. This is the motion picture — a picture which shows a record of the successive positions taken by a moving object in successive in- tervals of time. AMiether the picture takes the form of pictures in a row upon a transparent celluloid strip, as the original of Fig. 1, or whether it takes the form of a spiral line on a souvenir postcard, or whether the successive pictures were taken at the rate of fourteen per second, fourteen per year, or fourteen in one-hundredth of a second, all is immaterial, since in any of the cases the fundamental requirement is fulfilled and it is a picture of motion. Viewing Devices. The perfected projecting machine is but one form of viewing device. Just hold a slip of white paper above the film gate and watch the picture film as it enters the gate; the full motion of the drama takes place there. The intermittent mechanism pre- sents picture after picture at regular and proper speed, and the mo- tion of the picture is seen without projection. With the card of Fig. 2, the method of viewing is entirely differ- ent. The card is placed upon a light carrier, similar to the disk of a talking machine using the flat type of record; an eyepiece is con- veniently placed, and as the disk of the picture revolves with a step- by-step movement, the eyepiece moves across as the reproducer needle of the talking machine does. Thus the pictures are seen in order. By taking a transparent print from the negative, projection upon a small scale may be accomplished. With the picture strip of Fig. 1, it is necessary only to see the pictures successively, and preferably for ordinary scenes to view them in succession at the same speed that they were taken by the camera. To do this, some device is required to take away the first picture and substitute the second picture, then to take away the second picture and substitute the third, and so on indefinitely, that all of the pictures of the series may be \newed by looking at the same viewing position, as by looking at a screen upon which the pictures are pro- 80 MOTION HEAD 7 jected in rapid succession. Further, to attain the ilhision of motion in the picture, the spectator should be deceived, if possible, into be- lieving that he is looking at the same picture all of the time, at least in so far as the fixed objects of the picture are concerned. This illu- sion can be obtained by making the shift from one picture to another imperceptible to the spectator, which is done by making the time of shift as brief as possible, bringing it at least reasonably near to the limits of persistence of \nsion. Persistence of Vision, The human eye does not see an object instantaneously. Time is required for the muscles and nerves to act. ^^^lat length of time is required by the eye and brain to ap- preciate a view after the light has fallen upon the lens of the eye has not been recited, nor has it been told w^hat length of time is re- quired for the eye to cease seeing the vision after the light has ceased to fall upon the lens, for the eye is slow about quitting as well as beginning; but it has been established that the eye seems to see any view probably [one-fiftieth of a second longer than light actually falls upon the lens of the eye This action of the human eye is called by the name, "persistence of vision," because vision seems to remain or persist in action after the thing viewed actually has vanished. One effect of the persistence of vision is that, when two views are seen with an inter\'al of not more than one-fiftieth second between the two, the eye blends the two and, therefore, does not appreciate the interval of darkness which has occurred between the two. If the pictures are entirely unlike, there is a blur of confusion of the two. If the pictures are alike in some details and different in other details, then it seems to the eye that the similar details have not changed and that the unlike details have changed. In the dissolving lantern, with two views showing a different use of figures before the same background or scene setting, skilfully dissolved, it seems to the spectator that the background details have not changed, that the same picture has been viewed continuously, but that the figures of the picture alone have changed their pose. In the series of photographs of the procession studied as an example, it was by the comparison of a moving object with a fixed object in the picture that motion in the fixed object was proven. In the same manner, it is by comparison of moving and fixed objects 81 8 THE MOTION PICTURE in the projected motion picture that motion of the actors is made so realistic and so natural in its execution that it seems a reproduction of true hfe and the spectator is brought to realize that he is watching a picture of motion rather than a picture of inanimate things, or a picture in which motion is merely suggested as an art or trick or device. To secure this illusion, the fixed objects of the picture must remain absolutely motionless upon the picture screen. With the perfected motion pictures and motion-projecting ma- chine, exactly the illusion of the dissolving lantern is desired. Two successive pictures must be projected with such skill that the spectator is deceived into believing that he is looking at a single picture of a scenic setting or fixed objects of the picture, and that, watching a single picture, the moving objects^ have changed their positions. jNIany projecting devices embodying the principle of I he dis- solving lantern — namely, the principle of projecting the second pic- ture before the first picture is t;iken away and then of projecting the third picture before the second picture is taken away, and so on through the series — have been suggested and some of them have been operated successfully. However, the projecting device which has come into general use depends upon the phenomenon of the per- sistence of vision to smooth over the change from picture to picture, the change being made so quickly and so smoothly that the human eye cannot detect the coming of the new picture or the going of the old, nor guess at the interval of darkness or of blur which occurs between the two. Projection by Persistence of Vision. The method of projection which takes advantage of the persistence of vision fills the require- ments of the case entirely and is entirely satisfactory when well done. Its theory is that the first picture may be shown upon the screen, that the first picture may be cut off from the screen by a shutter, that the film may be shifted to bring the second picture in position for pro- jection, and that the shutter may be removed to permit the projec- tion of the second picture, all in a space of darkness upon the screen so brief that the first picture projected will persist in the vision of the spectator until the change in the motion head has been made and the second picture is upon the screen, when the spectator will see the fixed objects of the view in their places in the second picture as in the R2 MOTION HEAD 9 first, with the moving objects of the view changed to their next po- sition, whereby the spectator beUeves that he has had continuous vision and believes that the fixed objects have been upon the screen in fixed position all the time, and that the moving objects also have been upon the screen all of the time but that they have moved upon the screen to the new position. In the same manner, the second picture persists in the vision of the spectators until the dark interval is over and the shift has been made and the third picture is projected; the third picture persists until the fourth picture is projected, and so indefinitely until the picture is out, retaining all fixed objects in con- tinuous and stationary vision before the spectator by the phenomenon of persistence of vision and showing the motion of all moving objects in the successive pictures, the pictures showing so small an amount of movement between successive pictures that the motion seems smooth and continuous and not jerky step-by-step projection which it really is. That jerkiness, by the art of the film maker and assisted by the art of the projection operator, must be smoothed out. Motion Mechanism. The slowest speed at which it has been found practicable to project a series of images having ordinary motion, as of actors walking, and to smooth out the jerkiness which would be expected by the step-by-step nature of the projection when the persist- ence-of-vision method is used, is about fourteen pictures per second. Fourteen pictures are to be projected each second, and with uniformity. To expect the operator to make fourteen shifts, or fourteen voluntary motions resulting in shifts, each second, as in changing lantern slides, and to do it with regularity, is quite an impossible require- ment, so a machine has been devised for doing the shifting in an automatic manner, at regular interv^als, the length of the intervals depending only upon the speed at which the machine is driven. ^Vhen driven by an electric motor — a great convenience in some ways but a very great disadvantage in other ways — the entire op- eration is quite automatic, it being necessary only for the operator to adjust and start the machine and the projection of motion for some twenty minutes follows, presumably in an entirely satisfactory manner if the preliminary adjustments have been perfect, ^^^len not driven by a motor, the operator is provided with a crank, which is turned at a constant speed, and which results in the automatic shifting being performed under the driving power of the crank handle. 83 10 THE MOTION PICTURE The automatic shifting device is called a motion head, and it replaces in functions only the slide holder of the lantern, all the other portions of the fixed optical lantern being retained. All the features of the optical lantern for song slides are retained in use with the mo- tion head except the projecting or objective lens, a special lens for the motion pictures being carried upon the motion head itself. OPTICAL SYSTEM FOR MOTION PICTURES The optical system of the motion-picture lantern adds to the system of the stereopticon, two shutters, an intermittent shutter and a fire shutter. Because of the short-focus lens required for the greater magnification of the motion-picture image as compared with the fixed lantern slide, the motion-picture image or film strip of images is placed farther awav from the condensers than is the fixed slide. AVith these two modifications, the two optical systems cease their differences, and the fundamental principles of one are the fundamental principles -of the other. The arrangement of elements for the motion-picture sys- tem is shown in its usual form in Fig. 4, the picture screen or viewing screen, which would be located properly far to the right, being omitted from the picture in order that all the other elements might be drawn to a larger scale, more clearly and distinctly. Lamp. As has been described under the discussion of the optical lantern for fixed slides, the motion-picture arc lamp is of maximum strength, giving a very strong light and a very intense heat, such as is suitable for the motion picture alone, and unsuit- able for the lantern sHde. Condensers. The condensers are the same as used for the optical lantern for fixed slides, and are the same condensers, being carried by the lamp house from the motion head to the stereo lens, and again from the stereo lens to the motion head, but where the requirements for condensers for the motion head differ in any way from the requirements for the fixed lantern slides, the motion head should be given preference. Proper instructions for the adjustment of the condensers for the motion head are repeated here, as though they were to be used for the motion-head work alone. Back Condenser. This is the condenser at the left in the dia- gram, next to lamp L. It is shown in the diagram as the thicker of the two condenser glasses, and usually is so in practice. The 84 MOTION HEAD 11 focal length may he as short as 4^ inches. Its length of focus governs the distance of the lamp L from the back surface of the glass, and its length of focus in turn is controlled to some extent by the size of the lamp house, since the back condenser must take the rays of the lamp from a lamp position within the limiting range of move- ment permitted by the lamp house. INIost lamp houses will permit the use of back condensers 4 to 8 inches focal length. Fig. 4. Optical System for Motion-Picture Projection A — Feed Reel; B — Upper Steady Sprocket, or Top Feed: C — Condenser Case and Condenser Glasses; b — Presser Roller and .\mi for Top Feed; G — Film Gate; H — Tension Plate for Film Gate; K — Intermittent Shutter, Barrel Type; L — Lamp, or Point of Loca- tion of Arc; M — intermittent Sprocket; .V — Fii'e Shutter or Safety Shutter; O — Objective Lens or Projection Lens; P — Presser Roller and Arm for Intermittent Sprocket; S — Film in Film W'indow or Apertiu-e of Film Gate; .S" — Film leaving Intermittent Sprock- et to Basket. The dotted lines represent the outer rays of the beam of light, and pass to the right to.the Picture Screen, which is not shown in the figure. The shorter the length of focus of the back condenser, the thicker will be the glass in the middle and the closer must be the lamp L, consequently the greater the heat upon the surface of the glass; incidentally, also, the brighter the light upon the picture screen. On the contrary, with a condenser of longer focus, the glass will, be thinner in the middle, and will be farther away from the lamp, thus lessening the danger of breaking the glass. Incidentally, also, the less light will fall upon the condenser and, therefore, the less light will there be upon the picture screen. The length of focus of the back condenser may be considered a compromise between the strength of the light on the screen and 85 12 THE :\IOTIOX PICTURE the risk of condenser breakage. Any length of focus within wide limits — 4 to 8 inches, or in a large lamp house even much more than this — will give a properly distributed lighting of the screen, varying in brightness according to the length of focus used. The shorter length of focus for the back condenser will require greater skill on the part of the operator in keeping the light in focus. The light being nearer, a slight change, say, an eighth of an inch, in the position of the arc, will make more difference upon the picture screen than the same amount of change would make with a con- denser of longer fgcus. The longer focus of condenser (thinner glass) makes the lamp much easier to adjust for a smooth, evenly-lighted picture screen (provided always that your front condenser is of proper focal length) unless the back condenser happens to be so long in focal length that the lamp cannot be brought far enough back in the lamp house for it ; such a condenser is too long for the lamp house, and good projection cannot be had with it. Of course, some sort of quality of picture can be thrown upon the screen with it, but it makes poor projection. Front Condenser. This is the condenser at the right in the diagram, the outside one of the lamp house. It is shown in the diagram as the thinner of the two condenser glasses. The focal length should be exactly right to cause the rays of the lamp to come to a focus at the focal center of the objective lens 0, whose position is determined by adjusting it properly in focal length and position in the motion-head lens mount in order to focus the picture film S properly and in proper size upon the distant picture screen. Condensers are offered by all supply houses in lengths which vary by 1 inch, usually being offered in 4^, 5^, 6|, and 7^ inches. They may be obtained from the makers in focal lengths of 4, 4^, 5, 5i 6, 6i 7, 7i 8, 8i 9, 9^, 10, 10^ 11, and 12 inches. In addi- tion, they may be made to order of any length called for. With a 9 by 12 foot picture at a 50-foot throw, an objective lens at O having a focal length of about 4 inches would be required. In connection with this there would be required for the lantern slides a stereo lens having a focal length of about 12 inches. With a differ- ence of 8 inches between the two lenses, the distance from the lan- tern slide in its carrier to the motion-picture film in its gate .should be about 8 inches, equal to the difference between the lens lengths 86 MOTION HEAD 13 Taking the motion head as it stands on the table, the length of the front condenser is calculated in either case by simple addition. The focal length of the motion-picture lens is added to the distance from the film in its gate to the middle of the condenser box. In the instance taken, of a 4-inch lens, with 8 inches from the film to the slide position and another 2 inches back to the middle of the con- denser box, it gives a total length of 14 inches for the focal length of the front condenser. Tliis is the limit. A condenser longer than 14 inches will not give as good projection as one shorter; the front condenser should be 14 inches focal length or shorter. Condensers as a Pair. The condenser glasses should not be of too great difference in focal length, as the lamp adjustments again become difficult, and are easier with the condensers more nearly of equal lengths. For the maximum illumination in the instance considered, a 50-foot throw and a 4-inch lens, with 14 inches from center of condensers to center of lens, the theoretical focal lengths required would be a 5-inch glass for the back and a 14-inch glass for the front. This combination gives an equivalent focal length of about 4| inches for the pair of glasses. About the same equivalent length for the pair of glasses would be obtained by the combina- tion of a 57-inch glass and a 10^-inch glass, by the combination of a 6-inch glass and a 9-inch glass; by the combination of a C^-inch glass and an 8-inch glass; or by the combination of two 7-inch glasses. Of these combinations, the 5 and 14 combination would be the hardest to work in practice but would be productive of the best results when properly worked by the skilled operator. The 7 and 7 combination will not give good results with any amount of skill on the part of the operator. The best combinations to use are the 6 and 9 or the 5^ and lOi; the latter is better if the glasses can be ob- tained, and its use lies well within any careful operator's skill. Another consideration is the limits of the cone of light -iis deter- mined in dimensions by the position of the optical center of the motion- picture objective lens and the sides of the film-gate window. This must not be larger at the condenser than the face of the condenser glass. In the instance assumed, the diagonal of the f by 1-inch film- gate window is just Ij inches, and its distance from the optical center of the lens is about 4 inches (4.007"), while the distance from the optical center of the Ipus to the condenser face is about 13 inches. 87 14 THE MOTION PICTURE By the proportion, 4: I3 : : 13 :A, where A is the diagonal of the cone upon the condenser face, a vahie of 4 inches for the dimension A is obtained, which is easily cared for by the usual con- denser of 4J inches diameter of face when the condensers are of proper focal length and the lamp is properly adjusted. ^\^len the cone, formed l)y the limits of the optical center of the lens and the corners of the film aperture, falls outside of the front condenser surface, the corners of the pictures on the screen will be dark. The remedy is to move the motion head as a whole nearer to the condensers, even though this change should bring the focal center of the motion-picture lens nearer to the condensers than the focal center of the lantern slide lens, and thereby require a change from the motion head to the stereo lens, or back. For the best lighting of the screen, the front condenser should be as long as possible, but should be a little shorter than the limit, since the exact limit is hard for the operator to work satisfactorily, and a condenser a little too long is much worse for the picture than one a Httle too short. Short Rules for Condenser Lengths. The front condenser glass ihall have a focal length two inches less than the distance from the middle of the condenser hox to the middle of the 7nct ion -picture objective lens. The hack condenser should he five and one-half 'inches in focal length. The hack condenser may he four and one-half inches to force the light upon the picture screen at the risk cf breaking more condensers. The hack condenser may he six and one-half inches to reduce the breakage of condensers at the cost cf a slight reduction cf the brightness of the picture screen. When the front condenser is too short, the correction cannot he accomplished by suhstituti)ig the back glass with one a little longer. Use the longest focal length {the thinnest glass) for the front glass of the condensers. Lenses. The motion-picture lens is similar to the stereopticon or fixed picture lens in all respects except in that of focal length. It is similar in focal length, too, so far as the fundamental principles of projection are concerned, and its focal length, size of picture pro- duced, and required length of throw may be determined by the rules, both for approximation and exactness, which have been given in connection with the discussion of lenses for stereopticon work. 88 MOTION HEAD 15 TABLE I Showing Size of Screen Image Wiien Moving Picture Films Are Projected Size of Mask Opening IJ by Jg inch Equiv. Focus Inches 15 20 25 30 35 40 45 50 60 70 80 90 100 ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. ft. 2J- 4.8 6.4 8.0 9.6 11.3 12.9 14.5 16.1 6.5 8.7 11.0 13.2 15.4 17.6 19.8 22.0 21 5.4 6.8 8.2 9.6 10.9 12.3 13.7 16.4 7.4 9.3 11.2 13.1 14.9 16.8 18.7 22.4 3 4.5 5.7 6.8 8.0 9.1 10.3 11.4 13.7 16.0 6.2 7.7 9.3 10.9 12.4 14.0 15.6 18.7 21.8 3* 4.9 5.8 6.8 7.8 8.8 9.8 11.7 13.7 15.7 6.6 8.0 9.3 10.6 12.0 13.3 16.0 18.7 21.4 4 42 5.1 60 6.8 7.7 8.5 10.3 12.0 13.7 15.4 5.8 7.0 8.1 9.3 10.5 11.6 14.0 16.3 18.7 21.0 H 4.5 5.3 6.2 6.8 7.7 9.1 10.6 12.2 13.7 15.4 6.2 7.2 8.4 9.3 10.5 12.4 14.5 16.6 18.7 21.0 o 4.8 5.4 6.1 6.8 8.2 9.6 10.9 12.3 13.7 6.5 7.4 8.4 93 11.2 13.0 14.9 16.8 18.7 5h 4.3 4.9 56 6.2 7.4 8.7 9.9 11.2 12.4 5.9 6.7 7.6 8.4 10.2 11.9 13.6 15.3 17.0 6 4.5 51 5.7 6.8 8.0 9.1 10.3 11.4 6.2 7.0 7.7 9.3 10.9 12.4 14.0 15.6 GV 47 5.2 6.3 7.3 8.4 9.6 10.6 6.4 7.1 8.6 10.0 11.4 13.0 14.5 7 4.4 49 5.8 6.8 7.8 8.8 9.8 6.0 6.6 8.0 9.3 10.6 12.0 13.3 ~h 4.5 6.2 5.4 7.4 6.4 8.7 7.3 10.0 8.2 11.2 9.1 12.3 8 5.1 7.0 6.0 8.1 6.8 9.3 7.7 10.5 8.5 11.6 The difference between the size of the lantern-slide ^vindo^^' or the mask window of the slide, and the motion-picture window, must be borne in mind. The size of lantern slide usually calculated for in computing lens dimensions is 2f inches by 3 inches, a dimen- sion which io exceeded in many slides. In the matter of the motion picture as commercially used in the theater, the size of the window for projection is called | inch by 1 inch, is never more than that, and is never less than \l ly If inch. The projected picture of the motion-picture film always is about three-(juarters as high as it is wide, and this proportion must 89 16 THE MOTION PICTURE be taken into consideration when calculating upon the dimensions of the picture which is to be thrown upon the picture screen. The desirable results of operating lantern slides with a slide- carrier window mask have been discussed in connection with the operation of the optical lantern for fixed slides. The same good results are obtained in motion pictures by the use of a window mask in the window of the film gate, the aperture plate, as it is called, hav- ing an aperture just a little smaller than the pictures upon the film, so that the side lines of the picture upon the screen are formed not by the film picture but by the aperture plate of the motion head. INIost projecting machines are equipped with an aperture plate which "trims" the picture jV inch all around, reducing the size of the visible picture to y| by yf inch. Table I gives the size of projected picture with different lengths of throw and with different focal lengths of projecting lenses with an aperture or mask opening \l by y| inch. At the left in the first column is given the lengths of the lenses, from 2| inches to 8 inches, for which the table is computed. The columns at the right of the first column are arranged for the different lengths of thrown the length of throw considered in each column being mentioned at the top of that column. For each length of lens, there are two figures in the columns for length of throw. These two figures are the height and width upon the screen of the projected picture which will be secured by using the length of lens mentioned at the left of the pair of figures and using it wdth the throw mentioned at the top, above the pair of figures. From Table I may be obtained: The lens length required to give a desired picture when the throio is known. The size of 'picture which will he given by any certain lens when the throw is known. The length of throiv to be taken to secure a picture of a desired size with any certain lens. To Take Lens Length. Find in the table the length of throw which you have. This will be found as the number of feet men- tioned at the top of one of the columns. Now look down in this column until a pair of figures is found givi'ng the size of picture which you desire to project. AVhen this pair of figures is found, lay a card 00 SCENE FROM PHOTOPLAY, "THE HERDERS" Courtesy of Selig Polyscope Co., Inc., Chicago MOTION HEAD 17 across the book page, even with the lines and just showing above its edge the pair of figures showing the desired size of picture in the proper length of throw column. At the left of the lens table and just above the edge of the card will be the length of focus in inches of the lens required for that size of picture. Example. You have a 70-foot throw, and desire a picture about 12 feet wide. Finding the column marked at the top 70 feet and looking down that column, the pair of figures, 8.7 by 11.9 is found, and placing a card on the page the figure 5^ is seen at the left above the edge of the card. An ob- jective lens of 5h inches equivalent focal length -will give a picture about 8 feet 9 inches high by about 11 feet 10^ inches wide. To Take the Picture Size. Tn this problem, you have the lens which you are thinking of using, or must use, and you have the length of throw over which it must be used. At the left of the page, find the focal length of the lens in inches, either as marked on the lens, or as measured as described for stereo lenses for the optical lantern. Place a card across the page just below the figure of the length of lens, so that the card will show above its edge a row of pairs of figures of which in each pair the lower figure of the pair will be the larger figure. Now find the length of throw at the top of the narrow columns, and under that length and at the edge of the card will be found the pair of figures which tell the height and width of the projected picture when that lens is used over that throw. Example. You have a 4-inch lens and a 40-foot throw and desire to know what size of picture will be projected. At the left of the page find the figure 4 and place a card across the page so that it will show the row of figures beginning with 5.8 and ending with 21.0, thus showing a double row of pairs of which the lower figure of each pair is the larger of the pair. Now find 40 feet at the top of one of tlie narrow columns and below it is found the pair of figures, 6.8—9.3, meaning that with that lens and that throw the picture will be 6 feet 9^ inches in heiglit and 9 feet 3\ inches in width. To Take the Length of Throw. Knowing the lens which must be used and the size of picture desired, look at the left of the table for the lens length, place a card across the page and look along the card for the size of picture, then go up the column to the top and there will be found the length of throw which will give that size pic- ture with that lens. Example. In a parlor, a screen 6 feet square has been provided; you have only a 4-inch Jens. At the left of the page, find the figure 4 and lay a card across tlie page; the first pair of figures along the edge of the card is 01 18 THE MOTION PTCTFRE 4.2-5.8, which will go on the screen, but the next pair, 5.1-7.0, will give a picture too large for the screen. It is seen, therefore, that the operator must not place his projecting machine farther away than 25 feet (the figure at top of column above the pair, 4.2—5.8) or the projected picture will be too large for the screen. Accurate Calculations. ^Mien sizes are needed very accurately, they should be calculated according to the rules given for calculating data for lenses for lantern slides for the optical lantern, using the three equations; ST = PD (I) F2 = (^D - F)(T - F) (2) D + T = H (2) In these equations, when used in the calculation of data for motion picture projection, S equals the width of the film aperture or mask opening when calculating for the width of the projected picture — make S equal to 1 inch or % inch according to the dimension of the aperture — and equals the height of the film aperture when calculating for the height of the projected picture — make S equal to f inch or % inch, according to the dimension of the aperture. T equals the length of throw, lens to screen, which may be measured closely when the length of the lens is known approximately, and when T may be measured the equation for S may be written in a simpler form if desired. P equals the picture dimension as projected on the screen, being the height when 8 is the height and being the width when S is the width of the film aperture. D equals the distance from the focal center of the lens to the picture film in the film window; it is not required to be known in the course of calculations, but is included in the equations because it influences the size of the projected picture, sometimes as much as 1 inch in the width of a picture 12 feet wide. F equals the focal length in inches of the motion-picture objective or projecting lens. // equals the distance, screen to film. Approximate Calculations. Use the formulas or equations given for lantern slides. These calculations are useful when the exact length of throw is not given in the table. 92 MOTION HEAD 10 The throw equals the desired picture width multiplied by the focal length of the lens and divided by the film aperture width, all dimensions taken in inches. That is T = PxF -r S The lens length equals the film aperture width multiplied by the length of throw and divided by the desired picture width, all dimen- sions taken in inches. That is F = SXT -rP The picture width equals the film aperture width multiplied by the length of throw and divided by the focal length of the lens, all dimensions taken in inches. That is p ^ SXT -r F The picture height equals the film aperture height multiplied by the length of throw and divided by the focal length of the lens, all dimensions taken in inches. That is P = SXT -r F Calculations Compared. Assume a 4-inch lens and a 48-foot throw. The accurate calculation gives a picture size of 11 feet 11 inches, while the simpler approximate calculation gives a picture size of 12 feet, approximating the true picture size within 1 inch. Matched Lenses — Stereo and Motion Head. By the term matched lenses is meant a pair of lenses selected to work together, the one as a motion-head lens and the other as a stereo lens, and to give two pictures upon the screen which shall have the desired relation in size. Lenses may be matched for height, for width, or for area. If the screen is square, the stereo lens may be matched to project a picture as wide as the motion picture lens. If the screen is the shape of the motion picture, then the stereo lens may not project a picture higher Mian the motion-picture projection. If the screen is between the two, or if it is ample in size and the operator prefers a picture of equal area, the lenses may be so matched. The argument in favor of equal area is that the shift from lantern slide to motion film is less objectionable to the operator, but when the possible difference in densities is considered this objection seems to have little force. To match lenses for the samo width of picture on the screen, the stereo lens will be just three times the focal length of the motion 83 20 THE MOTION PICTURE Fig. 5. DiaRram of Edges of Pictures on Screen with Lenses Matched to Give Equal Area picture lens, figuring 1 inch as the width of the window in the film gate and 3 inches as the width of the mask opening of the lantern sHde. With the 'Ae-inch film wnndow, the stereo lens should have three and one-fifth times the focal length of the motion-head lens. For equal height of picture on the screen, |-inch high film window, and 2f-inch high lantern slide mask open- ing, the stereo lens should be three and two-thirds the focal length of the motion-head lens; and with a film T\-indow j^l inch, the stereo lens should be four times the focal length of the motion lens. For equal areas, the stereo lens should be three and one-third times the focal length of the motion-head lens for a film window f inch by 1 inch or full size of the motion film. The stereo lens should be about three and three-fifths the focal length of the motion-head lens for a film window || inch by ^-| inch. The arrangement or relation of the two pictures upon the picture screen when projected matched for area is shown in Fig. 5. Adjustable Lenses. These lenses are made to change the equiva- lent focal length of the lens by turning the front rim of the lens. Fig. 6. The knob moves the whole lens. Such a lens, at a 40-foot throw, will project a picture varjang, say, from 8 feet in width to 14 feet in width; that is to say, its focal length can be adjusted from 2h inches to nearly 5 inches by turning the front rim. After turning the front rim to change the picture size, the lens must be re- adjusted with the knurled knob to focus properly on the screen. The price is as much as two or three ordinary lenses of the same quality. Any lens will project its picture slightly smaller by imscrewing front and back lens cells a few turns of the screws. This is not to be rec- ommended for indiscriminate practice. Fig. 6. A Lens Having Adjustable Focal Length, for Motion Head 94 MOTION HEAD 21 THE SHUTTER In projection by persistence of vision, the secret of successful work is to make the change of picture on the screen without per- mitting the spectator to see or to appreciate the change in any way other than by the shift of the moving objects in the image portrayed. Theoretically, it is possible to shift the picture by a jerk so quick that the transfer from the old to the new picture is made without leaving upon the eye of the spectator an impression of mo- tion of the fixed objects because the motion was so brief. That this is possible is proven by the successful operation of many shutterless toy projectors, projecting film of standard dimen- sions by means of an oil lamp upon a small screen, such as 3X 4 feet. The picture is steady and flickerless. The result is dependent upon the weak illumination of the oil lamp. \Mien a miniature incandes- cent lamp is placed in such a toy machine and caused to glow brightly by a sufficient battery, thereby increasing the intensity of illumina- tion upon the screen, the shifting becomes apparent at once, mani- festing itself by "rain" or "light rain," sometimes called "halo." This is a streaking of the picture vertically, caused by the rapid passing of the light spots of the pictures while moving. To avoid "light rain," the motion head is provided with a shutter for cutting off the light from the picture screen while the film is in motion during the shift. This obscures the "light rain" and gives again a satisfactory projection, until the intensity of illumination is increased further, when the picture change begins to become apparent again, this time by a flickering of the illumination of the screen everv time the shutter cuts off the lig-ht for the change. To make the flicker less noticeable, effort is made to reduce the time of the dark inteiTal until it falls within the limits of persistence of vision. With the widely used "Geneva" movement for the inter- mittent mechanism, it is feasible to have the film stand still four- fifths of the total picture time of one-fourteenth of a second, making the change of pictures in the remainder of one-fifth of one-fourteenth of a second, or in one-seventieth of a second; but the shutter begins to cut off the light before the film begins to move and then does not restore the full light until after the film has come to rest, thus lengthen- ing the interval of reduced light. Furthermore, the more intense 95 22 THE MOTION PICTURE the screen illumination, the more noticeable is the flicker for the same shutter setting and the same machine speed, indicating that the bril- liancy of the picture screen has some effect upon the time during which the vision will persist. In the same audience, one person will see flickering pictures where another will not, because of the difference in the eyes. Suc- cessive scenes in the same reel of film will show flicker or not to the same spectator because of the difference in the opacity of the film image. A scene with a bright white sky will flicker unendurably to nearly all eves while the interior view following it will run smoothly because of the smaller amount of light on the screen. The multiple shutter is an invention for reducing flicker. It is used on many prominent machines. The form may be disk, barrel, or cone. The principle is that of shutting off the light twice, or three times for each picture projected, so that the rapidity of flicker is increased until the flicker becomes so fast that the eye cannot appre- ciate the separate flickerings and blends them all together into a con- tinuous steady illumination by reason of the persistence of vision. In the operation of this shutter, the light is cut off from the screen forty-two times per second and the picture is changed to the next step of the film only fourteen times per second, or every third time the light is cut oft'. ^Yith a shutter having but one blade, cutting the light from the screen only when the picture is being changed, four-fifths of the light of the lantern is projected to the screen. With the multiple shutter which shuts off one-sixth, then leaves the light on one-sixth, then shuts off one-sixth, and so on, the light given to the screen is three-sixths on and three-sixths off for every picture, giving but one- half of the lantern's light to the screen. Thus the multiple shutter reduces the maximum illumination and thereby reduces the flicker, even as flicker would be reduced if the operator would reduce the current through his arc and give a less bright projection in that way. The multiple shutter much improves the projection in the detail of flicker. Adjust the shutter accurately, whether single or multiple wing and keep the machine running fast enough to keep the flicker sul> dued. In scenes which have a particularly bright screen illumina- tion, the light may be reduced by a t inter, which is a sheet of colored 96 MOTION HEAD 23 glass or a plain colored lantern slide or the equivalent, which may be held either between the lens and the screen or between the con- densers and the film window Types of Shutters. There are two principal types of shutters, the barrel shutter and the disk shutter, the latter amplified ^o the double-disk shutter to secure the advantages of the barrel type. Barrel Shutter. The barrel shutter is shown in Fig. 7. This shutter is like a barrel with two windows cut in it. ^Yhen it is ar- ranged to shut off the light as a single shutter, cutting the screen dark once for each picture shift, then it revolves at one-half the speed of the inter- mittent mechanism, or one revolution of the shutter for two pictures. The light is admitted to the screen when the two windows of the barrel are opposite each other horizontally. The advantage which this shutter has over the disk is the speed with which it cuts the light from the screen and restores it after the shift. The blade near the lens begins to cut the upper rays and the blade near ^%\^.^q J^ihutter^ the film window begins to cut the lower rays, and when the shutter is half over the beam of light, the light has been shut off, because the shutter has worked upon both halves at the same time. In like manner, when the shutter begins to admit the light to the screen again, it begins at the middle and as the blades separate the light spreads upon the lens rapidly toward the upper and lower edges, restoring the full illumination very quickly. This shutter usually is placed between the lens and the film window, as shown in the diagram. For the multiple-shutter effect, the barrel shutter revolves once for each picture, cutting the light off twice. The blades then are wider, the windows smaller. Disk Shutter. The disk shutter is a plain disk with a window in it, or a hub with a single wing attached, revolving edgewise as shown in Fig. S. It is placed in any one of three places — between the lens and the film window; between the condensers and the film window; or before the lens. It is desirable that the light be cut off as quick as possible when the shutter begins to cut it off, and that it be re- stored just as quickly when the shutter begins to restore it. This ad- vantage was enjoyed by the barrel shutter over the disk shutter so 97 24 THE MOTION PICTURE long as the disk shutter remained of small radius; the small radius was enforced when the shutter was placed between the lens and the film window because it must be contained then within the body of the projecting machine; when placed between the film window and the condensers, its size was restricted also, because on the one hand it conflicted with the crank, and on the other hand with the stereo- lens beam of light. Before the Lens Shutter. The before-the-lens shutter solved the problem of the quick cut off for the light with the simple disk shutter. Fig. 8. The Disk Type of Shutter, with Two and Three Wings The shutter was placed before the lens and was made of large radius. The speed of the shutter near the edge of a lo-inch disk is seven times that of the shutter within the motion head which had an axis only 2 inches from the optical axis of the beam of light, and when the edge of the wing comes to the beam of light streaming from the lens, the beam is cut very quickly. True, the beam of light at this point is larger than it is between the lens and the film window, but the speed of the cutting shutter wing is still greater in proportion. With the disk shutter for the multiple shutter effect, it may carry three wings, each one-sixth of the circumference of the shutter, 98 MOTION HEAD 25 or the shutter of two wings may be driven at one and one-half times the rate of the picture shift to reduce the flicker, Fig. 8. Any shutter may give the multiple shutter effect to reduce the flicker by doubling the speed, where the mechanical details of the motion head permit it. Multiple-Disk Shutter. This is a shutter consisting of two disks revolving in opposite directions, so that they begin at the same time to cut off the light from both edges of the beam, just as the barrel shutter does. This makes the cut-off still more quickly than the single-disk shutter and serves still further to reduce the flicker. In multiple-disk shutters the disks are not always mounted upon the same shaft or upon the same axis, one disk sometimes working from one side of the beam of light and the other disk from the other side. Cone Shutter. ^Vith its driving shaft set at an angle of 45° to the beam of light, the cone shutter revolves its two wings — one in the beam of light and the other at the side- parallel with the beam. The cone shutter is a shape adapted to save space in the motion head, and give the advantages of the disk without taking the room. Setting the Shutter. Here is a short rule which applies to every type of shutter and to every type of intermittent mechanism: Place a piece of film in the motion head, threaded through the film gate and intermittent feed of whatever nature, and frame the picture true in the film aperture, splitting the margin of trim if you are running a % aperture on a |" picture. Then advance the in- termittent mechanism until the film is being shifted and is exactly in the middle of the shift. At this point, the line of division of the film between the two pictures u'ill be exactly across the middle of the film windoic. Noio set the shutter so that it is dead center over the lens, or dead center on the optical axis. If you have a multiple shutter and one of the leaves of the shutter is broader than the others, or if one is opaque and the others trans- lucent, then the broad leaf or the opaque leaf is the one to set over the lens when the film is half shifted. ^^ Another rule, which applies only to the Geneva shift and the disk shutter, is: When the pin is half in the slot, the shutter should be half over the lens. 99 26 THE MOTION PICTURE Fire Shutter. The fire shutter, or safety shutter, shown at A"^ in Fig. 4, is a requirement of most city ordinances. It is a shutter for cutting the rays of the arc lamp from the film window when the motion head is not running. It is called automatic when it is so arranged that it will fall into place and cut oft' the light when the film stops, without requiring the attention of the operator to close it. Sometimes its mechanism is such that when the handle is turned it is lifted from the film window automatically, and sometimes it is such that a definite speed must be attained before it will be lifted from the film window. This fire shutter is a detail wliich varies greatly with different makes of motion heads. Its general purpose is the same in all — to protect the film from the intense heat of the arc in case the film should stop in the film window, for the arc would cause the film to burst into flame in a few seconds. FILM GATE The mechanism of the film gate is so simple that unless its fiuictions or the duties dependent upon it are understood the pro- jection operator is liable to neglect it. It is one of the ver}' important parts to be kept in exact condition of adjustment and to be corrected when the slightest wear shows, for one of its duties is the keeping of the focus constant upon the screen. It is of little use to adjust the objective lens to focus the film upon the screen in one minute when the film gate will change the position of the film and throw it out of focus the next. Functions. The functions of the film gate are: First, to guide the film so as to prevent any side wise motion as it passes in front of the film window in the aperture plate. Second, to flatten the film at the film window and hold it flat so that all of the surface of the film picture may be thrown into focus upon the picture screen by a flat-field lens, and to hold it in the same plane all the time so that the focus when once established by the ad- justment of the objective lens will be maintained to the end of the reel and through successive reels. Third, to prevent vertical jiggling of the images of the series in their comparative locations in the film window, by putting upon the film a tension or restraint to keep it from following by its momentum after the intermittent mechanism has stopped pulling. 100 MOTION HEAD 27 Construction. The main plate has t^o side guides or rails and a film aperture or film window. The two side rails are separated sufl^ciently to permit the film to pass between but not to take any diagonal position. When threading up the machine, the film is placed in the groove formed by the face of the film gate and the two shoulders or rails forming the side guides for the film; and the ten- sion plate or tension springs are brought to bear upon the edges of the film. In Fig. 4, the body of the film gate is represented at G and the tension plate at //. The springs are not shown. Adjustment of Tension Springs. Where the tension springs do not make direct pressure upon the edges of the film, the tension plate is pressed by tension springs which are adjustable. If the tension of these springs is too tight, they will drag the film at such strain that a weak place or splice will separate under the pull of the intermittent feed ; if the tension of the springs is too loose, the picture will "follow" and the projected image upon the screen will jiggle vertically. As the tight spring does not manifest itself imless it be by tearing the film or causing the handle to turn hard, it is less easily detected upon inspection than the loose spring, W'hich permits the picture to jiggle. The adjustment of the tension springs may be attained, therefore, first by setting all of them to the same tension, then by loosening them equally until the picture begins to show upon the screen that the tension springs are too loose; then by tightening them until the picture is steady again. Thus they will be tight enough, without excess pressure. Care. The film gate and the tension plate both wear where the film rubs between them; where the springs press directly upon the film, the springs themselves wear. Any wear which can be de- tected will probably be enough to throw the picture out of focus upon the screen from time to time, particularly a film which is slightly warped. The only remedy for a worn film gate, which permits the focus of the picture to vary from time to time as the reel is turned through, and the lens remains stationary, is to buy new parts — gate body (with some makes of machines it is the "aperture plate"), or new ten- sion plate, or springs, or all of them. Wear can be reduced and the machine will pull easier on the handle if the film gate and tension plate surfaces, which are rubbed 101 28 THE MOTION PICTURE by the film, are kept free from any gelatine which may come off of the film. Clean them every time by wiping before threading up the new reel, and by wiping with an oily rag every time a new reel is put in — the rag should be oily but so dry that it is not running oil when squeezed in the hand. Never oil them with an oil can. FILM SHIFT OR INTERMITTENT MOVEMENT There are many variations in devices for stepping the strip of film forward the three-quarters of an inch from one picture to the next of the series. The requirement of such a device is very severe, for the step must be made with great speed and with great accuracy, and furthermore the film must be permitted to remain perfectly motionless during the interval between steps. A class of projectors, which does not use the intermittent movement, will be considered in connection with continuous projection devices. The different mechanisms for making the shift of the film upon the step-by-step principle are: the sprocket; the pin; the claw; the beater; and the intermittent grip. Intermittent Sprocket. The intermittent sprocket is a wheel with two circles of pointed teeth spaced a trifle more than 1 inch apart upon the surface of a drum about 1 inch in diameter, or spaced upon two hubs or bosses to hold them at that distance, the metal being cut away to render the wheel light of weight and easily started and stopped. The sprocket teeth are spaced so as to engage the perforations of the edges of the film strip, and the film is advanced step by step by turning the sprocket wheel intermittently, usually one- quarter of a revolution for each step of the film. For turning the sprocket wheel in its intermittent motion, a large variety of devices have been employed, and a new one is brought out occasionally. The only test for a new intermittent movement is the test of time. Nearly all intermittents ever used have given place to the Geneva, which was among the earliest of them all. Geneva or Pin=and=Star. The Geneva movement comprises a star wheel shaped like a modified Maltese cross and attached to the sprocket shaft, and a pin wheel which revolves steadily. Every time the pin comes around it catches a wing of the Maltese cross and throws the cross around one-quarter of a turn, leaving it there until the pin comes around again. 102 MOTION HEAD 29 A Geneva movement — it is called Geneva because it was used first in Geneva, Switzerland, in watches, with one of the wings of the cross convex instead of concave so that the main spring of the watch could not be wound too far — is shown in perspective view in Fig. 9. At the left is the star wheel, with four slots and four wings each having a concave outer face, as indicated at A. The pin wheel is seen at the right, and consists of a flat disk or face plate carrying a pin B and the cam band C. The cam band is cut away on both sides of the pin and the pin is set outside of the cam band circle, or a litde farther from the center hole of the disk. When the pin wheel revolves, toward the left, say — although it depends upon the particular projecting machine or camera inspected, for the Geneva move- ment may be on either end of the intermittent sprocket shaft — the pin moves toward the left and when the pin comes to the star wheel it enters the open end of the slot next to the wing which has been against the moving cam band; but the cam r^- „ ^ t . •.. . »c o ' Fig. 9. Geneva Intermittent Movement band now has released that wing and the pin in moving into the slot presses against the side of the wing and turns the star wheel as two meshing gear wheels would turn each other, except that the pin starts the star wheel slowly, swings it rapidly during the middle portion of its movement, and again slows it up to a standstill before leaving the slot. The pin enters the slot, which is shown diagonally upward to the right, and having turned the star one-quarter of a revolution the pin leaves the same slot diagonally downward to the right, the cam bend hav- ing come around following the pin to engage the concave surface of the next wing before the pin has left the slot entirely. The advantages of the Geneva movement are: (1) It starts the film with a slow movement, increasing the speed to a maximum, then decreasing the speed until the film comes slowly to rest. (2) It holds the film or sprocket firmly locked during the interval of rest between shifts. (3) It is very easy in the wear of the sprocket holes of the film because of the lack of jerk in starting the film. (4) It is 103 30 THE INIOTION PICTURE very gentle with weak or injured places in the film which might yield and permit the film to be torn apart if suddenly jerked. (5) It is capable of construction in such proportions that any desired ratio of time of movement as compared with time of rest may be attained. To change the ratio of movement and rest of the sprocket wheel and film, the relative diameters of the two wheels are changed. With a larger diameter of pin wheel, the breadth of the wing surface A which rests upon the cam band will be a smaller part of the whole circumference, hence the pin B must affect the shift of the star w^heel, sprocket, and film during a smaller proportion of its total travel, or of one revolution. The ratio between the diameters of the two wheels determines the ratio of movement to rest, the ratio of rotation beino- four of the pin wheel to one of the star wheel in any case, re- gardless of the relative diameters of the wheels. Double Star. The double star movement consists of tw^o Geneva movements working in the same machine, one above the film gate and one below the film gate. The theory is that they assist in keep- ing the film flat by keeping it taut between them, also that they reduce the strain upon the film by giving the lower sprocket less pulling to do. This mechanism sometimes operates both star wheels from one pin wheel, in which case there are two pins in the pin wheel, the two pins operating the two stars simultaneously. Double Pin. The double pin movement is merely a modification of the Geneva movement by w^hich the star wheel takes a step every half revolution of the pin w^heel, instead of every full revolution. It is shown in diagram in Fig. 10. The only advantage urged is that the speed of the pin wheel is reduced to half that required were the single pin used. The simple Geneva is the more widely adopted. Pitman. The pitman movement is illustrated _. ,„ T^ ,, TT in Fig. 11. The intermittent sprocket is carried Fig. 10. Double-Pm ^ r ^^°®Moveraent"^" ^y *^^ ^^^^^^ Carrying the ratchet wheel R. Since the ratchet in the figure is shown with seven teeth, the sprocket attached would require twenty-eight teeth to feed the standard four-hole film. The wheel C is the constant drive, and the face of the wheel C carries a wrist pin driving a pitman bar, 104 MOTION HEAD 31 Pitman Intermittent Movement which in turn drives the pawl engaging into the ratchet R. The pawl upon the top of the ratchet R prevents return of the ratchet during the return stroke of the pitman and driving pawl. As the wheel C may be designed to drive the pawl over a greater stroke than the distance between two ratchet teeth, this device also may have a designed ratio of time of movement to time of rest; unless the movement is approximately half-and- half the start of the film will be a sudden jerk. Ratchet. The ratchet movement is ^^s- n. illustrated in Fig. 12. The sprocket wheel is attached to the same shaft as the ratchet wheel M and the ratchet-shape wheel iV is driven steadily. The wheels move in the same direction, as is indicated by the arrows, and they are connected by a volute spring. With six teeth in the ratchets, the sprocket would have twenty-four teeth for a standard film. The pawl N swings upon a fixed pivot and engages both of the toothed wheels. Its function is to hold the intermittent wheel ^f at rest until the pawl is lifted by the steady drive iV, at which time the pawl slips the tooth of the intermittent, but in turn slips a tooth of the steady drive so soon thereafter that it drops toward the intermittent wheel to engage the next tooth of that wheel and to hold it at rest until the next release, as compelled by the steady drive N. The film is started by this mechanism gently by the power of the spring con- necting the two wheels M and N , but it is brought to rest with a jerk by the engagement of the intermittent wheel M with the pawl P. Drunken=Screw. The drunken-screw intermittent movement involves a mechanism which is substantially a worm and wormwheel, Fig. 12. Ratchet Intermittent Movement 105 32 THE MOTION PICTURE but the worm, instead of being inclined through its full length, is straight for the greater part of the circumference and then has a Fig. 13. Dnmken-Screw Intermittent Movement sharp angle. The wormwheel, therefore, stands at rest during the passing of the straight portion of the worm thread, and moves rapidly during the passage of the inclined portion of the thread. The worm- wheel, which is shown at K in Fig. 13, is attached to the intermittent shaft, and the drunken screw or worm G of that figure is steadily driven. Snail. The snail intermittent movement comprises two wheels normally out of engagement, one of which engages a projection of the other with an incUned edge which propels the companion wheel through a required angle. This movement is shown in Fig. 14. The intermittent wheel P is provided with a number of pins, and the snail S engages a pin at every re- volution and forces the intermittent wheel P through the desired angle. Fig. 14. Snail Intermittent Movement Fig. 15. Spring-Latch Intermittent Movement Spring Latch. The spring latch intermittent movement has as its distinctive feature the holding and centering of the sprocket for each film picture by means of a bent spring which engages either one tooth, by a notch in the face of the spring, or two teeth of the wheel, by dropping between them with two inclined faces. When II 106 Q =" > •= i H :?~ « o < BP to i:ti w go MOTION HEAD 33 such a wheel is pushed over the apex of the spring it is propelled by the spring to its next position of rest and held there until again pro- pelled by the steady drive. Such an intermittent movement is shown in Fig, 15. The smaller wheel is the film sprocket wheel, or fixed to the film sprocket shaft, while the larger wheel propels it inter- mittently, making a step every time a tooth of the large wheel en- gages a tooth of the 'Small wheel. Single=SprGcket. The single-sprocket intermittent movement is shown in Fig. 16, which really is a revolving claw movement. The Fig. 16. Single Sprocket Intermittent Movement Fig. 17. Modified Drunker-Screw Intermittent Movement, End and Top Views sprocket wheel moves with steady rotation and has two pairs of teeth. As the first of these pairs of teeth swing against the film, they en- gage the holes in the edge of the film and drag it down, leaving the film unengaged until the other pair of teeth come into engagement for the next shift. iyiodified Drunken=Screw. A modified drunken-screw inter- mittent movement is shown in Fig. 17. The intermittent wheel 23 tends to move by friction clutch from the main drive, in the direc- tion of the arrow. It is prevented from movement, however, by the engagement of its teeth 24 with the face of the steady drive wheel 25, which has the upwardly turned wings 29. The steady drive 107 34 THE :\I()TIOX PICTT'RE shaft is 20, the intermittent shaft is G. The spring 30 holds the wheel .13 against the face of the wheel 25 and prevents backlash, locking the film steady during the intervals of rest. When the next tooth 29 of the wheel 25 comes to the tooth of the wheel 23, the wheel 23 is started with a blow and travels under its friction clutch until the next tooth engages the face of the wheel 25. Fig. 17 shows a view of the face of the intermittent wheel 23 and the edge of the steady drive wheel 25 in the upper drawing, and the edge of the intermittent wheel 23 and the face of the steady drive wheel 25 in the lower drawing. The arrows show the direction of rotation. Eccentric Sprocket. If the lower sprocket-roller of a machine revolves continuously on a fixed axis, it will, of course, continue to draw down him. If, however, it is mounted so that while it revolves its axis also rotates eccentrically about a radius equal to the radius of the sprocket, the film will be moved intermittently, the sprocket simply rolling up along the film for part of a revolution without moving it. Fig. 18 shows its arrangement as it is used in the Prestwich camera. The sprocket is driven by a train of gears. Fig. 18. Eccentric Sprocket or Epicycloidal Intermittent Movement Fig. 19. Pin-Cross Intermittent Mechanism Pin=Cross. The pin-cro.ss intermittent mechanism shown in Fig. 19 has been offered lately. Its construction seems to indicate 108 MOTION HEAD 35 strength; the design of the cam band indicates that the shift is made in a \ eiy small proportion of the total time of revoliition. It is, there- fore, a movement bearing promise, to be proven bv use. The move- ment is so new that it still lacks an accepted name, but the name pin-cross seems to be descriptive. In this movement, the member shown separated at the right, consisting of a cross of four arms, each of which bears a pin, is the member attached to the intermittent sprocket shaft. Thus attached, it meshes into the cam wheel at the left, as showm in dotted lines. When the broken or active part of the cam band reaches the pin-cross, the slight projection upon the outer edffe of the small cam between the ends of the band throws the leading outside pin outward, drawing the leading inside pin into the slot before the end of the cam band, the following outside pin also taking the cross path after the end of the cam band, the following inside pin becoming the leading inside pin and the leading out- side pin becoming the following outside pin. Thus, the pin-cross is turned one- quarter of a revolution, to shift the film, and is held rigid by engagement with the cam band at four points, by the four pins, until the cam wheel has completed another revolution and has come to the point for initiating another shift. Silence is one of the claims for this new move- ment. It is used on the Power's Cameragraph No. G, which is ad- vertised to give the complete film shift in one-ninety-sixth of a second, giving the complete shift of the film in one-sixth of a picture interval and running sixteen pictures per second, if desired. Pin. Pin intermittent movements are those in which the teeth engaging the holes in the film are not the teeth of a sprocket wheel, but are teeth fixed to some reciprocating member which gives them the four movements necessary to control the film with pins, namely, (1) to advance the pins into the holes of the film, (2) to move down- ward, dragging the film, (3) to withdraw the pins from the holes in the film, and (4) to return to the point of starting in readiness for advancing into the next holes of the film to repeat the cycle. Fig. 20. Theory of Pin Intermittent Movement 109 36 THE MOTION PICTURE Fig. 20 shows the theory of such a film movement. The pins P are carried vertically by the action of the crank C of the steady drive shaft D, which shaft carries also the cam wheel R in the edge of which is a groove which controls the pins P for their lateral move- ment, advancing them into the film holes and withdrawing them as required. The slot of the cam wheel R is straight except in tw^o places, for advancing and retreating the pins, one of the inclined places of the cam slot being shown in the figure just above the level of the pins P. The adjustment of the cam wheel R and the crank C with angular KA A o o 3 d' k g Fig. 21. Pin Intermittent Movement Taking the Four Movements from One Cam relation to each other is such that the pins C are shoved into the holes of the film by the cam wheel R just as the pins come to rest at their upper limit of movement, and they are withdraw^n just as they come to rest in their lower limit of movement. The time of motion of the film is, therefore, just one-half the total picture time, the film remaining at rest during the remaining half of the picture interval. 110 « MOTION HEAD 37 Another design of pin movement, suitable either for the direct action of the pin upon the fihn or for action of the pins upon a sprocket shaft for intermittent sprocket motion, is shown in Fig. 21, which iUustrates the device in four of its positions of operation, and shows it equipped for driving a sprocket shaft intermittently. The sprocket shaft, or intermittent shaft, is shown with six pins, and the teeth of the intermittent driving movement are show^n near the middle of each of the figures. The triangular cam is the steady drive member of the device, and it has such form that it fits the four sides of the square surrounding it at all times. In the upper left-hand drawing, the teeth are withdraw^n from the pin of the intermittent wheel; in the upper right-hand drawing, the triangular cam has turned and has advanced the teeth to enclose one of the pins upon the intermittent wheel, which as yet has not been moved; in the lower left-hand drawing, the tri- angular cam has moved further and has lifted the teeth enclosing the pin of the intermittent wheel, thereby driving the intermittent wheel through one-sixth of its rev- olution; in the lower right-hand drawing the triangular cam has moved further and has with- drawn the pins from engagement with the pin of the intermittent wheel, and is in readiness to be lowered into the position shown in the upper left-hand drawing, to repeat the cycle. Another type of pin movement is shown in Fig. 22, where the action is attained by two cams. The pin pair is located at the top of the vertical lever upon the wrist pin, which drives it vertically as a pitman rod, but at the same time the top of the vertical pin lever is rocked to the right and to the left, as view^ed in the figure, by the arm which is attached to it near the pins at the top and which passes to the right. By means of this auxiliary cam connection, the pins are advanced into the film holes when the lever is at the upper limit of its stroke and are withdrawn when it is at the lower limit. Fig. Pin Intermittent Movement from Two Cams 111 38 THE INIOTION PICTURE Still another type of pin movement acting directly into the film holes is shown in Fig. 23. The two cams are upon one shaft, one, Vwy Fig. 23. Pin Intermittent Movement Taking the Foiir Movements from Two Cams on the Same Shaft a triangular cam, providing for the Aertical movement, and the other a circular cam, providing for the movement toward and from the plane of the film. These cams take the proper angle on the shaft to provide for insert- ing the pins into the film holes while the pins are at rest in their vertical movement. Claw. The principle of the claw in- termittent movement is shown in Fig. 24. In this figure, S is the film with perforated edges, preferably only one hole per picture ; D is the steady drive shaft, P a pitman rod, R a reciprocating frame carrying the claw, and C the claw itself. The opera- tion is merely that of a pawl upon a rack or ratchet, the film being the ratchet or rack and the holes being the spaces be- tween the teeth for thv claw or pawl to engage. As the pitman rod 112 Fig. 24. An Intermittent Mechanism Built Upon the Claw Principle 4 MOTION HEAD 39 draws the reciprocating frame up, tlie claw rides on the edge of the hole until lifted out of tiie hole, then it rides upon the film under pressure of its spring until it reaches the next hole, when it drops in. When the pitman then drives the reciprocating frame down, the claw drags the film down, and again rides up to the next hole. The pin and claw movements both are very severe in wear upon the holes of the film. They are suitable for cameras where the film is passed through the machine but once; frequently they are found on projecting machines of an older type. Beater. The principle of the beater intermittent movement is that the film shall be taken up constantly, and at a constant rate, Fiff. 25. An Intermittent Merhanism of ilie Beater Type but that there shall be a definite amount of slack pulled through the film gate into a lower film loop just below the film gate, this slack being pulled through once for each picture interval, to shift the picture in the film window. The amount of slack in the film loop between the film gate and the steady drive take-up wheel shall be greater than the picture length of the film, so that the take-up wheel never pulls directly upon the film at the film gate but acts only to 113 40 THE MOTION PICTURE 5- take up the slack pulled in by the beater. The beater may be a wrist pin upon a face plate, or it may be a spring-propelled or pitman propelled device, or any reciprocating part whatsoever. IVrist-Pin Type. The wrist-pin type of beater intermittent movement is shown in Fig. 25. The steady drive wheel is shown as a drum at D with the presser roller P. The beater pin B is upon the face of the wheel B' and the wheels B' and D are geared together by a pair of spur gears. As the pin B passes over the top of its travel, the wheel or drum D takes up the slack between D and G, or takes up a definite measure of the slack, although perhaps not all of it. Then as pin B passes downward it pulls upon the film and draws through the film gate G just as much as has been taken up by the drum D since the last pull. The amount of film pulled through the film gate G does not depend upon the size, character, position, or radius of rotation of the beater pin B, but does depend upon the amount of rotation of the drum D , or the amount of lineal travel of the surface of the drum D for each revolution of the beater pin B. Pitman Type. The pitman type of beater, illustrated in Fig, 26, shows the beater mechanism alone. The film *S is shown as a heavy line from top to bottom of the figure, ben't between the two fixed studs, A and C, which may be merely idler rollers, by the thrust of the beater roller B. The beater roller B is carried upon the pitman rod D which is driven by the crank E upon the steady drive shaft F. The film gate of the figure is assumed to be above the mechanism of the figure, and the steady drive take-up device is assumed to be below, taking up between shifts the slack pulled into the film by the beater roller B, or at least a part of that slack. In this device, as in all beater devices, the amount of film drawn into the film gate by the action of the beater roller is not dependent upon the characteristics of the beater roller or of the fixed studs co-operating with it, but depends solely upon the amount of film travel over the take-up drum during a single revolution of the steady drive shaft F. Spring- Bar Type. Tlie spring-bar beater is still another type of beater intermittent mechanism. It consists of a beater roller Fig. 26. The Pitman Type of Beater Intermittent Mechanism 114 MOTION HEAD 41 mounted upon a spring-pressed bar, which bar is restrained by a ratchet mechanism until the shift is desired, when it is released to strike the film so as to draw the slack into the film loop, being im- mediately picked up by its restraining mechanism again, and again held until the instant of the next shift. Intermittent Grip. The intermittent grip mechanism, shown in Fig. 27, is in a class by itself, but never has come into general use. It operates without perforations in the film. The two wheels revolve toward each other, and when the enlarged places meet with the film between them, the film is gripped and drawn downward through the film gate. The amount of film pulled at each such meeting, Fig. 27. Intermittent Grip Mechanism that is, at each revolution of the pair of grip wheels, depends upon the length of the gripping surfaces which meet each other. Framing is accomplished by shifting the rollers slightly so that their ends overlap, the extending ends not being effective in pulling the film, and thus reducing the amount pulled. For the greater part, all mention of intermittent mechanisms other than the intermittent sprocket feeds are historical, the sprocket being almost universal at the present time for projecting machines; many of the variations in intermittent mechanisms, and particularly in pin mechanisms, are found in cameras for taking motion pictures. 115 42 THE MOTION PICTURE Adjustment of Intermittent Movements. The customary ad- justment provided for the internu'ttent movements for taking up wear lietween the wheels or cams is the eccentric bushing. This bushing, which is inckided as a part D of Fig. 9, is placed in the hole in the frame through which the drive shaft of the intermittent movement passes, and the drive shaft itself passes through the hole in the bushing, indicated by the small dotted circle. By turning the bushing slightly in the frame, the position of the drive shaft is changed verv slightly as compared with the movement of the bushing, and a very accurate adjustment is possible. The cams should be adjusted when properly oiled with a medium heavy oil — a very light oil will not stav on the cams and a very heavy oil is too sticky for the rapid cam motion. If adjusted dry, there will not be room for the oil to work between the cam surfaces without making the adjustment too tight, and if adjusted with a surplus of oil the oil will work away and leave them loose. The adjustment of the cam band of the pin wheel and the concave wing of the star wheel must be very accurate or the picture will lose its steadiness on the screen, taking a slight vertical jiggle. Many Geneva movements are fitted with an "oil box or tank and run immersed in oil. The pin and claw movements must be kept carefully adjusted, particularly as to those cams which give the film the vertical move- ment. The film teeth of these mechanisms wear rapidly and should be examined frecjuently a!id replaced when wear is detected. In the beater type of mechanism, the beater roller usually is cut away in the middle and strikes the film only on the edges, outside of the picture space. With rollers thus cut away in the middle, the remaining bosses which strike the film are likely to become worn conical, tapering toward the inside, resulting in irregular action of the film and consequent jiggling on the screen. In adtlition, a worn beater roller wears the film by bending it. The edges of the celluloid film in the holes engaged by the sprocket teeth or pins or claws are sharp and hard enough to cut away the teeth which grip them and particularly because of the rapidity and of the almost innumerable times that the film is gripped, j)ulled, and loosened in the course of a few months' use of a project- ing machine in a theater. Wear of the teeth engaging the film acts upon the film, for the teeth wear into a hollow on the pulling face, 116 II MOTION HEAD 43 making the point of the tooth of sHghtly liooked shape, and these hook teeth pull against the edge of the holes and tend to tear the film as they leave it. Worn teeth must l)e watched for and replaced when noticed. Sprocket wheels are interchangeable, and new ones can be bought from the projection machine makers and placed on the motion head with little trouble, or new rings of teeth can be bought and placed upon the old sprocket drums or bosses. Some types of sprock- ets are especially constructed with interchangeable teeth, and new tooth rings may be bought at a very low price to replace the worn ones. In addition to watching for wear and loose adjustments, the moving mechanism of the intermittent and all other parts of the motion head should be cleaned periodically, say, every two months if the machine is running evenings only and is giving no trouble, and every two weeks or every month if the machine is running all day, even though giving perfect service, and with no indication of trouble. Wipe off all oil, and empty the oil bath of the intermittent movement if it has one. Run the intermittent tank full of gasoline and turn the machine for a while to work it thoroughly through the cams; of course it will work out through the journals of the oil box and wash those clean. Wipe it off as it comes out, using a clean rag. Next, the mechanism should be oiled liberally with a very light oil to wash out the residue of the evaporated gasoline, and this light oil then should be followed with the standard body of oil regularly used on the machine. The gasoline (or even kerosene) loosens the dirt, the light oil carries out what the gasoline left by its too rapid evaporation, and the journals then are clean and ready for their standard working dose of regular lubrication. Do the same for all of the journals, putting oil in the oil holes with a can spout and wiping it off as it runs through — first gasoline, then very thin oil, then regular lubricator — loosen the dirt, wash it out, then oil up for service. The toothed surfaces of the gear wheels should be cleaned in the same way, for they pick up grit very freely. If after cleaning the gear wheels they rattle a little, wipe them as dry as possible and hold a lump of beeswax against the teeth and turn the handle of the motion head through several revolutions. This will quiet the noise without injuring the gears. 117 44 THE MOTIOxV PICTURE CONTINUOUS PROJECTION Any system which will keep the illumination constant upon the screen will be independent of the disadvantages of flicker, and possibly other disadvantages may be avoided or disadvantages obtained by devices designed to project the second picture upon the screen before the first is removed, as with the dissolving lantern. Four methods of attack, none of which has come into general use, have been used for this problem, viz, duplex projection, moving lenses, moving mirrors, and moving prisms. II II i! I! f r~\ Fig. 28. Duplex Projection \y Fig. 29. Continuous Projection by Moving Lenses Duplex Projection. Duplex projection consists of projecting from two lanterns with a dissolving shutter, each change dissolving from the old picture to the new, and each lantern shifting its film to the succeeding picture while the viewing screen is under full illumination from the companion lantern. The arrangement of the two lanterns driven by one motor is shown in Fig. 28, the lanterns indicating by the dotted lines that the central rays projected reach the same point upon the picture screen. At the right of the lantern diagram is seen the front view of the 118 MOTION HEAD 45 before-the-lcns shutter M which is pLaced between the two lanterns and acts as shutter for both of them. The white half is the open half, the dark quarter is opaque, and the remaining portions are semi-transparent. These semi-transparent portions of the shutter extend the dissolving of the view and make it a little softer than a simple half-and-half shutter would give. Moving Lenses. jNIoving lenses for continuous projection are shown in Fig. 29, which is a front view of the projecting machine. The lenses of the chain are spaced | inch apart — just picture dis- tance — and each of them follows a picture down as the film passes Fig. 30. Continuous Projection by Moving Mirrors with steady motion through the film window, which is nearly as long as two pictures. There is no intermittent mechanism in this pro- jector. The middle lens at the left of the chain is shown in the middle of the projection window, and as the lens now" visible through that window passes downward with its film image, the next lens will approach the projecting window from the top. The top and bottom edges of the projecting windows are substantially shutter edges, and as the following lens comes into action at the top of the window, the preceding lens will go out of action by passing behind the lower edge of the window. Thus, a dissolving effect is secured, and continuous illumination of the screen is effected, changing the images without intermittent mechanical motion. 119 46 THE MOTION PICTURE Moving Mirrors. Moving mirrors for continuous projection are shown in diagrammatic perspective in Fig. 30. The large vvlieel is a wheel of shutter leaves, carrying the picture film upon its surface, or upon the edges of the shutter leaves which form a series of windows over which the pictures of the film are stretched. In the center of the wheel is a drum of mirrors which is arranged to turn at half the speed of the drum of shutters carrying the film strip and pictures. At the left is the lamp house and the dotted lines show the course of the beam of light ;^^^^•y^.^^^'-^^^^^^^^^^^^^y^'^ ^V^^^V- V^'.V^^^V-vV.^W.WJ Fig. 31. Projecting Machine for Continuous Projection by M oving Prism from the lamp house through the condensers in the front of the house, through the film, through the single lens to the drum of mirrors, then to a fixed mirror and then downward, whence the beam carries to the picture screen. Again there is a continuous illumination of the screen without any intermittent mechanism. Two mirrors of the drum in the center always will be working in the beam of light between the lamp house and the screen, one mirror projecting the upper and the other the lower portion of the picture seen upon the screen, except at the instant when one mirror ceases and another begins the projection. 120 ^rOTTOX HEAD 47 Moving Prisms. Moving prisms for continuous projection are shown in Figs. 31 and 32. Fig. 31 shows the diagram of the com- plete projecting machine from condensers to objective lens, and Fig. 32 shows two diagrams disclosing the course of the rays forming the beam of light through the film, prism, and olijective lens. No inter- mittent mechanism is used. Steady Feed Elements. The motion head projecting by inter- mittent motion of the film is provided with two elements of steady feed for relieving the film from the jerk of the intermittent as far as possible. If the intermittent feed were required to pull the film from the feed reel, turning the reel in so doing, and if also the take-up reel were allowed to pull directly upon the teeth of the intermittent sprocket, the wear upon the film and upon the sprocket would be ^.c Fig. 32. Diagrams of Course of Light Rays in Continuotis Projection by Means of Moving Prism great. This is much reducerl by providing upper and lower steady feed sprockets, relieving the intermittent mechanism from all duty but the shift of the short piece of film in the film gate, the film being brought from the feed reel down to the upper end of the film gate by the upper steady feed sprocket, and being held slack below the intermittent and fed to the take-up reel under proper tension by the lower steady sprocket. In order that a proper looseness of film, or slack to avoid strains, may be had above and below the inter- mittent feed, the film is formed in^o slack bends which are known as upper feed loops and loicer feed loops. 121 '48 THE^MOTIOX PICTURE THREADING UP THE MOTION HEAD The course of the fihn through the motion head, the elements which operate upon it, and the method of placing the film in position may be studied at the same time, taking the steps in the order in which they are encountered by the film in its travel. Feed Reel. The feed reel is a spool upon which the picture film strip is wound when ready for projection. It consists of a core from H to 2^ inches in diameter, with a spring clip for taking the end of the film which is to be the inside end of the reel; the reel then is turned and the film is wound upon it, a strip of 1,000 feet of film filling the reel to a total diameter of about 10 inches. The 10-inch reel has upon its core two sheet-metal flanges equivalent to spool ends, which are about 10 inches in diameter. Winding the spool full of the film to be projected, beginning with the "end of the picture" or "tail" of the film, and finishing with the "title" of the picture or "leader" of the film upon the outside of the spool, is called rewinding, and when so wound, or rewound it is ready to be placed in position. Feed=Reel Magazine. An iron fireproof box with a fire-trap film outlet is provided for receinng the feed reel. The feed reel, in response to the pull upon the film by the upper steady feed, turns loosely in this fireproof magazine. Place the full feed reel in the upper magazine, start the lead end of the film through the film outlet at the bottom of the feed magazine, just above the motion head, and close and fasten the feed magazine door. The feed reel is shown without its fireproof magazine at 1 in Fig. 33. Upper Steady Feed. The lead end of the film is pulled out about 3 feet, the presser roller is lifted from the upper steady feed sprocket and the film is laid upon the surface of the sprocket drum with the teeth of the sprocket passing properly through the holes in both edges of the film. The presser roller is dropped upon the drum with its spring, or there may be two such presser rollers, or an idler roller between the upper feed and the feed reel. In Fig. 14, an idler roller is shown at 2 to direct the film to the upper steady feed sprocket 3 at the top of the sprocket so that the film will wrap a full half-way around the sprocket and get the benefit of a pull by a large number of the sprocket teeth. The presser roller — or friction roller as it is sometimes called, though friction is no part of its function— is shown by the small circles just below the sprocket 3, not numbered. 122 = ^ a 2' = > ^^ =» o Sis W H <; [I. H '.^ A ^ a, a e Pi O M So O 1^ s & C"i o gg M K H •:; s o Z MOTION HEAD 49 Upper Feed Loop. The film is formed into the upper feed loop before passing to the film gate, that is, the film gate is opened and the film is placed in the groove of the body of the gate, the film being lifted from 2 to 6 inches higher in the gate than it would be if stretched straight from the top steady feed sprocket to the gate. The film in the gate is carried into engagement with the intermittent sprocket teeth, and the door of the film gate is closed upon it, clamping it in position. The placing* of the film higher in the film gate leaves a looseness in the film above the film gate and between the film gate and the upper steady feed sprocket, which forms the upper feed loop, as shown at 4 in Fig. 33. At every shift, the intermittent feed pulls some of the slack out of this loop, and between shifts the upper steady feed feeds the film down to replenish the slack pulled out by the intermittent. Film Steady Drum. In some motion heads the film is not permitted to feed directly from the upper feed loop to the film gate, but is taken over a drum which guides it into the entrance to the gate. This film steadier is shown at 5 in Fig. 33, and its presser roller is shown by the small cir- cles just above the drum 5. Film Gate. The film gate is indicated at G in Fig. 33. It is of many types, but usually has a door to be opened, and a groove into which the film is laid and upon which the door is then closed. Intermittent Sprocket. The teeth of the intermittent sprocket or of the intermittent feed of any type usually are so closely associated with the film gate that they substantially run in the sides of the groove through the body of the film gate, so that at one operation the film strip is placed in the groove of the gate and upon the teeth of the intermittent ^ig. 33. Dia^am Showing Film-Feeding Elements of tlie Motion Head 123 50 THE MOTION PICTURE mechanism. The intermittent sprocket is shown at 7 in Fig. 33, and its presser roller is shown by the small circles just below it. Lower Feed Loop. The lower loop is formed as the upper loop was, by placing the film upon the lower steady feed sprocket from 2 to 6 inches higher than it would lie if drawTi straight from the intermittent mechanism (jr film gate. The lower feed loop is shown at 8 in Fig. 33. The intermittent pulls three-ciuarters of an inch of film into this louver loop at every shift of the pictures, thereby increas- ing the size of the loop, but the lower steady-feed sprocket takes the film up steadily and takes up the exact amount of film before the next shift. Lower Steady=Feed Sprocket. This sprocket is shown at in Fig. 33, and its presser roller is shown by the small circles just above it. In this figure the presser rollers of the upper steady sprocket and of the friction drum are placed upon the same arm, while the presser rollers of the lower steady sprocket and of the intermittent sprocket also are upon the same arm — this is a matter of preference and convenience for the operator as differently designed by the different manufacturers. The film now is taken over the idler W — which is omitted in some motion heads— to the take-up reel. Take=L'p Reel. This is substantially the same as the feed reel. If the end of film leader which was drawTi out of the feed magazine to begin threading is not long enough to reach the take-up reel, the handle of the motion head may be given a few turns, feeding the film down. The end is passed into the take-up magazine through the film outlet (which is an inlet this time) and the end is fastened under the spring clip upon the hub of the take-up reel. I'he slack of the film between the take-up reel and the lower steady feed is wound up by turning the spool itself by hand, then the motion-head handle is given a turn or two with the take-up magazine door open in order to make sure that the take-up is working properly. Then the door of the take-up magazine is closed and you are ready to light up, start the crank, open the fire shutter, and "let 'er flicker" — for slang ceases to be slang when it is simple truth. The take-up must be watched particularly at the beginning of the film reel, and particularly toward the end of the film reel, when the take-up reel is nearly full, is heavy to move, and moves slowly on account of the long distance around it. The take-up reel moves 124 MOTION HEAD 51 more and more slowly as the spool gets more and more nearly full, and some compensation is required between the speed of the reel, always varying, and the speed of the driving handle, which is constant. This compensation usually is provided by a friction drive for the take-up reel — perhaps, a pair of friction plates held together by a spring; perhaps, two grooved wheels belted by a belt which is supposed to pull tight enough to pull the heaviest load and yet slip rather than tear the film or stop the operator's arm. These friction devices should be noted and kept in proper adjustment, for a friction device can hardly be expected to stay in adjustment very long, as the plates wear smooth or get grit between them, and the belts stretch. The friction device must drive the take-up reel fast enough to take up the film on its small center when the film is just starting, and must not pull so hard that it will pull the film apart in its weaker spots. Excess friction makes the handle turn harder. Framing Devices. The word "frame" when applied to the projection of motion pictures refers to the position of the projected image upon the picture screen, or to the position of the film image as related to the film windows. "When the top of the picture is at the top of the screen, or at the bottom of the film window, and the picture just fills the screen and the window, the picture is said to be "in frame," tlie image fitting the film window as the lithograph fits the frame on the cottage wall. Wnen, by reason always of improper adjustment of the film or of the motion head, the top of the picture on the screen is a few inches from the top of the illuminated area upon the screen, and the lower edge of the next picture shows across the top of the picture being projected, then the picture is said to be "out of frame," and when examined in the film window it will be seen that the little image does not register with the window. As films may be defective in median portions, the motion head must be able to frame while running. Framing is accomplished by shifting the film with reference to the lens or film window. Somewhere about the motion head — and its position and general appearance varies with different makes of machines —will be found a framing lever, ^^^len the motion head is standing at rest, and when the framing lever is moved, {!) the lens and film window will move upward or downward with the film remain- ing stationary in the gate; or {2) the film gate and intermittent las 52 THE MOTION PICTURE mechanism as a whole will move upward or downward, the lens remaining stationary; or (5) the intermittent feed alone will move as a whole and will draw the film downward or try to push it upward through the film gate; or (4) the intermittent sprocket will rotate a little in one direction or the other, without changing the location of its shaft; or (-5) a little slack will be taken up or let out in & framing loop formed for the purpose of framing, and located between the intermittent feed mechanism and the film window. Framing is usually and most easily accomplished by looking at the picture projected upon the screen. The picture may be brought approximately to frame by looking at the film window after thread- ing up the head and before beginning projection. The final adjust- ments, like the final adjustments of focus, should be made by watch- ing the picture screen during projection. The framing lever always has a movement of more than one full picture. When you try to "frame up" and the lever will not move far enough to frame the picture, then "frame down" nearly a whole picture instead and the proper adjustment can be reached. Rewinding. When the reel of film has been turned through, the tail end is allowed to run through to the lower steady feed, then is caught and taken back to the feed reel. The main drive handle may have a shift to throw it to a rewind position, or it may have to be removed from the main drive shaft and placed upon the end of a special rewind shaft; in either case, the turning of the handle when changed for rewinding will turn the feed reel rapidly and will wind the film back from the take-up to the feed reel and at a much faster speed than the speed of projection — one to two minutes to rewind a reel which took twenty minutes to project. The laws of New York and possibly of some other states do not permit the rewinding of film in the projecting room. It must be taken from the projecting machine in the reel and rewound to a feed reel. Two reels mounted edge to edge, near each other, with a crank and gear on one of them, is the rewinding device then used. Automatic Rewind. Devices for avoiding the rewinding of the film before a second projection have been suggested and tried. Fig. 34 shows a well-known projector equipped with the automatic rewind, or rather with such a relation of take-up and feed devices that no rewind of any kind is recjuired. The feed magazine feeds 1 126 i .MOTION HEAD 53 from the middle of the roll of film and the take-up reel rolls the film up with a large center hole, so that the operator may take the roll of film from the take-up magazine, drop it into the feed magazine, start the inner end through the film outlet and thread it through his motion head back to the take-up, and his machine is ready for another projection of the film. Not only does this sort of improve- ment save the operator's time and labor, but it saves wear on the film, which becomes scratched in rewinding at high speed. ■i ^ s Ln 9 ^ IP^^' \ j > ^ WF Fig. 34. Projector with Automatic Rewind Another type of machines joins the leader to the tail of the reel and runs the picture twice or more without stopping, if desired. No automatic rewinds are in general use in theaters as yet, though the type illustrated in Fig. 34 was widely sold at one time, and the endless belt type is used in penny arcades. Film Basket, or Molasses Can. The take-up reel goes wrong in operation oftener than any other one part of a projector. Often the operator must stop the show to set it right, and in the middle of a picture reel. A more reliable method is to let the film rim from the lower steady feed into a sheet-iron can or box of 2 or 3 cubic 127 54 THE MOTION PICTURE feet, folding up loosely as it mns in. It is rewound from this can to the feed reel. Because of the early practice of letting the film run into an open basket, with its comparatively great fire risk, this take-up can is still called a "film basket" by older operators, while it is called a "molasses can" also from the manner in which the film folds down into it. AMiere the fire ordinances of the town permit it, the can will be found to "give a better show" than the take-up reel; it is less wearing on the operator and on the film. Operator's Control of the Picture. There are two features in which the operator has control directly for modifying the picture — sfeed of projectioJi and brightness of light o)i the screen. Framing is not a matter of arbitrary control, it is merely a necessary detail which must be kept in adjustment. The picture may be improved by reducing flicker when possible by reducing the illumination, either by a lamp adjustment if con- venient, or by a tinter; preferably the tinter, since by remwing the tinter the full illumination is restored immediately when a dense scene is projected in the run of the same reel. Flicker may be reduced by speeding up the rate of turning, also. In the case of a picture having the upper part of the screen white sky and the lower part dark foreground, the illumination must be retained to make the foregroimd visible, and the only means for reducing the flicker is speed. The sentiment of the picture may be watched and speed may be used accordingly, the operator turning more rapidly where he fleems the action of the picture could l^e improved thereby. The manufacturer should have timed his action when making the picture, l)ut sometimes this is neglected. Motor versus Crank. Most cities prohibit the motor for turning the motion head. The way to keep the operator attending closely to his film is to keep him at the machine turning the crank, hence all other methods of driving the motion head are forbidden, ^^^lere the motor is permitted, a small electric motor of the usual fan size, tV oJ" tV horse-power, will drive it. In case the motor is used, the film always should be started and turned for 50 feet or more with the crank before the motor is switched on. This gives the operator the "feel" of the machine and tells him whether everything is running as it should. Then the labor is turned over to the motor for the 128 MOTION HEAD 55 greater part of the run of the reel. Just before tlie end of the reel the operator should take his erank again and shut off his power, again assuring himself by half a minute of hand turning that his projector is in perfect running order and does not require repairs or readjust- ment before starting the next reel. The operator's hand upon the crank is the doctor's finger on the pulse of the patient; the slightest irregularities in mechanical action are noted by the "feel" of the handle. The operator's eye must be upon the screen practically all of the time for framing and focus, even if not for flicker. FILM Films of all makers for general commercial use are made to about the same size, If inches wide, ^i^o i"<^'h thick including celluloid and gelatine; of this width of If inches, a strip down the middle 1 inch wide is reserved for the picture and the holes are punched in the margins near this strip, ^\ of an inch apart. The various makers follow this standard rather loosely, because it is itself rather loosely composed and rather indefinitely expressed. One of th(^ most prominent points of variation is the shape of the hole used; another is the distance between the two rows of holes, or the distance from either edge to the nearest row of holes. A movement is being made to work out a standard, expressed accurately in thousandths and split thousandths of an inch. It is believed that the life of films will be lengthened if all are alike and the projector may then be built accurately to that film size. Care of Film in Projecting. Fit the film accurately to the sprockets before starting projection. If possible, look through the reel for bad edges, bad splices, or unframed splices before beginning pro- jection, and repair any troubles found. Listen to the purr of the film over the steady feed sprockets and bad places in the sprocket holes will be detected when running. Watch the screen for unframed splices and for focus; a film which rims out of focus for a few seconds at a time and then runs true, constantly varying the focus while the lens and film are unmoved and the film gate is clean and perfect, may be warped; it shoukl be moistened, as discussed under the sub- ject of warped films. If a film rattles as it leaves any_ of the sprockets, the teeth of the sprocket may be worn into hooks; a new sprocket is the proper remedy. 129 56 THE MOTION PICTURE Care of Film in Rewinding. Rewind under steady tension. Do not rewind loose and then holding the film take up the slack by winding the center of the coil tighter; that grinds into the film any grains of dust which may have been collected and which otherwise might be brushed off. In rewinding, the film may pass over a soft rag, or through a soft rag held bunched in the hand, to wipe oft' the dust, the first time it is rewound. Particular care must be given to the gelatine side of the film in order to avoid scratching. Care of Film in Storage. The film should always be packed in metal cans or flat boxes when setting it away. It must not be kept in a warm place as the celluloid will give off explosive gases, the gelatine will dry out and warp the film, and the celluloid will shrink with the heat, particularly if it be an XI (non-inflammable) film. Care in Handling Film. Do not let the ends of the film become unrolled; they are liable to a sharp bend which leaves a crease and ultimately a break. Keep the roll flat when off the reel. The dropping out of the middle in a cone shape and pushing back again only adds scratches where none are needed. Handle by grasping the flat of the reel which is the edge of the film, and handle as little as possible. Packing for Shipment. Place the film first in the iron box, then in the wood box, and see diat the danger label which the film exchange puts on is still on the outside of the box. In unpacking, see whether the box is fastened with screws, if so use a screwdriver, not a hatchet; and use the same box for re-shipment to the film exchange. Repair of Films. The usual method of repairing films is to cut out the defective place and splice the ends together, thus reducing the length of the film by the few small pictures cut out with the bad place. Where a crack is seen starting across the film, it is easier to take a piece of clear celluloid film strip from which the gelatine has been soaked and cement h inch of it across the film over the crack, than it is to splice it. This is cemented upon the glossy side, leaving the gelatine and the picture image intact, and it saves the order of pictures in the film without causing a sudden jump of the moving characters when the fault is reached in projection. The film thus repaired is no thicker than a splice, and will pass the sprockets and film gate with the same ease. The patch should not be more than one-half a j)icture in size, or the film will be stiffened more than a splice would stiffen it. 130 MOTION HEAD 57 ^Miere the sprocket holes have a bad spot, a piece of blank film (with the gelatine soaked off) may be attached sometimes to avoid cutting out good images. Film Splicing. Cut one end on the hne between pictures; cut the other end with a quarter picture on; thus in cutting a film there will be three-quarters of a picture cut out, a picture and three-quarters, etc. Moisten the gelatine on the quarter picture and scraoe it clean: ol ' A lo r Ol jo o| B io Ol lo o| IO 1 0| C lo Oj ]'=' oi \ O lo oi D |C oi lo 1 oi lo o! lo 1 oi E io Ol IO Oj 1° oi F 1 !0 Oi A O o[ o o! o! B o o oi o oi^ o Oj C o 0[ o ol o Ol D o O! o oi o Oi o oi £ o oi o Oj o Oj oi F o o *■ — *— Fig. 35. A Splice "In Frame" Fig. 36. A Splice "Out of Frame' also scrape the celluloid side of the other end clean. Spread cement on the cleaned quarter picture space and put it on the back of the other end, sticking the two ends together with the picture Hues matching and with the sprocket holes matching. Cut either through a sprocket hole or midway between sprocket holes, straight across the film. Small scissors are more convenient than a knife. 131 58 THE MOTION PICTURE Splicing hij Machines. A number of forms of splicing machines are offered. All of them have teeth for registering the sprocket holes while the spHce is setting, and all of them require special instruction and some skill of hand and common sense. Either with or without the machine, get some scraps and practice on them until you can make it right. Your film exchange or a friend operator will give you a handful of short pieces for practice; and the cement is twenty-five cents for a very small bottle. A fiat stick is the best cement spreader. Non-lnjiammahle Film. In splicing a non-inflammable film a special cement is required, the XI film cement being suitable for either ordinary film or NI film. Splicing "in Frame." Splicing a film "in frame" may be under- stood by a study of the companion figures. Fig. 35, which shows a splice "in frame" and Fig. 36 which shows a splice "out of frame." In Fig. 35, the picture C has four holes at the side, just as have the pictures A, B, D, E, etc., and when that film is passed through the film gate and intermittent mechanism, the "framing" will be preserved, because mechanically the film is the same in distribution of pictures and of sprocket holes as though no splice had been made. The difference is found in the "jump" of the pictures where a picture or more have been omitted, but the "frame" will not be disturbed as the splice passes. In Fig. 36, the picture C has but three holes at the side. The result is that when the picture B is pulled out of the film window and the picture C is pulled in, the intermittent mechanism pulling down four holes will pull into the film windoAV the three-cjuarter picture C and also the top quarter of the whole picture D • Again, upon the next operation of the shift mechanism, the intermittent feed pulls down four holes, the picture C will be pulled down, and there will be jiulled into the film window the remaining three-quarters of D and the top quarter of E. This will continue, showing the lower three-fjuarters of one picture and the upper quarter of another, until the (>j)erator notices the screen and frames with his lever. This is called a splice "out of frame," because the splice throws the picture out of frame in passing. Framing hy Splicing. Every time a splice "out of frame" is passed, the operator must "frame" with his lever until he can find opportunity to stop in rewinding and cut the faulty splice. Then he 132 MOTION HEAD 59 may splice it correctly "in frame" and thus put his reel of film in frame at that place when running. Titles. Titles should be given the same care as the picture scenes of the film. The main title, forming the head of the picture film, should be given the favor of a very long leader if the title itself has been shortened, so that there wall be ample leader to thread through to the take-up reel, to turn a few pictures to test the working of the take-up before closing the take-up magazine door, and further to turn a few pictures and get the motion head under speed })efore opening the fire shutter. Thus, the audience will get the full benefit of whatever title there is. Leaders and Tails. The purpose of the leader and tail is to give the audience the benefit of all of the picture which lies between. The leader is a piece of blank film or a piece of scrap film, just so it has good sprocket holes, cemented to the title end of the reel, and of sufficient length to thread through the motion head and test the mechanism before bringing the title into the film window. The tail is a similar piece cemented to the end of the picture. Its purpose is to enable the operator to run the full picture on the screen before closing the fire shutter, then to stop his motion head before the tail has run into the take-up magazine where it cannot be reached con- veniently for rewinding. Some motion heads are so constructed for rewinding that if sufficient lengths of leader and tail are provided neither end of the film need be detached from either reel if but one reel is to be run repeatedly in the projector. Stopping the motion head before the tail has been drawn from the spring clip of the feed reel, the film is rewound and the rewinding stopped before the leader is drawn from the spring clip of the take-up reel; the motion head then is threaded and the film is ready to repeat. Blank black film mav be bought from the film exchange for leaders and tails if the reels come too short for the operator's convenience. Dry Film. The gelatine of the motion picture strip is charged with glycerine by the manufacturer in order to keep it elastic and to make the film pliable in handling and projecting. As the glycerine and the water which is held in the gelatine gradually dries out, owing to winding and rewinding through the air and the heat of the arc lamp, the film strip becomes dry and brittle, with a tendency to crack the gelatine film, which then tends to scale off from the celluloid. 133 GO THE :M0TI0N PICTURE Films may be moistened and their pliability restored by leaving them unrolled over a little water, not permitting the water to touch the film. Take a bucket holding four or six gallons, cut a false bottom of heavy wire mesh or perforated metal with legs or downturned edges to hold it 1 inch from the bottom of the bucket. Pour in \ inch of water, set the false bottom in, and run in a reel of film, let- ting it fold around as film does in a basket from the projecting machine. Cover the bucket for half an hour. ^Mien the film is reeled up it will be found much more pliable. Warped Film. With the film in a close roll, the drying from the edges goes on more rapidly than from the central portions of the strip. This warps the film, making it take a cun-ed section crosswise of the film when it should lie flat; and it takes the cun-e sometimes in the film window, putting the picture out of focus on the screen. Such a film may be treated with the vapor bath as described above, or it may be treated more simply by cutting two disks of thick felt the size of the end of the reel, dampening them, putting one on each side of the reel, wrapping it and letting it lie over night. Discretion must be used to avoid getting the felt or blotting paper too wet. OPERATOR'S DUTIES Before the Show Begins. The operator usually is held respon- sible for delivery to the tlieater of the film for projection. If in a city where the film exchange is visited, the operator makes the visit, returning the old reel and bringing the new to the theater. If in a town distant from the exchange, he is responsible for the packing and shipment of the old reel and the receipt of the new one and its delivery from the express office to the theater. Such deliveries may be daily, or only once a week. Being thus the messenger to the film exchange to obtain the picture film, he is also made responsible for getting the song slides, and not only the slides but the sheet music for the singer which is supposed to accompany the song slides but sometimes does not except after a special effort to get it. If tide posters are used, the operator is held responsible for their delivery also, as being some- thing substantially a part of the film reel. Being thus in charge of the signs for the theater front, it is good if he can improvise signs with a brush and a sheet of paper when occasion requires, 134 MOTION HEAD 61 or when the title poster for a particular reel of film cannot be obtained as usual. The operator is responsible for keeping up the necessary supply stock for the operating room — carbons, oil, and condensers for the lantern; film scrap and film cement for repairing films; cover glasses and binding strip for repairing slides. Whether he purchases the supplies himself or asks the manager to purchase them is immaterial. If the supplies run short, he will get the blame, hence the burden lies on him to buy or keep kicking. Preparing for Projection. On going into his iron-bound cage to prepare for the projection of films and lantern slides for the after- noon or evening, the operator should turn the motion head at a good fast rate for the "feel" of the machinery; then clean the film gate, notice the gate and tension plate and sprocket teeth or intermittent pins for wear; then oil up ready for the run; clean the lamp, dusting out the carbon dust which collects in the bottom of the lamp house from the sparks thrown off from the arc; examine the lamp and con- nections to see whether any wires are burning weak from the heat of the arc, and whether any joints are loose; dust the table top, and lastly sweep off the lens surfaces with the camel's hair brush; inspect the carbon stock, and if insufficient for the day it may be necessary to omit the dissolving lantern or to set the rheostat to a lower notch to save carbon; inspect the new reel of film, if time is had, strengthen- ing any weak spot found and framing up the reel by resplicing "in frame" any splices found "out of frame"; trim the lamp with car- bons of sufficient length for the first reel, light up, center and focus the light, put in a slide to be sure that the stereo lens is still in focus; then put a piece of scratched mica (not celluloid) in the film gate for the test of the motion head lens for focus. He now is ready to begin projection. Conducting the Program. The duties of the operator after the projection begins were discussed in an article which appeared in the N ickelodeou and which seems to cover the subject. It reveals the fact that the operator has duties other than turning the crank, and that training in actual service beyond the mere mastering of the mechanism of some particular projecting machine is an essential to the person who would become an efficient operator and valuable theater employe: 135 62 THE MOTION PirTl'RE Every nickelodeon has its stage manager, whether it knows it or not. There must be of necessity among the attendants of a motion picture theater some one who decides when the pictures shall start, when the song shall be sung, and how long the intermissions between the performances shall be. This person is the one who really is in charge of the program of the theater, and upon him depends to some extent both the pleasure of the patrons and the profits of the owner. In a small theater, running to one reel of film onlj^, without songs or specialties of any kind, the total manual duty connected with this duty of controlling the program is the turning off of the lights in the room when the pictures start, and turning them on again when the performance is finished. This requires merely a switch in the operator's booth, convenient to his hand, for the house lighting .system. In such an instance, the operator rewinds the reel of his film and adjusts the carbons of his lamp. He is ready to start the next performance. At this point, it is within his discretion to start the performance immediately, to delay it according to a time schedule, or to delay it as long as he thinks the audience will endure the wait without impatience. It can be seen plainly that the pleasure of the patrons and the profits of the owner lie within control of the person who is in charge of the program. As the theater acquires additional features of entertainment the duties of controlling the program become more and more complex. By adding an illustrated song, the operation of the projecting machine becomes more complex. In addition, the operator must have a push button to call the singer at the proper time to be in readiness when the song slides come upon the screen. If an automatic piano or phonograph is running as a barker in front of the theater and is making so much noise as to interfere with the enjoyment of the song (it may be noted that patrons sitting in the rear of the room will be much nearer to the automatic barker than to the singer), then the automatic barker must be stopped during the song, requiring another switch to be controlled by the operator. If ventilating fans are running in the theater during the pictures, these in all probability must be stopped during the song, since the whirring of the fans, not at all objectionable during the pictures, would be decidedly so during the song. With an illustrated song an accompanist is required; this usually dispenses with the expense of an automatic piano, the accompanist playing during the intermissions. The operator in control of the program therefore is required to call the accompanist as the program nears the close, that the intermission music may start promptly at the close of the pictures. What, then, are the total duties in such a theater which are required of the operator usually thought of as only a picture-machine operator? Take the easiest form of .song-and-picture program, in which the pictures follow the song. In the intermission, the pianist is on duty. The operator, having his picture film in readiness, (1) lights his arc and (2) rings for the singer. He then (3) turns out the lights of the auditorium, (4) turns off the ventilating fans, (5) turns off the automatic barker and (6) projects the song slides in proper order and at the proper instant for each. At the conclusion of the song, he (7) shifts to the motion head and begins to turn the crank of the 136 MOTION HEAD 63 kinetoscope, and at the same time, with his free hand, (8) he turns on the ventilating fans and (9) turns on the automatic barker. This is the time for the accompanist's period of rest, and as the operator nears the end of the reel he (10) rings for the accompanist to be in readiness for the intermission. At the end of the motion pictures he (11) projects the Please Remain slide; then (12) turns on the auditorium lights, (13) cuts off the current from his arc light, (14) rewinds the film and (15) adjusts the carbons of his arc lamp. Last, but by no means least, the operator (16) decides the length of the intermission before repeating his routine of sixteen separate duties. With every added feature of entertainment, the operator's duties become more complex. An alternative plan of managing the performance consists of placing a stage manager at the theater entrance, inside the auditorium, and providing him there with all necessary control facilities. An array of electrical switches control the barker, the house lights and the ventilating fans; push buttons are arranged to ring buzzers or bells in the operator's booth and in the waiting room of the performers in the rear of the picture screen. An answering buzzer circuit may run from the waiting rooms to the stage manager's station, or even a telephone line may be installed. In the picture machine operator's booth there is merely one switch controlling the current for his arc lamp and one button' which rings a buzzer at the stage manager's station. This system operates as follows: When the machine operator is in readiness, having rewounel his films and adjusted his lamp, he signals to the stage manager by pushing his button; then he merely awaits the command to go ahead with the projection. When, in the judgment of the stage manager, the performance shall begin, he rings for the singer and signals the operator (two buzzes for the song slides) and when the first slide flashes upon the screen the stage manager cuts off the house lights and stops the barker and the fans, '\^'ith applause after the song, the stage manager uses his discretion as to whether an encore shall be sung, and either rings again for the singer and signals to the operator (three buzzes to put the chorus slide back on the screen) or rings one buzz to the picture machine operator to go ahead with the motion picture film without encore; at the same time, the stage manager starts the fans and the barker. As the pictures near the close, the stage manager rings for the pianist and then turns on the house lights as the picture closes. He then must wait for the buzz from the operator indicating that the projecting department is in readi- ness again. ^\ hen vaudeville or specialties of any kind are added to the perform- ance, the duties of the stage manager become more complex, and the machine operator, whose post is a responsible one, should be relieved of them. Keeping Up With the Times. The live projection operator who desires not only to give a good show and hold his present jol) hut also to fit himself for a better one, must keep posted upon the new ideas that are being developed in the art of projecting and theater operating, and the new devices which are being produced constantly by enterprising manufacturers. Subscribe for some motion picture 137 64 THE MOTION PICTURE magazine, and read not only the feature articles of the magazine, which attract attention first because of their illustrations, but read the editorials and the advertisements. Read particularly, and] with care, the department usually entitled "Manufacturer's Depart-] ment" or "Notes of the Trade," a department which is a fusion of] advertisement and editorial and which supplements both the adver- tising and editorial columns, illustrating and commenting upon] almost every new thing which is produced in the motion picture] business. Buy the new books of the art as they are brought out by thej publishers; read them and understand them as far as possible. Talk] with everybody you meet in the picture business and add to yourj own knowledge whatever they know. Participate in the "Questions"! columns of the motion picture magazine to which you subscribe; either with questions on the business or with contributions from youi experience. Be alive, whether on or off duty. Then when some good,! live manager needs a good, live operator and searches his memorjfl he will remember YOU. 138 H a '.2 M f 5 H : fe; Hi p o « H SCENE FROM PHOTOPLAY, "THE MINOR CHORD' Courtesy of Independent Mooing Pictures Co., Xew York MOTION HEAD PART II SPECIFIC PROJECTING A\ACHINES Introduction. The progress of the art prevents the presenta- tion, in any one book, of instructions for operating all and every one of the projection machines used or offered for sale. A new detail is added to some standard machine every month, and perhaps an entirely new model is brought out by an old and well-estabhshed manufacturer, or a new manufacturer springs into the arena to fight for a part of the motion-picture trade with a projecting machine entirely new and entirely different in many or all of its mechanical details. To keep up with such development requires at least a monthly review of the new devices and improvements; this is afforded ycu by the trade magazines. To understand the current news of improvements and to be able by reason of that understanding to operate any of the new devices with their peculiarities and special conveniences, the operator should master one machine thoroughly and learn to operate it per- fectly so far as its particular mechanical details go. Then, or be- fore then, he must master the theory of each operating part and regard the part of the projector which effects each function as being a little integral device in itself which may be replaced with an im- proved device designed to effect the same function, the improved device being built into the projector without changing any of the other details of the machine. ^Vhen an operator has attained, a skill with any one machine that will enable him to operate it "with his eyes shut and one hand tied," and when he has added to this physical skill, the mental mas- tery of the separate results to be accomplished by the projector, and has learned how each mechanical detail of his projector is specific to one of these separate results, then it is a matter of minutes, not hours, before he becomes equally skilled with any machine with Copyi-ight, 1911, by American School of Correspondence. 141 66 THE MOTION PICTURE which he is confronted and is able to recognize its defects, its eccen- tricities, its bad adjustments, and its worn parts, and to adjust and replace them and give a good show with improved projection. In some projectors, the feed reel magazine is square, in others it is round; the operator who has skill in placing a full reel of film in a square magazine cannot fail to have the skill to place it in a round one, nor will he forget to close and latch the door, nor forget to feed the end of the film down through the film outlet before closing and latching the door. In every other detail will skill in the operating of one machine lead to the operating of another. A film outlet must hold a film close while passing through; it must have a release device to open the outlet if too close to push the end of the film through easily. The Edison outlet has but one pair of rollers, through which the end of the film is pushed easily. The Power's Cameragraph has a long film outlet with a pair of rollers at the lower end where the film cannot- be pushed through easily, but one of the lower rollers, spring-pressed, is hung with its axle through slots and the ends of the axle project so as to be caught by the fingers, whereby the spring roller may be drawTi back to open the outlet and let the end of the film freely through. The Edengraph and Motiograph use a four-roller trap so built that the rollers at one end are opposite a slot, and the end of the film niay be carried into the rollers through the slot of the outlet. Such small differences in mechanical detail will be all that is to be found in changing from one projector to another. Every pro- jector has its feed reel, its feed reel magazine, its feed magazine film outlet, its upper steady feed, its upper feed loop, its film gate, its intermittent mechanism., its take-up. Every lamp has its four adjustments, as has been discussed and classified heretofore, and so on through the entire list of necessary functional apparatus units. Learn one, learn it well, and watch for the differences when taking charge of a strange machine. In ordering repair parts for any projecting machine, give as much information to identify the machine as it is possible to give. To write to the Nicholas Power Company asking for a complete new intermittent mechanism seems hardly sufficient information. It may be assumed by the company when receiving the order that the mechanism is desired for a Power's Cameragraph, but the inter- 142 MOTION HEAD 67 mittent mechanism for the No. o. Cameragraph is a Geneva, while the intermittent for the No. 6 Cameragraph is a pin-cross move- ment — and which one do you need? Some manufacturers change details or dimensions of parts without changing the number of the machine; for that reason, give the serial number if it can be found. The serial number of the motion head is a number stamped upon the frame somewhere with numbering punches, just as a similar number is placed upon watches, bicycles, and pianos, for identification. Write in this manner: "Please send me for Motiograph, 1010 model, serial number 1263, a framing device connector bar 167 and a crank handle 13^;" The numbers of the parts are taken from the illustrated lists of repairs, if possible to identify them in the printed lists; if not, then the best description possible must be given, or if convenient to do so the worn or broken part may be sent for identification and duplication. Any lack of care in ordering is liable to produce an error in shipment, or to produce a delay by causing the dealer to write, asking for further information in order to enable him to fill the order. In the following pages^ complete instructions are given for a few leading machines, not only for operating them after they are set up, but for setting them up for beginning service. The later paragraphs will not repeat instructions where they are similar to those already given. THE EDISON KINETOSCOPB Installation. First, place the narrow side of the case up; re- move the top cover; and check packing slip. Remove packages in main compartment as follows: adjustable legs, rewind, condensers and lenses, cone and bracket, switch, cover and cords, lower magazines, lamp house with arc lamp, crank and lever inside, upper magazine, long baseboard. The small compart- ment contains the mechanism. The rheostat, completing the out- fit, is shipped in a separate box. Assembling. Place long baseboard. Figs. 37 and 38, on floor, bottom side up, and loosen thumb screws on flanges. Extend leg rods in all tubes and insert in flanges, fastening l)y means of leg clamp screws, adjusting to proper height by clamp screws provided. 143 68 THE MOTION PICTURE 1 Carrying case 2 Base board 3 Base board wing nuts 4 Objective lens on front of cabinet 5 Lamp house 6 Lamp house casting INDEX OF PARTS 23 Hand wheel for lowering and raising lamp 24 Carbon feed lever 25 Lamp body lower binding post 26 Switch binding posts 27 Lamp body upper binding post Fig. 37. Edison Exhibition Kinetoscope 7-8 Lamp house casting guides 28 9 Bolt ajid wing nut 29 10 Rear slide rod 11 Rear slide rod set screw 30 12 Front slide rod 31 13 Front slide rod set screw 32 14 Condensing lens holder 33 15 Condensing lens hood 34 16 Mica lid 35 17 Slide carrier frame 36 18 Condensing lens thumb bolt 37 19 Lamp house door 38 20 Ruby window in lamp house door 39 21 Rear door of lamp house 40 22 Hand wheel for backward and 41 forward adjustment of lamp 42 To rheostat binding posts Switch binding posts for the main circuit wires Film aperture Stereopticon support rod Upper reel Top idler Top sprocket Upper spring idler Film gate LTpper gate idler Film gate tension springs Lower spring idler Lower sprocket Crank Framing device lever 144 I MOTION HEAD 69 INDEX OF PARTS 1 Mica lid 6 Lump house door 2 Condensing lens hood 7 Lamp house lid Fig. 38. Edison Kinetoscope, Underwriters' Model Type "B" 3 Slide carrier frame 8 Hand wheel for lowering and 4 Condensing lens holder raising lamp 5 Ruby window in lamp house door 9 Carbon feed lever / 145 10 Lamp body lower binding post 22 11 Lamp house 23 12 Lamp house baseboard 24 13 Lamp house baseboard guides 25 14 Swi^tch 26 15 Condensing lens thumla Ijolt 27 16 Cone holder casting 17 SUde carrier 28 IS Baseboard chimp casting thumb bolt 29 19 Framing device lever 30 20 Top sprocket 31 21 Top idler 32 70 THE MOTION PICTURE Upper reel Film gate Stereopticon objective lens Stereopticon ring casting Film aperture Position of objective lens on front of mechanism Take-up attachment binding screws Crank Lower sprocket Lower spring idler Rheostat Carefully unpack mechanism and remove mechanism cover by loosening thumb screws. Place mechanism on baseboard, secur- ing it with wing nuts screwed in baseboard. Assemble lower magazine with take-up by removing wing nut on take-up base and clamping long arm over shoulder screws on take-up bracket and base. Tighten center thumb screw directly under mechanism, then place long bolt over take-up sprocket shaft pulley passing it through slot in baseboard, then around small pulley next to magazine, over large pulley on take-up reel shaft, and under second small pulley. Adjust upper magazine and bracket to mechan- ism support by means of the thimib screws already displaced when mechanism was uncovered. One film reel will be found in each magazine. The winding crank, adjusting lever, and stereopticon attach- ment which will be found inside of lamp house, may now be attached to the mechanism in their respective places. Adjust the stereopticon to the left side of the mechanism sup- port by the thumb screw, washer, and wing nut provided. The stereopticon lens and lens holder, which are already as- sembled, may now be placed on the stereopticon slide rod. Screw motion picture lens into position on front of mechanism support through the lens ring and flange already attached to support. Lamp House. Loosen the two small set screws over the round opening provided for slide rods in lamp house bracket. Place the lamp house and lamp house baseboard on this bracket with that side of the lamp house containing a large round opening, toward the 146 MOTION HEAD 71 mechanism. Insert the two shde rods through round openings in bracket, and through shde castings, being sure that the flanged ends of rods are on the stereopticon side of the lamp house. Tighten the two set screws in lamp house bracket above referred to, to hold the rods in position. These rods must not project beyond the edge of the casting where they are fastened with the set screws. Place the rear slide or door of lamp house in position. Cone and Bracket. Place the condensers in cone, and set the same in position, in front of lamp house, fitting it in the round open- ing of lamp house, and passing the cone bracket over the thumb screws which will be found in the casting attached to the front of the lamp house baseboard, then tighten the thumb screw. When plac- ing condensing lenses in cone, be sure that the side of the condenser with threaded ring will be in position next to the arc lamp. Place slide carrier in cone, where provided. Arc Lamp. This will be found packed inside the lamp house; remove, clean interior of lamp house, set the arc lamp in lamp base by placing the stud at bottom of lamp post in the socket in center of lamp base, then tignten round head screw, so that the lamp may not be jarred out of position, when operating. Attach ends of asbestos- covered connecting wires by removing the binding post thumb screws on upper and lower carbon holder bases. The short connecting cord should be attached to the lower carbon holder, and the long con- necting cord to the upper carbon holder. Operation. Carbons. For direct current, the upper carbon should always be the positive pole, while the lower should be the negative pole, and the latter set ^ inch in advance of the former so that a crater will form in a position toward the condensers. With carbons of the same diameter, the positive burns twice as rapidly as the negative, thereby requiring more or less adjusting downward to keep the crater in the optical axis, for this reason some operators prefer a |-inch soft cored upper, or positive, carbon and a ^inch hard carbon in the lower, or negative, carbon holder. This difference in cross-section compensates in the matter of lineal consumption, and the crater is kept in its proper place with less difficulty. The carbons, when burning, should be kept at all times as near to Sg inch apart as possible. -Most satisfactory results are obtained from D. C. when using from 20 to 25 amperes. 147 72 THE MOTION PICTURE ^Yhe^e alternating curroit is used, the carbons should be set in ahgnment, although some operators claim to get better results by placing the lower carbon slightly in advance of the upper. This, however, is a matter of choice, and the careful operator will usually experiment in the adjustment of the lower carbon until he gets it in a position most satisfactory to himself. Both carbons should be soft cored, and kept as nearly as possible to ^ inch apart. They are consumed at about the same rate, the upper carbon about 8 per cent more rapidly than the lower, owing to the upper tendency of the flame. The most satisfactory results are obtained on alternating cur- rent using from 35 to 50 amperes. Fccusi}ig. Adjust the lamp house by means of sliding base on bracket to a distance of 16 inches between lamp house and aperture or picture gate; open film gate on mechanism, and proceed to regidate lamp by using adjusting handle below lamp house hinged door. Slide either backward or forward until you have obtained a white spot r| inches in diameter covering the opening in the picture gate. For vertical adjustment, use upright adjusting handle on the arc lamp post. Adjust the projecting lens so as to have a sharp outline of opening in picture gate on the screen. Stereopticon Lens. Slide the lamp house on the slide rods to the flanged ends. Adjust stereopticon lens in front of the condensed rays, sliding either backward or forward on stereopticon slide rods, until the pi'oper focus is obtained. Adjusting the stereopticon lens in this manner permits of sliding the lamp house from side to side, alter- nating between motion picture objective lens, and stereopticon lens as desired, without rearranging either arc lamp position or lamp house position. Connecting Cords. The free end of the short cord to be attached to a contact on that side of the switch where no open poles are placed. The free end of the long connecting cord attached to the upper carbon holder to be fastened to one binding post in rheostat or transformer. The second long attaching cord to be placed on the second contact of switch where no pole is placed, with the other end attached to the second binding post in rheostat or transformer. Take=up Device. The take-up device comes detached from the head piece mechanism, and is adjusted as follows: Insert the 148 MOTION HEAD 73 left-hand part of the take-up device, Fig. 39, through the hole in the lower part of the cabinet. The hooks 3 on the frame casting of the take-up device hang on the half-inch stud in the lower part of the head piece mechanism. The lugs 4 are fastened into position with two 8-32 machine screws. "\Mien the film has been threaded, as described, and fastened to the spring clip of the core of the take-up reel, and the crank handle is turned, the film will be wound on the reel as fast as it comes through the machine. If the reel does not revolve fast enough, the friction adjusting nut 5 should be screwed in, thus causing the friction wheel 6 to engage friction disk 7, causing the reel to revolve faster and take up all the slack. The lever S is used to disengage the friction wheel from the friction disk and is only used when the film is rewound from the take-up reel to the top reel. AMien the film is rewinding, this lever should be thrown back toward the reel. At all other ng. 39. Take-Up Device INDEX OF PARTS 1 Lower sprocket 2 Lower idler pulley 3 Take-up frame hooks 4 Take-up frame lugs 5 Take-up friction adjusting nut 9 10 Take-up friction wheel Take-up friction disk Disengaging lever Momentum friction spring Crown gear times the Handle of the lever should point outward. When the film is rewinding, use the friction spring 9, to check its momentum if it turns too fast. This is accomplished by pressing down the spring until the end rubs against the inside of the crown gear 10. This spring is only used when the film is rewinding. At all other times it should stand in position as indicated on Fig. 39. Wiring. The binding post 10, Fig. 40, on the lamp connects by short wire with switch binding post, and the lamp binding post 11 connects by long wire with rheostat binding post. The interior of the lamp house is planned for all lights known to exliibitors, including the electric arc light, for botli alternating 149 74 THE MOTION PICTURE and direct current, tlie oxy-hydrogen (or calcium) burner, the Edison gaso-oxygen burner, or the methyl-etho saturator. Assuming now that we are. assembUng the electric burner, observe the following rules, and refer to Fig. 40. The lamp base 1 is assembled ia the lamp house. Place lamp post S in socket 4 and tighten with binding screw. Next place carbon in carbon holders I4 and tighten car- bons with thumb screws 9. .The lamp being now in the lamp house, is ready to receive the wires 12. The main line should be wared for 110 volts direct current, or 52 or 104 volts alternating current, 25 to 40 amperes, using a standard 30-ampere cut-out, or combination switch and fuse block with 40-ampere fuses. If alternating current, 60-ampere fuse may be used. \Mien the wires 12 are connected, the carbons are brought together by raising the feed lever 8 to make the arc. ^'^" Oxygeu Ligu'*' ^^°' After closiug the circuit through the car- INDEX OF PARTS J Arc lamp base 9 2 Hand wheel for forward and 10 backward adjustment 11 3 Lamp post 12 4 Lamp post base socket 13 5 Hand wlieel for lowering and raising 14 6 Lamp post friction screw A. 7 Lamp body D. 8 Carbon feed lever Carbon holder thumb screws Lamp body lower binding post Lamp body upper binding post Wires Raising and lowering lever fric- tion screw Carbon holders Socket for alternating current Socket for direct cvuTent bons, they should be separated about \ inch to make a perfect arc. This is done by lowering the feed lever slightly. A perfect circle of white light should cover the aperture 30, Figs. 37 or 38. All this is done before the film is threaded into the mechanism. Should the circle of light on the aperture be imperfect, it may be remedied by either or all of the following adjustments: 150 MOTION HEAD - 75 By swinging the lamp either to the left or right (revolving on the lamp pest), using the hand wheel ^, J'ig. 40, as a lever; or hy raising or lowering the lamp by turning hand wheel 5, or by a forward and back adjustment by hand wheel 2. The size of the circle light cover- ing the aperture can be increased or diminished by sliding the lamp backward or forward. If a "ghost," or dark spot, appears in the middle of the screen, this can be remedied by sliding the entire lamp house backward or forward on the large baseboard. The set screw and tension device 6 is placed on the lamp for the purpose of giving an amount of friction necessary to prevent the lamp from dropping on the post from its own weight. This set screw should be snugly tight, but not tight enough to bind. The set screw 13 is for tightening the friction bushing on shaft of handle 5. This also prevents the lamp from dropping from its owti weight. This, how- ever, should not be too tight. Six Edison Rules. First. Adjust the height by raising or lower- ing the lamp on the lamp post 3 by the hand wheel 5, Fig. 40, until the points of the carbons, when brought together, are opposite the center of the condensing lens. Second. Turn on the current by closing knife switch. Lift up mica lid 16, Fig. 37. The revolving mica shutter behind the fram- ing plate should be turned so as to leave the space between the fram- ing plate and the objective lens entirely clear. This should be done before the film is placed in the machine. Th ird. The lamp should then 1 )e adjusted by moving backward or forward until a bright, clear, round light just covers the s(|uare hole in the framing plate. If the circle of light is too large, light is lost and the brightness of the picture is impaired. ^Mien properly adjusted, the light on the screen will be bright and free from color. Fourth. The operator should adjust the objective lens by turn- ing the focusing screw, until the square on the screen is sharply de- fined. Only a slight adjustment is then required to sharpen the pic- ture when projected. Fifth. All this should be done before the film is threaded up. Sixth. Never turn the light on the film until it is in motion, and if by accident or mistake the film should stop while the light is on, shut mica lid 16, Fig. 37, at once, or the film will catch fire. 151 76 • THE MOTION PICTURE Calcium or Qaso=Oxygen Light. \Mien calcium or gaso-oxygen light is used by tlie operator, tlie arc lamp base 1, Fig. 40, remains in position on the floor of the lamp house. Into the socket^ is inserted the eccentric holder post, with which every complete projecting kinetoscope is equipped. The post must not be clamped too tightly; it must be loose enough to permit the eccentric holder to move to right or left and forward or back, as may be necessary in centering the light on the condenser. The clamp screw may be tightened after the center is found. Directions for Operaiing. Remove jet from lantern to place lime pencil in straight position into lime cup "within \ inch from point of jet. Turn on the hydrogen gas (black cylinder) first until the flame becomes the size of a light from an ordinary gas burner. Then turn the oxygen gas (red cylinder) slowly until the light gets bright and dazzling. Too much oxygen dulls the light and may extinguish it; yellowish flames of hydrogen should always be noticed around the lime pencil. If not intense enough, add small portions of the gases initil the light is nearly hissing. Turn off oxygen first and then hydrogen. Tuni lime pencil about every few minutes, to prevent cracking of condensers and see that no draft strikes the lanterii. If light snaps out, shut off both gases and re-light as above stated. Observe rules 3, 4, 5, and 6 above. The gaso-oxygen saturator and burner are especially adapted for traveling exhibition purposes, and also for home use. A com- plete description of the gaso-oxygen outfit, together with directions for generating the gas and adjusting the burner, will be found under the heading "Directions for Operating the Gaso-Oxygen Light." Rules 3, 4, 5 and 6, above, must be carefully observed. Threading up the Film. The film is wound on the upper reel 32, Fig. 37, by placing the end in the spring clip on the core of the reel. The emulsion side, that is, the gelatine side, should be in. \Mien the reel is full, the end of the film is brought under the lower front side of the reel. It passes over top idler 33, under top sprocket 34, over the upper spring idler 35. Now open film gate 3G. Engage the film on the intermittent or mitldle sprocket (not 152 MOTION HEAD 77 shown in cut), leaving about 3V inches of the fihn slack. The gate is then closed and secured by latch, thus forcing the slack film into a loop, the lower part of which passes behind the upper gate idler 37, as shown. The film is now between the framing plate and the film gate 36. As it passes the aperture 30 the film is held against the framing plate by the springs 38. This checks the momentum of the film and prevents the center of film from touching the gate, thus avoiding possibility of scratching. A second loop is then formed. This is kno^^^l as the lower loop and should be about 2 inches in length. This is formed by passing the film under the lower take-up sprocket and over the grooved idler spring pulley, which is closed against the film to hold it firmly against the lower sprocket. Having then formed both loops, and the picture sitting squarely between the tension springs 38 and grooved framing plate, the film is next passed over the hard rubber roller, which will be found immediately in front of the lower take-up sprocket. The end of film is then passed under the core of the take-up reel and secured by the steel clip on the core. The machine is then ready to be set in motion, which is done by turning the crank 4^ away from the operator. The framing lever 4- should be adjusted with set screws bearing on the flat surfaces of the lever. The picture is then framed upon the screen by lowering or raising the lever. The emulsion side of the film should be always toward the light and the picture should show in the aperture upside down. Framing Device. As has been noted there is no setting or adjust- ing of the film as it passes o^•er the frame plate. This is rendered unnecessary by the framing device. After the picture appears on the screen, if it is not framed exactly, it is very easily accomplished by raising or lowering the lever 4^ until the proper effect is obtained. Adjustable Rheostat. After the rheostat is placed in circuit as described under the heading "AViring," the current may be regu- lated by raising or lowering the contact spring. Before turning on light, the contact spring should be set at the bottom of the rheostat so as to prevent too much current being drawn suddenly, and burn- ing out fuses. If, after lighting the lamp, the light is not strong enough, raise the contact spring until the desired strength is obtained. General Instructions. The intermittent sprocket shaft is pro- vided with bronze eccentric bushings, and set screws are placed in 153 78 THE MOTION PICTURE the cast frame to hold these bushings secure. The idea of making the bushings eccentric is to permit the operator to adjust them so that the star wheel and cam fit perfectly, thus avoiding unsteady pictures. If vou wish to show steady pictures upon the screen at all times, it is necessary to look carefully to the adjustment of these eccentric bushings, and when these eccentric bushings, or the star wheel or cam, or the intermittent sprocket become worn, it is highly essential to good results that they be replaced at once. See that all set screws are kept tight, and the machine well oiled, so that it A\ill run smoothly and regularly at all times. Be care- ful not to use too much oil, as surplus oil is liable to spatter on the film and damage it. Films should be handled carefully and kept clean and free from dust. They should be wound on reels when not in use, and placed in a dust-proof reel box, and if possible kept in a cool, dry place. The films should be kept in perfect condition, any broken places being mended at once. Film Winder. This ingenious little apparatus, Fig. 41, is a great labor- saver. It is small and compact and can be placed on any table or shelf that may be near the projecting machine, being provided with thumb screws for instantly adjusting it to a table. If a Kinetoscope is not equipped with a take-up reel, this film winder is an absolute necessity. After the film has been run through the projecting macliine the end is placed in the groove of the winding shaft with the emulsion side in; and by turning the crank of the winder slowly, a 100-foot film can be properly wound in less than ten seconds of time. There is an attachment on the winder for removing the film from the shaft after it has been wound, in perfect safety and in a perfect roll. This attachment consists of a nickel-plated disk of about the diameter of a l')0-foot film when rolled up. This disk slides from Fig. 41. Film Winder 154 MOTION HEAD 79 front to back of the shaft. After the film is wound, the exhibitor sHdes the disk from back to front carrying the roll of film with it, thus freeing it from the shaft. Edison Film Mender. First open all gates. Place one end of the film on left-hand side of repairer, emulsion side up, with the bottom line of picture as near the center of the glass as possible, then close and clamp left-hand gate over the film. Place the widest part of the gauge, which forms part of the repairing outfit, against the closed gate, and, holding it firmly on the film, take a sharp knife and cut off that portion of the film which projects beyond the gauge. Next, reverse the gauge, place it with the narrowest part over the film and close against the locked gate, moistening that portion of the film which projects beyond the gauge, and sci^ape off the emul- sion. For this use a moderately sharp knife. Be careful not to scratch away the celluloid. After this is done, open the gate and move back the film so that it will be entirely covered by the gate, and re-lock the gate. Next take the other end of the film, place it on the right-hand end of the repairer in the same manner as was done before, with the picture line as near the center of the glass as possible. Use the gauge in the same manner as before, that is, use the widest side and cut off that portion of the film which projects. This end of the film should not be moistened, nor shoidd the emulsion be scraped away. After this is done, release the left-hand gate and place that end of the film in the same position as it was after the first operation had been performed. You will then note that the ends will overlap about ^ of an inch. Moisten both ends of the film with the film cement where they overlap, cement the two ends together carefully and smoothly (the one with the emulsion scraped off underneath), close dowTi the center door or gate and lock same securely. Leave the film in this position for from 20 to 30 seconds, when same will be thoroughly cemented together. \Mien about to take the film from the repairer, open the center gate first and if the film is found to adhere to same, by working same carefully to the right and left the film will be released from the gate without breaking the joint. Operating Qaso=Oxygen Light. The gaso-oxygen light is the 155 80 THE MOTION PICTURE result of a series of exliaustive experiments, and it is offered fre- quently as a substitute for the methjl-etho light outfit, for the reason that it is strong, simple, and cheap to operate. The operation of the light is very simple, and in order to make it perfectly clear, the directions are given under three different headings, as follows: (1) the chemicals; (2) the oxygen generator; (3) the gaso-oxygen satura- tor and burner. Necessary Chemicals. The necessary chemicals can be obtained in almost any large town if the original supply becomes ex- hausted. Buy the chemicals from a reliable druggist, and see that there are no chips or other combustibles mixed with the chlorate of potash or the black manganese. The following chemicals will suffice for two hours continuous running: 2 lbs. chlorate of potash, and ^ lb. black manganese (in the retort 1, Fig. 42), \\ pints 90 deg. gasoline (in the saturator), and 1 Hme pencil. Mix 4 parts of chlorate of potash and 1 part of black manganese thoroughly and distribute it equally along the entire length of the retort 1 . Turn the retort so that the seam comes on top. FOR GENERATING OXYGEN GAS INTO GAS BAG ONLY 1 1 Russia iron retort and cleaner 3i X18 2 1 Retort stand 3 1 Burner (gas or spirit) 4 16-inch lined tubing from retort to purifier 5 2 Purifiers, complete with rubljer stoppers, glass and metal tubes 6-ft. rubber tubing | X 3-16 con- necting purifiers to gas bag 1 55-gal. gas bag, stopcocks and regulator 5-ft. rubber tubing i Xi from gas bag to light FOR GENERATING AND COMPRESSING OXYGEN GAS 1 1 Russia iron retort and cleaner, 7 3^X18 2 1 Retort stand 8 3 1 Burner (gas or spirit) 4 16-inch lined tubing from retort 9 to purifier 10 D 2 Purifiers complete, with rubber stoppers, glass and metal tubes 1 1 G 6-ft. rubber tubing |X3-16 con- necting purifiers and gas bag 12 1 55-gal. gas bag and double stopcock. 5-ft. rubber tubing | X3-16 from gas bag to pump. 1 Compressor 5-ft. lined tubing and couplings from compressor to cylinder 1 gauge attachment, regulator and 5-ft. tubing to light 1 25-ft. cylinder and key 156 MOTION HEAD 81 Fill the retort 1 as above. Connect the purifiers 5 as shown in Fig. 42. The purifiers should be half filled with pure water and \ ounce of caustic soda placed in bottle nearest the retort. Be careful that the ends of tubes AA are helow the surface of the water and the ends of tubes BB, above the water. The gas bag 7 should be rolled before connecting, to eject all air. Place the burner 3 on retort stand 2 at one end of the retort 1. Gas will generate as soon as heat is applied. Allow a little oxygen to be given off, before finally connecting the retort 1 with the tubing 4 to the first purifier 5. To ascertain when the gas is pure, light Fig. 42. Oxygen Generator a piece of bro^vn paper, thoi blow it out, and hold the smoldering portion in front of the arm of the retort 1. AMien the gas is pure, the paper will burst into flame; then connect with tube 4 ^-^id see that all the tubes are straight. Now open the tap of the gas bag 7. Scores of people forget to do this. The gas bag 7 is now filling with pure oxygen gas. INIove the burner 3 along under the retort 1 inch by inch until the chemicals are exliausted. As soon as the bag is quite full, turn off the tap at gas bag, remove the burner from the retort, and disconnect the tubing. AMien using the gas bag a pressure of 150 to 200 pounds is re- quired to procure the best results, which is obtained by means of press boards and weights. The capacity of the gas bag is 55 gallons, and about 2 pounds of chemicals must be used to fill it completely. The gas bag should be kept in a warm place when not in use. 157 S2 THE MOTION PICTURE Wash out the retort with hot water as soon as possible, and do not attempt to pick out the baked residue with a chisel or other sharp instrument, as this spoils the retort. Don't leave mixture to harden ; unless the retort is cleaned at once, it is almost impossible to remove the hardened residue. ^^^len the high-pressure method is used, the oxygen gas is com- pressed into cylinder 12 with the compressor 9 until about 100 pounds pressure is reached in cylinder 12. Gaso=Oxygen Saturator and Burner, The gauge attachment, Fig. 43, is supplied with two needle valves; turn on first the one lead- ing to the saturator, see that valves C and D are also open, and light the jet, then turn on the oxygen from valve B, and regulate your light in the same manner as oxy-hydrogen gas is used, until Kig. 43. Gaso-Oxygen Saturator and Burner the light is bright and dazzling. Too much oxygen dulls the light, and may extinguish it. Little red flames should always be noticed around the light, to show that sufl^cient gasoline or ether is supplied. If the light is not intense enough, add small portions of the gases until the light is nearly hissing. Always turn on the gasoline first when lighting, and when through, turn off the oxygen first. Have the lime pencil properly adjusted about f inch above the point of the jet when starting, and turn the pencil upward about every five minutes, to prevent the flame from burning through the pencil and striking back against the condenser, as this will crack it. See that no draft strikes the lantern, thereby causing the condenser to break. Should the light snap out, it is a sign that too much oxygen is used, then both gases must be turned off, and relighted as above directed. 158 MOTION HEAD 83 Fig. 44. Automatic Shuttet for Underwriters' Model of Edison Kinetoscope It is imperative that 90-degree gasoline only is used, as lower grades will not evaporate quickly enough to give sufficient supply of lighting material. In changing the fluid from gasoline to ether, it is necessary to open the saturator, take out the cotton, and have it thoroughly cleaned, by exposing it to the air until it is perfectly dry. Note the following differences over the other saturators: Ninety-degree Gasoline or Sulphuric Ether can be used with utmost and absolute safetj', as there is no direct connection between fluid and flame and consequentlj^ no danger. Any number of lights can be run from one saturator, and any single or dissolving lantern jet, or dissolving key can be adapted. The 1,000 candle-power jets give the same light with gasoline saturator, as with oxy-hj'drogen gases. The saturator is equipped with needle valves and regulators, guaranteed air tight. If no cylinder is used, and the oxygen gas is supplied direct from the gas bag, it is necessary to use a stand with two-way connections near the saturator to regulate the gases conveniently, in the same manner as above described. Automatic Shutter. On Under- writers' Model. Under no possible condi- tions can the light be thrown upon the film except when the film is in motion. Wlien the shutter, Fig. 44, is wide open it automatically locks so that no power is required to keep it open, eliminating undue wear on the gearing and causing easier operation of mechanism. \Mien the speed of the machine falls below a certain point, however, it automatically unlocks and closes. On Exhibition Model. This very simple but effective device automatically shuts off the light when the film is at rest, and absolutely prevents the light being thrown upon the film except when the latter is in full motion. Fig. 45 Automatic Shutter for Exhibition Model of Edison Kinetoscope 159 84 THE MOTION PICTURE This shutter, Fig. 45, consists essentially of two parts: a film gate, upon which is mounted a metallic shutter and centrifugal gov- ernor, and a casting upon which is mounted an intermediate gearing, through wliich the shutter is connected to and operated by the large driving gear. The exliibition automatic shutter is not regularly furnished with the improved exhibition model machine, but is attached, at an extra charge, when ordering a machine. Rheostats. The question of rheostats is one about which there has been much discussion and diversity of opinion, due principally to a lack of knowledge of real conditions. *It is not practical to make what might be termed a "universal rheostat" or one equally well adapted to meet all conditions. A rheostat with a capacity of 25 to 40 amperes on direct-current circuits of 100-125 volts will give perfectly satisfactory results under ordinary B-* conditions in the hands of an intelligent ^^ operator. To get equally satisfactory re- 'S^B suits with alternating current, 35 to 60 am- ■fl peres are required with the same line volt- ^H age. For direct-current circuits of 100-125 |H volts, the Underwriters' INIodel (coil type) ^B rheostat is recommended, and the Under- Ml writers' Model (type "B") for altemating- •^^ current circuits, on account of its greater ■^ capacity. The latter will give equally satis- Fig. 46 Coil Type Rheostat factory rcsults ou both direct- and alter- nating-current circuits of 100-125 volts, hut on direct-current circuits care should he taken to adjust it so that not more than 25 to 40 amperes are consumed in the line. The coil type rheostat. Fig. 46, is regularly furnished with the exliibition model projecting Kinetoscope, while the new grid type, Fig. 47, is supplied with the Underwriters' Model machine. In the design and construction of the grid t}'pe rheostat the old- style wire resistance coils have been discarded and replaced with cast metal grids, supported and insulated by water and fireproof material. The rheostat can be used on either direct or alternating current of any frequency, with equally good results, and in either case a max- 160 f MOTION HEAD 85 imum current can be obtained without excessive heating on a line voltage varying from 100 to 125 volts. The front, back, and sides are enclosed with solid sheet metal, while the top and bottom are enclosed with perforated sheet metal. The operating switch, switch contacts, and binding posts are all ^ — jvjol inside the sheet metal frame and are ' '"' thoroughly protected from outside ^ , . rrn 'ill, 11 • i. • 1 Fig- 47. Grid Type Rheostat contact, i he switch handle is outside the sheet metal case and a pointer indicates the position of the switch. TABLE I Projection with Edison Lenses Project a picture 3 ft. wide for every 10 feet of dis- tance. No. 1 M. P. Lens No. 4 " " No. lA Stereo. Lens No. L\A " " No. 2 M. P. Lens No. 5 " " Xo. 2A Stereo Lens No. 3 M. P. Lens No. 6 " " No. 3 A Stereo. Lens Project a picture 3 ft. wide for every 13 feet of dis- tance. Project a picture 3 ft. wide for every 19 feet of dis- tance. THE MOTIOGRAPH How to Install or Set Up the Motiograph. The complete ma- chine and equipment Fig. 48, comes packed in a single case. Take out all the parts and see that all are wiped free from dust and that none are left in the packing case or overlooked in the packing ma- terial. The mechanism base, lamp house, sliding frame, backward and forward slide rods and brackets are screwed to the baseboard. The arc lamp, saddle, post, etc., will be found inside the lamp house. ^Mien the pedestal base is used to support the Motiograph it should be fastened very firmly to the floor with f-inch lag screws, large square head wood screws, of good size, and care should be taken to see that as nearly as po.ssibIe contact with the floor is had on all sides. In order to do this, as a rule, it is advisable to use wedges 161 86 THE IVIOTIQN PICTURE of hard wood. It will be well to screw the base tightly to the floor and then drive the wedges just tight enough at different points so the base will rest with equal pressure on all sides. To assemble the equipment set the lamp house in position on the lamp house slide frame, and insert the two cross slide rods through Fig. 48. Details of Motiograph the ears on both the lamp-house base and the sliding frame, screw- end first, and screw them into the ears in the sliding frame that comes next to the operator, which is the right side when looking from the rear toward the front of the instrument. Set the Motiograph mech- ani.'-m on the circular swivel base 2 and screw down the swivel thumb wheel. (Cut above shows the 1908 and 1909 Models with 162 MOTION HEAD 87 thumb wheel 12 on top of the base. The thumb wheel for the 1910 Model is larger and is under the base.) Attach the upper reel arm 7 A by entering the shaft and cross pin into the rewind vertical socket arbor, and screw into place with the three reel arm thumb screws 128. Attach the take-up or lower reel arm 9A, Fig. 49, with the three reel-arm thumb screws 237. Place the take-up belt in posi- tion on the take-up pulleys with the idler pulley under the belt, first having loosened the tension screw of the belt idler 109 until the belt is quite loose. Remove the objective lens from the litde pasteboard box and screw it into position on the front plate of the mechanism, first having removed with a soft cotton handkerchief any dust that may have ac- cumulated on either the front or rear surface of the lens. Be sure that the extension collar is in place, if the lens is of such focus that it requires one. Otherwise the lens can be brought to the focal point. Place the framing lever han- dle 75 in the framing lever socket 11, and screw it into place. Loosen the little thumb screw on the crank 13 A, place the crank in position on the crank arbor and tighten the little thumb screw on the crank so it engages with the groove in the crank arbor to hold the crank in place. Remove the stereopticon lens bracket screw and attach the stereopticon lens bracket 37. Attach the stereopticon lens ring to slide rod on stereopticon lens bracket, tightening into place widi the thumb screw. Remove the stereopticon lens from its box, care- fully wipe from the surface of the lens any dust that may have ac- cumulated, remove the flange ring from the lens. Insert it back of the lens ring with the bead or rim to the front; insert the lens and screw it in place. It is unnecessary to have the flange ring at- tached to the cast ring or to have the cast ring threaded. The location of the stereopticon objective lens on the rod support should be such that the distance from about the center of the lens Fig. 49. Take-Up Device 163 88 THE MOTION PICTURE (from front to back) and the front surface of the front condensing lens is equal to the focal length of the lens. For example, a stereop- ticon lens of 122^-inch focus should be located so that the distance from the middle of the stereopticon objective lens to the front of the condensing lens is about 12 inches when the rack adjustment of the lens is so set that it will allow of liberal adjustment in either direction. The stereopticon lens bracket rod may be screwed into either the front or the rear of the bracket depending on the focal length of the lens. The universal reel clamp is used for the 1908 and 1909 Models No. 1 and No. 2 machines It will be found clamped on the reel arbor. This should be removed by holding the clamp with one thumb and finger and loosening the thumb screw with the other. This will loosen the clamp and it may be slipped off the arbor. Now put the reels in place on the arbor, and turn around until the key pin on the arbor enters the seat (hole or keyway) in the reel. Slip on the universal clamp with the projecting pin next to the reel, insert the pin into the ke}'way or slot in the core block of the reel, and tighten the clamp thumb nut, which will hold the reel se- curely on the arbor. The vmiversal reel clamp has been dispensed with for the ]Model No. lA for 1910 and a new arrangement called a jointed red shaft latch is used. AMien fireproof magazines are to be used, they should be at- tached before the reels are put in place. To attach the fireproof magazines unscrew the two thumb screws in the magazine spiders £6, so as to let their points pass the flange on the reel arm, put the magazine in place on the reel arm by inserting the boss on the reel arm into the opening of the spider. Have the fire trap or valve toward the upper or lower feeding sprocket (depending on which of the reel arms you are assembling), tighten the thumb screws to engage the flange on the reel arm. Now, open the magazine and attach the reel in the same manner as in instructions previously given. The magazines are marked on the inside "upper" or "lower." The condensing lenses are mounted in a nickel-plated mount and are held in by the use of two inside telescopic bands. The con- denser mount is held in position on the front of the lamp house by two clamps and two screws. The mount may be removed from the I lamp house front, for changing or cleaning the lenses, by turning the 164 MOTION HEAD 'dd two clamps until the flattened sides of the clamps come next to the flange of the condenser mount. The mount is usually left attached to the lamp house for shipment. The flat side of the condensers should always be outward and the convex sides toward each other. The surfaces of the condensing lenses should be free from dust, per- spiration, or other accumulations to insure the unobstructed pas- sage of the light. The No. lA 1910 framing device, Fig. 50, can be used in the 1909 No. 1 or No 2 mechanisms by buying the short connecting link 107A to connect the framing handle with the framing device, and the 1909 framing device, Fig. 51, may be used in the 1910 machine by using the 1909 link 167. Both framing devices are practically alike with the exception of the vertical casting, which can be interchanged Fig. 50. Motiograph lA 1910 Model Framing Device between the two, and the change can be made from one to the other by removing the four screws in the side. Attach the stereopticon slide carrier to the lamp-house slide carrier swing 310, and clamp in position with the thuml) screw on top of the carrier swing. If the lamp house cone 377 has been re- moved for convenience in packing for transit, it is to be attached by inserting the two dowel pins in lamp-house support 306 and will be held in place by the two small thumb screws on the side of the cone support. Test the slide on the lamp house and see that it slides freely on the backward and forward and the sidewise movements. The proper adjustment for the lamp house on the backward and forward sHde should be a point where the distance between the 165 90 THE MOTION PICTURE front face of the condensing lenses and the film on mechanism will be about 12t inches when operating at a distance of about 60 feet from the screen with a picture of moderate size. AMien operating a greater distance from the screen, the distance between the conden- sing lenses and the aperture plate should be greater, depending on the length of focus of the condensing and objective lenses that are being used and the individual preference of the operator. Some operators prefer a greater distance between condensers and film, even when operating at the above distance from the screen. 6 ZIS k 'tff^r^'^. ^:)^ -ZiS'' Fig. 51. Motiograph No. 2, 1908 and 1909 Framing Device Motiograph Lens Adjustment. The lens should give a sharp focus on the screen giving clear detail. If the lens does not give a sharp focus after turning the focusing ring to both extremes of ad- justment, it will be an indication that the extension collar used is either too long or not long enough, in which case test may be made by unscrewing the lens from the collar and holding it by the hand, shift- ing to different distances from the film to determine what position is necessary to give a sharp focus. The use of mica with scratches on it for the test focusing is recommended. Open the film gate, swing it to the left, tuni the crank of the mo- tion-picture machine so the leaves of the shutter do not cover the opening in the aperture plate, so as to allow a free passage for the light through the aperture plate and the objective lens. This should be done before the film is placed in the machine. 166 MOTION HEAD 91 The objective lens on the front of the motion-picture machine should now be focused by turning the focusing ring until the square of light on the screen is sharply defined; that is, the margin of the light opening should be clean and sharp and not fuzzy. \Mien this is done only a slight adjustment is recjuired to focus the picture sharply when the film is in place. All of the above adjustments should be accompHshed before the film is placed on the machine. Some operators use a piece of mica on which some sharp scratches have been made with a knife, for the purpose of getting a sharp focus before the film is put in place. A piece of ruled mica is furnished with each Motiograph. WTien using the Motiograph equipped with the automatic fire shutter, it will be necessary to open the film gate when doing the pre- liminary focusing of the objective lens, and to see that the illumina- tion on the screen shows a clear outline of the margin of the aperture plate. Position of Crank of Motiograph When Showing Pictures Fig. 52. Position of Crank of Motio- graph When Rewinding Films Threading the Film. ^^Tlen film is received from the manu- facturers wound in a roll, the center of which is too small to admit the core block of the reel^ it is necessary to rewand it. This may be done by removing the lower reel from the arbor, place the roll of film on the bare arbor, insert the outer end of the film under the spring clip on the core block of the upper reel, and wind the film on the upper reel. To shift the connection between the crank and the reel arbor when using the :Model No. 1 for 1909 or No. lA for 1910, all that is necessary is to press a spring plunger at the right of the crank boss of the main frame. Fig. 52, turn the crank slightly, pull it toward you about y\ of an inch, and the spring bolt will automatically drop 167 92 THE MOTION PICTURE into the other groove and hold the crank in place for rewinding the film, Fig. 53. After the film has been wound on the upper reel, remove the upper reel and place it on the take-up below. Place another reel on the upper reel arm, take the outer end of the film (which was on the inside of the roll when received), pass it to the rear of the upper reel, inserting the end under the spring clip^ and again wind the film on the top reel, making sure that the emulsion or dull side of the film is wound toward the outside. ^\Tien the film has been wound back on the upper reel, press the spring plunger and return the crank to its normal position. \^^len using this form of reeling mechanism in combination with fireproof film magazines, it is unnecessary to remove either the magazines or the reels for re- winding; in fact, with reasonable care and by the use of a few feet of white undeveloped film on each end of the picture film as leaders, the operator will see that the film is nearing the end, and it can be run and rewound time after time and it will not be necessary to disconnect the film from either reel until the film is to be changed for a different subject. Draw from the reel a length of about 2 feet of film, press the handle of the upper sprocket roller bracket 2If. to the left as far as it will go, pass the film under the sprocket wheel, so that the teeth of the wheel engage in the perforations of the film, and press the top of the roller bracket to the right until the roller comes into place against the sprocket wheel and holds the film in place. The roller brackets should not press tightly against the film, and there should be just room enough between the roller and the sprocket wheel for the film to pass without being pressed. The adjustment of these rollers is accomplished with the screw 203 and check nut. This Motiograph Rewinding 168 MOTION HEAD 93 adjustment is always properly set before the machines leave the factory, and should not require any further attention until the rollers have become somewhat woni, unless some one tampers with the machine. However, it is well to keep this adjustment in mind. Press the film gate latch 154 to open the gate, swing the gate back, raise the intermittent sprocket roller bracket 23 until it stands in a horizontal position, lay the film on the aperture plate in such a position as to leave a loop at the top, as indicated by the word "loop," and return the intermittent roller bracket to its original position, to hold the film in place on the sprocket teeth of the inter- mittent sprocket. The intermittent roller bracket has a screw adjustment the same as those of the upper and lower roller brackets, except that it has a check screw instead of a check nut to hold the adjustment. Press downward on the handle of the lower roller bracket, pass the film over the lower feeding sprocket wheel, leaving a loop between the intermittent and the feeding sprocket as indicated by the word "loop" in Fig. 48. See that the teeth engage the sprocket holes in the film and turn the roller bracket to place. Pass the loose end of the film over the core block of the lower take-up reel and under the end of "the spring clip. A\Tien threading the film, place the framing lever about the mid- dle of the two extremes of its up and down movement, for by so doing the upper and lower loops may be properly proportioned so as not to require rearrangement. Turn the handle of the machine over to the right toward the front of the machine at the rate of about one revolution per second. The exact speed at wliich the handle should be turned will readily be determined by the movements of the figures in the pictures, which should be normal and natural, and by the flicker, which must not be too great. \Miile the machine is in motion test both bottom and top loop to see that they are sufficiently long. Take hold of the framing lever handle 75, swing it up and dowai (while the machine is in motion only) as far as it will go, and when at the two extreme positions there should still be a small loop remaining. If the loop is entirely taken up, the roller bracket should be opened and the loop extended suf- ficientlv. If this is not done the film may be torn. You are now 169 94 THE MOTION PICTURE ready to start. The loops should not be too long as they have a tendency to vibrate considerably, which may make the pictures unsteady. It is important when rimning new film to scrape off the spots of film emulsion that collect on the film tension springs and the ribs of the aperture plate. These accumulations, if allowed to remain, have a tendency to not only scratch the film, but make it run unsteady, and are liable to be the cause of slightly tearing the corners of the sprocket holes in the film, besides making the machine run heavy, with increased wear to the parts. A silver dime is a good instru- ment to use for scraping them. On the first run film, the tension springs should be scraped before starting to make each run of a thousand feet. Do not scrape the springs with a knife or other steel instrument, as it would be liable to leave a rough surface on the ten- sion parts that would injure the film. Instructions. To remove the front of the Motiograph loosen the two thumb screws at the bottom, lift up the spring at the top while pulling the front plate forward sufficiently to disengage the spring, and lift it up to disengage it from the thumb screws below. Adjustments. There are four important adjustments in the Motiograph that it will be necessary for the operator to concern himself with. (1) The adjustment of the idler on the take-up belt should be just tight enough to make sure that the film will be wound up on the reel as fast as it comes through the machine. If too tight it will pull too hard on the film, with the result that it is liable to tear the sprocket holes. The flexible broad flat belt, in combination with the adjustable idler, furnishes a most sensitive, yet positive, means of taking up the film without doing injury to it. When the idler is adjusted, the check nut on the screw should always be tightened so as to retain the adjustment. If the belt is too tight when the tension is oft", stretch it by pressing the two sides together near the large pulley. (2) The adjustment of the sprocket rollers or idlers should be given careful attention. There should be just room enough for the film to pass freely between the roller and the sprocket without pres- sure on the film. The film rollers are adjusted to position by a set screw that passes through the roller bracket. After the screw is 170 SI MOTION HEAD 95 properly adjusted the check nut or check screw, as the case may be, should be tightened so as to retain the adjustment. (3) The Geneva movement that operates the intermittent film sprocket wheel, called the star and cam, will need to be adjusted only after it is worn to such an extent that the intermittent sprocket wheel can be slightly turned when at rest; that is, when the pin in the Geneva driver or pin wheel is on the opposite side of the pin wheel from the star wheel. The adjustment is accomplished by the two set screws that clamp the eccentric bushing in position. To set the Geneva parts closer together, loosen the lower set screw very slightly and tighten the upper screw. Have the adjustment of the Geneva driver, cam, or pin wheel just close enough to the star wheel Fig. 54. Motiograph Safety Shutter that, the movement of the pin wheel shaft will be free and easy, yet so there will be no circular movement to the intermittent sprocket wheel while it is at rest. Do not tighten so the cam or pin wheel will not work perfectly freely. The governor that operates the fireproof shutter may be removed from the Motiograph if necessary by removing the bushings at each end of the governor shaft or arbor, or by removing the gear bridge and the inside bushing. The bushings are held in place by set screws. (4) The adjustment of the governor and fireproof shutter, Fig. 54, is accomplished by sliding endwise the pivot bushings in the frame. To adjust, loosen the screws that hold both bushings, hold the two between the thumb and finger and slide them slightly out and in when the machine is running at regular speed, until the point is reached where the fireproof shutter will be raised clear up, and at the same time, the little bar which connects the shutter with the governor crank bar will rest loosely on the governor crank pivot. 171 96 THE MOTION PICTURE In no instance should it be drawn tight. Now tighten the screw on the inside bushing, then loosen the outside bushing just enough so the governor will work freely, and tighten the screw on that bushing. Don't adjust the governor too tight; if too tight, the machine will run hard and, besides, the wear will be excessive. Oiling. It is absolutely necessary that a motion-picture machine be kept well oiled, in order to keep it in good condition, and that it may do good work. Remember that while in operation the bal- ance wheel shaft and Geneva action, which operates the intermittent sprocket, is making nearly 1,200 revolutions per minute, or 72,000 revolutions per hour, and that when giving fifteen shows per day, of twenty minutes each, the balance wheel and Geneva action has made 360,000 revolutions. No machine can be expected to endure such work without proper care. Be sure that all of the bearings are oiled and that none have been overlooked. ^Vhen running afternoon and evening all of the bearings should be oiled twice during the day, besides which the Geneva movement and governor shaft pivots should be oiled after every other show, or make sure that there is a sufficient amount of oil in the Geneva movement casing, that the Geneva movement is kept constandy lubricated. It is important that the oiling should be carefully done, and that none of the bearings should be overlooked. It is advisable to establish a practice of always oiling the bearings in the same order, as in this way you will be less liable to overlook any of them. Care should be exercised not to have any oil on the sprocket wheels and on the film pressure rollers, as oil in these places would be trans- mitted to the film and badly damage it. All surplus oil remaining on the outside of the oil holes, or in other places where it might come in contact with the film, should be carefully removed with a soft cotton cloth. The quality of oil used on a motion-picture machine is of great importance. Do not get the impression that anything sold under the name of oil is good enough. Never oil with kerosene or any oil that is highly adulterated with kerosene, as it has practically no lubricating properties. Do not use ordinary lard oil that is adapted to use on heavy machinery; it is too coarse and will gum the bearings. 172 MOTION HEAD 97 There are oils on the market, some of which are extensively adver- tised and are recommended for lubricating, polishing furniture, and as rust preventives, etc., that are not at all suitable for the lubri- cation of a motion-picture machine. Sewing-machine oil of fine grade is most desirable, and the best place to get it is at a sewing- machine agency. A cheap grade of sewing-machine oil should not be used owing to its poor quality as a lubricant. Vaseline is used in the framing device oil chamber. Remove that part of the framing device which forms the cover to t^ie oil chamber by removing the four screws in the side. Take the remain- ing part of the framing device in one hand, and with the flexible metal tube of white vaseline in the other, force the vaseline into the opening of the flange of the pin wheel, where the pin is located until that opening is well filled, then force the vaseline all around the outside of the flange of the pin wheel. Then cover the entire surface of the star with a liberal coating. This is all that will be required. Care must be taken not to put in too much vasehne, as the rapid rotation of the star and cam wheel will have a tendency to force it out through the oil cup, which would be very undesirable. After replacing the cover put eight or ten drops of fine lubricat- ing oil in the oil cup on top of the framing device, which will mix with the vaseline and soften it to the proper consistency. If care has been taken in applying the vaseline thoroughly the machine should run, even under the heaviest usage, for at least three weeks without further attention to this part, except to add occasionally a few drops of fresh oil. At the end of that period, if the vaseline has become blackened, it is time to remove it, clean the pin and star wheel, wash them off with benzine or gasoline and put in fresh vaseline as described above. Vaseline is used as a lubricant for the star and pin wheel and is without an equal for the Motiograph. It is necessary, however, to avoid the cheap qualities put up in bulk, and never, under any cir- cumstances, use carbolated vaseline. Use the white vaseline put up in flexible metal tubes, which may be had at drug stores or it may be ordered of the manufacturers of the Alotiograph. When oil only is u^ed without vaseline it is preferable to use a very heav}'^ oil of fine quality, rather than a thin oil. To keep a machine in good condition it should occasionally 173 98 THE MOTION PICTURE have the working parts cleaned with gasoline to remove dirt, gum, and old oil, the parts wiped dry with a soft cotton cloth, and fresh oil applied. The high-speed spindles of the Motiograph all run in inter- changeable phosphor-bronze bearings. These may be replaced with new ones when worn. Phosphor-bronze is one of the best anti- friction metals known, and with proper care none of the bearings should need replacing for a long time. The fire-trap rollers should be kept clean. In case the film should become ignited and the flame extend to the fire trap or valve, some of the melted celluloid is liable to stick to the rollers and when dry it becomes very hard and brittle and would do much damage to the film if allowed to remain. In a case of this kind the rollers should be carefully cleaned. The rollers should also be cleaned from time to time to keep them free from accumulations of dust, oil, etc., which will do more or less injury to the film. Alcohol or refined benzine is good for the purpose. The belt idler adjustment screw is provided with two check nuts, the purpose of which is that when the desired adjustment has been secured, one nut may be locked against the other, in order that the screw together with the nuts locked in position on the screw, may be loosened while the film is being rev/ound, as otherwise the pull would be too heavy on the film if the tension was allowed to remain the same as when the film is being taken up on the rewind. After rewinding, the adjustment screw may be instantly returned to its former position. If, for any reason, it should become necessary to remove the gear bridge of the 1908 or 1909 models, the disconnecting of the gears would throw the shutter out of time until the shutters are reset — that is, the wings of the shutter would not cut off the light at the proper moment with relation to the movement of the film, the result of which would be to show a ghost, especially on the announcements. This would not occur with the 1910 No. lA model. The shutteT might also be thrown out of time from coming in contact with some- thing inserted within the frame while the shutter is in motion. Setting the Motiograph Shutters. Setting the Intermittent Double No. 1 Cone Shutters o)i the No. lA Motiograph, Model 1910, Fig. 55. The instructions for setting the double shutters of the No. lA Motio- 174 * MOTION HEAD 99 graph for 1910 are different from the instructions for the shutters of the No. 1 Models, 1908 and 1909. The reason for the difference is that in the 1908 and 1909 Models the movement of the shutters is in the opposite direction to those of the 1910 Model. The principle of setting the shutters for the ^Motiograph is the same as for any other moving-picture machine, that is, the larger wings of the shutters should cover the light opening or aperture dur- ing the time that the intermittent sprocket and film are in motion, and the smaller wings should pass during the exposure while the film is at rest, Figs. 56 and 57. To set the shutters, remove the front plate, which carries the lens, after which remove the outer shutter wing (the one nearest you). Fig. 55. Sectional View of the Intermittent Shutter Arrangement of the Model No. lA, 1910 Motiograph loosen the screws on the inner shutter, leaving the shutter just loose enough to be turned easily by hand, and tight enough so it will not move of its own accord. Remove the gear cover, after which take hold of the balance wheel and turn the mechanism in the same direc- tion as during the operation of the machine; turn very slowly until the intermittent sprocket wheel starts to move, after which set the upper edge of the large wing of the inner shutter about Ae inch below the center of the aperture plate when looking on a line parallel through 176 100 THE MOTION PICTURE the center of the light aperture. These measurements refer to the 36-degree shutters. Now revohe the mechanism slowly in the same direction, obseiTing when the intermittent sprocket wheel stops that the lower edge of the large unng of the inner shutter is about ^ inch above the center of the aperture plate. Fig. 56. Fig. 57. Motiograph Shutter in Two Positions Tio-hten the screws firmly, after which revolve the mechanism until the inner shutter is at the original position, that is, the upper edce of the large wing should be about ^e inch below the center of the aperture plate. Replace the outer shutter on the shaft, tighten the screws partially in the same manner as was done with the inner Fig. 58. Fig 59. Motiograph Double Shutter in Two Positions of Adjustment shutter, set the lower edge of the large wing about Se inch above the center of the aperture plate, after which tighten the screws firmly, Figs. 58 and 59. After the setting of the shutters has been once done, it ^411 be very simple and easy to repeat. The width of the shutter wings that ^\^ll be furnished, unless otherwise ordered, will be that known as the 3G-degrce wings, wliich 176 MOTION HEAD 101 are best adapted to distances from 60 to 100 feet or more. The 36-degree wings are narrower than the 42-degree wings and give the greatest possible amount of exposure as compared with the non- exposure. On distances less than 60 feet, and especially where brilliantly-colored announcements are used, such as a brilliant red, there is liable to be a slight ghost of color above and below the an- nouncement. Also where there are plain whites in the picture, with heavy backgrounds around them, there is liable to be a slight ghost. These defects being so slight are, to most exliibitors, not objec- tionable in view of the advantage of a greater amount of exposure, but where they are, they may be entirely overcome by use of the 42- degree shutters, the wings of which are wider than the 32-degree. To Set the No. 2 Motiograph Shutter. Remove front plate which carries lens, loosen screws in shutter just enough so shutter can be easily turned on the shaft. Take hold of the balance wheel, revolve mechanism in same direction as during operation of the ma- chine, observe when the intermittent sprocket starts to move and set lower edge of shutter at bottom edge of aperture. Turn the bal- ance wheel until the sprocket stops, at which time the top edge of shutter should be on a hue with the top edge of the aperture. When properly set, tighten the screws in shutter. Lenses of shorter focus than about 2f inch cannot be used to advantage w^ith the regular ]\Iotiograph double or single cone shut- ters, and when lenses of shorter focus than about 2| inch are to be used, we recommend the use of the Auxiliary front intermittent shutter No. 3, which may be attached to and used with the No. lA mechanism, the first of which were placed on the market in April, 1910. With this form of shutter there is no limit and lenses of as short focus as may be desired can be used. Extreme short focus lenses should never be used where the machine could be set at a point where longer focus lenses can be used, and especially where the machine is to be located considerably above or below a line that would be parallel with the center of the screen, because at best, an extreme short focus lens requires the greatest possible care in focusing and when located at a considerable distance above or below a line that would be parallel with the center of the screen, it will not be practicable to get a sharp focus on all parts of the picture. 177 102 THE MOTION PICTURE To Attach the Auxiliary Front Intermittent Shutter No. 3. The auxiliary front intermittent shutter No. 3 is used in front of the lens. It is mounted on a front plate, which is to be used in place of the regular front plate that comes with the Motiograph Model No. lA. On the shutter shaft is a beveled pinion and for connection with this pinion is a second beveled pinion, which is furnished with the shutter and front plate. This second beveled pinion is to be attached to the shutter drive shaft on the inside of the mechanism, by first removing the larger beveled gear that is attached to the shutter drive shaft. These beveled gears are held on the shutter drive shaft by a single screw. There is a steel plate attached to the center of the gear, on which there is a tongue which engages with a groove of the same size in the shutter drive shaft. Care should be exercised that the tongue is properly engaged with the groove in the shaft before Fig. 60 Fig. 61 Before the Lens Shutter in Two Positions of Adjustment tightening the screw. When using the front shutter, the wings of the regular cone shutters, No. ] and No. 2, should be removed. To Set the JSIo. 3 Shutter. Place the shutter on the shutter shaft, as shown in Fig 55. It is held in place on the shaft by a thumb nut on the end of the hub. The shutter consists of three wings, one of which is larger than the other two. The large wing is intended to cut off the light while the film is in motion and the other two serve as interrupters for the reduction of flicker. To set the shutter in time with the intermittent film sprocket, loosen the thumb nut on the hul) of the shutter, take hold of the balance wheel and turn the mechanism very slowly in the same direction as when in operation until the intermittent sprocket begins to move. Set the top edge of the large wing so it is about | of an inch above the center of the 178 MOTION HEAD 103 lens, Figs. 60 and 61. Now turn the balance wheel until the inter- mittent sprocket stops, then see that tlie lower edge of the large wing of the shutter is about \ of an inch above the center of the lens. The shutter should be set as far back on the shaft as is practicable, that is, not to exceed about | inch from the front of the lens mount. When properly located tighten the thumb nut on the shutter hub. \Mien long focus lenses are to be used, the shutter may be reversed on the shaft, that is, the hub and thumb nut placed at the rear. This will make it possible to set the shutter well to the front, so as to pass in front of a long focus lens. \^^len using alternating current of 60 cycles, two interrupters may be objectionable, owing to the fact that at times the alternation of the current is liable to run synchronously with the interrupters in the shutter in such a way as to very largely cut down the illumina- tion. Wliere this condition exists, the only remedy is to use a shutter having but one interrupter. Index of Parts for the Mechanism of the No. 1A Motiograph Model 1910, Figs. 62 to 67 Inclusive lA Main frame of mechanism 2A Base 3A Gear cover SiA Gear cover for motor pulley and idler 4A Bridge 05A Framing device (vertical part) 06 Framing device (horizontal part) 7A Upper reel arm — casting only 8 Upper reel arm cap 9A Lower reel arm 10 Arm idler tension 11 A Framing lever 12A Main clamp thumb wheel and screw 13A Crank without handle 013 A Crank handle complete 14 Balance wheel 15 A Main gear 16A 17A 18A 19 20 21 22 23 24 25 26 028 29 30 Gear and pinion between crank shaft and balance wheel pinion Gear on lower sprocket shaft Gear between balance wheel shaft and lower sprocket shaft Governor crank complete Small belt pulley and screw Large belt pulley and screw Lens mount ring Intermittent roller bracket Roller bracket, top, with ar- bors Roller bracket, bottom Spider for fireproof magazine Bushing for intermittent sprocket arbor Magazine latch, large piece Magazine latch, small piece 17Q 104 THE MOTION PICTURE Fig. 62. Motiograph Par 3 180 MOTION HEAD 105 pinion, pinion, 31-32 Magazine hinge 33 Fire trap, casting only 33ct Fire trap, complete with rol- lers 37 Lens arm bracket 38A Shutter arbor and solid 39A Shutter arbor and main, hollow 40 A Governor drive shaft 41 A Shutter drive shaft screw 42 A Bushing for governor drive 43 A Screw for intermittent sprocket 44A Screw for gear on upper sprocket arbor 45A Bevel gear on shutter drive shaft 46A Bevel gear on shutter shaft 47A Intermediate pinions in gear case 48A Screw for clamping shutter wing 50A Crank arbor with pin 51A Upper sprocket arbor 52A Lower sprocket arbor 055 Ball arbor 056 Knuckle joint socket on Ge- neva arbor 57 Reel arm socket arbor 58 Reel arm vertical arbor 59A Reel arbor, upper 60A Reel arbor, lower 61A Balance wheel arbor and socket 62A Balance pinion and sleeve 63 Upper fire shield 64 Lower fire shield 65 Governor arbor 65G.C. Governor complete 69A Bushing for shutter drive arbor 71 Framing device guide rod 72 Framing device slide rod and head 74 Framing lever joint screw 75 Framing lever handle 76 Framing lever fulcrum screw 77 Intermittent roller bracket joint pin BOA Bushing for gear case (rear) 83 Governor crank arbor 84A Gear on governor drive shaft 085 Bevel gear on crank arbor 86 Bevel pinion on upper reel arm arbor 86^ Bevel pinion on rewind socket arbor 87 Gear on upper sprocket arbor 87^ Intermediate gears, small 89 Bevel gear on reel arm vertical arbor 90 Gear on governor arbor, and hub 91 Stereopticon slide rod 91| Stereopticon slide rod, nut, and washer 92A Screw to locate gear case 93 A Screw to retain gear case 94 Push rod for reel arm 95 Locking pin for rewind shift 96 A Film tension jaws, each 97A Heat arrester gate 99A Thumb screw for front plate 0100 Geneva driver and arbor, com- plete 0101 Intermittent sprocket arbor and star 102 Screw for eccentric bushing, framing device 103A Screw to retain shutter drive bushing 105A Cap for hole in foot of main frame 181 THE MOTION PICTURE S6 >^ .eso 38 A -^ ,80 A Fig. 63. Motiograph Parts \80A VSJA 182 MOTION HEAD 107 106 Sprocket, upper or lower 167A Connecting bar for framing 0107 Intermittent sprocket device 108 Film roils 168 Rack for fire shutters 109 Idler pulley 169 Governor strips, each 110 Roller guide on governor 170 A Shutter wing (outer) with col- shaft let and screws 111 Governor balls 171A Shutter wing (inner) with col- 112 Oil cup let and screws 114A Gear casing for shutter, com- 172- Front plate plete with gears 174 A Film tension spring 116 Roller, top of door (2 rolls and 175 Governor springs shaft) 170 Collar on reel arm vertical arbor 117A Locating plunger for crank 178 Large liushing vertical reel handle arbor 118A Spring for locating plunger 181 Bushing for balance wheel 119 Center pin in hinge of fire arbor, small magazine 182 Bushing for balance wheel 120A Side plate arbor, large 123 Collar on door latch rod 183 Small bushing for intermit- 125 Door latch rod tent sprocket shaft 126 Door roller pin 0184 Eccentric bushing for framing 127 Ball screw and door hinge device 128 Screw for upper and lower 193 A Bushing in bridge for govern- reel arm or shaft 129 Screws for gear and idler 194 Bushing in frame for governor 133 Pin in governor arbor shaft 135 Pin for motor drive 198 Bushings in reel arm (small) 0136 Pin in Geneva driver 200 Screw in governor crank 146 Pin reel arm vertical arbor 202 Locating screw for idler 148 Pin in gear on governor arbor bracket spring 154 Screw in crank 203 Screw for Nos. 23, 24, 25 155 Screw in handle of crank 204 Screws for sprockets, upper 156 Adjusting screw on take-up and lower idler 205 Screw for balance wheel 157 Check nut on take-up idler 200A Screws for shutter collet 158 Pin in vertical reel arbor gear 207 Screws for upper reel arm cap 160 A Door plate 208 Locating screw for front plate 162 A A perture plate 209 Screws to fasten magazines to 163 Brass shutter and pinion spiders 164A Heat arrester 210 Screws for spring on framing 165 Stripper plate device 183 108 THE MOTION PICTURE Fig. 04. Motiograpli Parts 184 MOTION HEAD 109 211 213 214 215 Screws for stripper plate 224A Screws for bridge 216 217 218 219 Screws for small bushing, 225 framing device 227 Screws for large bushing, framing device 228 Screws for framing device cap Screws for bushing in bridge Locating screw for idler ten- sion arm Screw for bushing in governor shaft Fig. 65. Motiograph Framing Device Parts Assembled Screws for friction on vertical 230 rod Screws for aperture plate 231 Screws for fire shields 232 Screws for studs on door 233 Screw in reel arbor bevel pinion Upper screw for gear cover Left side screw for gear cover Right side screw for gear cover Fig. 66. Parts for No. 2 Motiograph Mechanism 220 Screws for door latch 221 Screws for tension springs 222 Screws for stop on door 223 Screws for roller arbors 235 Screw for holding bushing in frame 237 Screw for attaching magazine to reel arm 185 no THE MOTION PICTURE 238 Magazine body and cover 273 241 Check nut on roller bracket 244 Screw for locating crank- handle 274 245 Set screw in socket arbor 275 246 Screw in roller bracket 248 Safety cap for crank arbor 276 249 Screw to hold roller bracket in place 277 251 Roller for fire trap, plain 284 252 Roller for fire trap, with flange 285 253 Pins for roller arbor 286 254 Tension plunger in fire trap 287 255 Screws to hold traps to maga- 288 zines 289 256 Screws for fire trap 257 Screws for jiut on reel arbor 290 258 Spring for pressure rollers in fire trap 291 258i Spring for gate latch 259 Set screw to bind bushing in reel arm 292 261 Wood handle for crank 293 262 Screws to check guide rod 263 Screws for small belt pulley 294 265 Screws for roller bracket 295 springs 296 267 Screws for framing device 297 bushing 298 268 Screws in magazine latch 299 Springs for framing device (2 pieces) Springs for roller bracket (3 pieces) Springs for front plate (2 pieces) Set screw for large bushing on balance arbor Take-up belt Spring for push rod Balance arbor screw Motor drive arbor Shutter drive arbor and pinion Gear case Screws for bushing in gear cases Arbors for intermediate gears in gear case Screw in gearon lower sprocket arbor Adjusting screw for eccentric bushing in framing device Screw for socket Geneva arbor Screw for upper fire shield Latch pin for side plate Nut for latch pin Spring for latch pin Screws for side plate Bushing for gear case (front) MOTIOGRAPH No. lA ARC LAMP MG 1 Burner slide MG 1} Machine screws MG 3 Main body MG 3 J Main body stud to hold upper castings MG 4 Lower horizontal casting MG 4i Stud MG 5 Upper horizontal casting MG 5+ Upper horizontal casting stud MG 9 Carbon clamp, complete; long (1) MGIO Carbon clamp, short MGll Upper carbon clamp bracket MG12 Upper rack bracket MG 4i Lower horizontal casting stud ]\IG16 Lower carbon clamp bracket MG 4} Roller MG17 Lower rack bracket I 186 5 ? 03 _■ I <: &q ►J o O S o MOTION HEAD 111 MG18 Upper rack MG39i MG19 Lower rack MG20 Screw for lower horizontal MG40 casting MG40i MG22 Rack plate MG40| MG22^ Screws MG41 MG23 Rack pinion and arbor Rack pinion ball, joint and pin MG46 Rack pinion ball screw Shaft to operate racks, com- MG465 plete - MG47 MG24 MG24 MG25 Swivel screw for up and down adjustment Socket Ball joint screw Pin Shaft for up and down ad- justment, complete Wood handle on up and down adjustment Screw for wood handle Plate on lower carbon clamp Fig. 67. Parts for Motiograph No. lA Arc Lamp MG26 Wood handle for shaft racks MG39 Swivel for up and down ad- MG26i Screws for wood handle, rack justment shaft MG47j Screws for plate MG30 Shaft for side adjustment, MG48 Wing nuts for carbon clamps complete (2)^X24 MG31 Wood handle, side adjustment MG49 Machine screws to hold short MG3U Screw for wood handle clamps (2) 10 X24 MG32 Swivel collar for side adjust- MG50 Washers for short carbon ment clamps MG33 Screw to hold swivel collar MG53 Machine screws to hold long MG34 Washer on side adjustment clamp to bracket (4) | X24 shaft MG54 Thumb screws to hold wire, MG38 Screw for up and down ad- (2) justment MG55 Washers for Xo. 54 (4) 187 112 THE MOTION PICTURE MG56 Machine screws to hold MG64 brackets MG.57 Machine screws to hold upper bracket on rack, (1) 10 X24 MG58 Machine screws to hold upper rack on bracket (1) 8X32 MG59 Machine screws to hold lower rack on bracket (2) 8X32 MG62 Mica insulators — flat — set MG63 Mica insulators round bush- ing Mica insulators round wash- ers Iron washers for M.G. r)G Main body No. 2 and stud (for use on Xo. 2 Motio) Shaft for Xo. 2 up and down adjustment, complete (for use on X"o. 2 Motio) MG85 Rack body (new style) MGS6 Bracket for rack body (new style) MG65 MG75 MG80 UPPER CARBON ADJUSTMENT FIXTURE MG91 Rack bracket for adjustment fixture MG92 Adjustment bracket for car- l)on clamp MG93 Support bolt MG94 Adjustment screvv MG95 Adjustment handle MG96 Clamp bolt MG97 Collar for adjustment screw MG98 Stock washer rV X/s inch MG99 Stock screw — round head, 8-32 X 1 inch • MGIOO Pin for collar for adjustment screw /aXi inch MGlOl Headless screw for adjust- ment thumb nut UPPER UNIVERSAL CARBON CLAMP MGllO Bracket (long) MGlll Clamp screw for bracket MG112 Locating screw for bracket MG113 Swivel for bracket MG114 Clamp screws for swivel MG115 Washers for clamp screws for swivel MG116 Carbon holder MGl 17 Wing nut for carbon holder LOWER UNIVERSAL CARBON CLAMP MG118 Bracket (long) MG119 Clamp screw for l^racket MG120 Locating screw for bracket MG121 Swivel for bracket MG122 Clamp screw for swivel MG123 Washers for clamp screws for swivel :MGr24 Carbon holder MG125 Wing nut for carbon holder MGl 26 Stop plate on carbon holder MGl 27 Screws for stop plate 188 MOTION HEAD 113 POWER'S NO. 5 CAMERAQRAPH The Power's No. 5 caraeragraph is a projecting machine which has been well known for several years. The right side, or crank side, Fig. 6S. Crank Sick; of Power's No. 5 Cameragraph of the motion-head mechanism of the No. 5 model is shown in Fig. 68, while the reverse, or left side, is shown in Fig. 69. In the illiis- 189 114 THE MOTION PICTURE trations, the motion head is equipped with an upper reel hanger, holdino- an open reel for the feed reel of film, instead of the iron fire- Fig 69. Left Side of Power's No 6 Cameragraph proof magazine. By the turning of two thumb screws, the upper reel hanger may be lifted off and the fireproof magazine hung in 190 r I MOTION HEAD 115 its place. This furnishes a convenience in packing, and in working about the motion head to clean it up before beginning the evening's run of the show. The intermittent mechanism is the standard three-sprocket type, upper steady feed, intermittent sprocket at the film gate, and lower steady feed below. The intermittent (in the No. 5 mechanism) is driven by the Geneva form of drive, kept in balance by a heavy fly wheel mounted directly upon the pin shaft of the intermittent mechanism. The four-slot Geneva star and one-pin cam is used, and the mechanism is timed to about j motion and f rest for each picture. The shutter of the No, 5 model is within the motion head, mounted very close to the film window. It projects near the crank handle of the motion head, and is covered by the curved shield seen near the handle in Fig. 68. The shutter is of the so-called "balanced" or multiple wing t^^pe, two wings being used, the broader one cover- ing the aperture during the shift of the film and the narrower one being introduced to reduce the flicker. The framing mechanism is a sliding carriage on the main body of the motion head; it carries the intermittent sprocket, the pin wheel, and the star wheel, and it is shifted by a short framing lever having a toggle joint with the carriage. An ingenious arrangement of gearing is pi*ovidetI by which a constant meshed gear connection is maintained between the crank shaft — which is mounted rigidly in the main body of the motion head — and the Geneva movement, which is carried movably by the framing carriage. A spur gear on the main body and a spur gear on the pin-wheel shaft of the framing carriage have an idler spur wheel between them, the idler being hung upon a pair of movable arms which keep it at all times meshed with both of its meshing gears in the train. The presser rollers by which the film is kept in engagement with the feed sprockets are all mounted in pivoted brackets, con- trolled by springs, and are provided with set screws by which the rollers may be adjusted to the sprockets to secure proper control of the film. The aperture plate is provided with hardened steel guide strips on its face for guiding the film. On the film gate, in front of the 191 116 THE MOTION PICTURE film window, and on the lamp-house side, is a heavy plate called a "coohng" plate, apparently having no function in the operation of the machine, but its purpose is to prevent the rays of the lamp from shining directly upon the film gate and heating it to a high degree which would endanger the film. The upper reel hanger is provided with a rewind handle, hence it is not necessary to detach the main drive handle or move it to a new position to rewind the film. The rewind handle does not engage Fig. 70 Cameragraph Lamp House, No. 5 Model the feed reel until pushed in upon its shaft, so it does not interfere with the turning of the feed reel during the unwinding of the film for projection. The lamp house slides u\vni a double rod track to pass from the motion head to the stereo lens, or vice versa, and this double-rod cross track in turn slides u])on a pair of rails or rods upon the pro- jection table which enables the lamp house to be placed at any desired distance from the motion head and stereo lens, thus afford- ing every facility for the projection operator to get his condensers and his lens into proper focal relation with each other. The lamp house and its double arrangement of cross tracks is shown in Fig. 70. 192 MOTION HEAD 117 The lamp is a two-knob lamp, eas}- for the beginner to control during the projection of the pictures, because he is not likely to turn the wrong knob and throw out a carefully adjusted screen illumina- tion. The lamp is shown in Fig. 71. The larger knob is the feed knob, by which the arc is struck and the carbons are fed down as they burn away during projection. The smaller knob is the tilting knob, by which the lamp frame of the lamp, including the feed rods, carbon clamps, and carbons, is tilted up or down, according as the Fig. 71. Cameragraph Lamp, No. .5 Model knob is turned, to bring the arc into proper center with the con- densers. The proper distance of the arc from the condensers and the proper transverse or side adjustment of the lamp is made inside the lamp house, through the door. The height is made by the slid- ing block and set screw which clamps it to the vertical rod of Fig. 71, upon which the lamp frame is mounted. The distance from the condensers forward or back in the lamp house is made by mo\ing the base of the vertical rod, in the house, but in some of these lamps there is a third knob projecting at the very bottom of the lamp house at the back, and the lamp may be slid toward or from the condensers by turning this extra knob, which is so low that it is not likely to be 193 118 THE MOTION PICTURE touched bv accident during projection. The design of the Power's lamp and lamp house is such as to avoid accidental moving of parts which should be left alone during projection. The top of the Power's lamp house is liinged, and may be swung upward to afford convenience in setting the carbons, the oper- ator passing one hand through the top of the lamp house and the other through the door. The lamp house also has the douser shut- ter between the condenser and the lantern slide, instead of at the end of the condenser hood, thereby protecting the slide when not being projected. The fireproof magazines for feed and take- up reels are provided with a special type of roller fire trap, shown in Fig. 72. It \nll be noticed that one of the rollers of the fire trap has its shaft projecting at both ends. In feeding the film end through the trap, the ends of this roller are caught with two fingers and the roller is slid back in its slots to per- mit the end of the film to pass. The Power's machines are equipped with two styles of fire shutters. Style A is shown in Fig. 73. It is operated by an inward movement of the driving crank upon the shaft. The crank is set upon the shaft with a cam slot and a pin and spring, so that when the power is appHed to turn it, it automatically moves inwardly to open the shutter. Style B is shown in Fig. 74. This shutter requires that the mi^'hanism have a certain speed of revolution before the shutter will operate to open the film window to the light of the arc lamp, and it is operated by a centrifugal wheel geared to the film dri\ang mechanism of the motion head. Upper and lower film shields are shown in Fig. 74. The lower shield is hinged at the bottom, to per- mit the operator to get at the mechanism for threading up the film. Figs. 75 and 76 give illustrations of such parts of the Power's No. 5 Cameragraph as are likely to be needed for repairs, and iden- tify them by number. In ordering a repair part, both name and number should be ijiven. Fig. 72. Cameragraph Film Outlet and Fire Trap 194 MOTION HEAD 119 Fig. 73. Cameragraph Safety Shutters, Style A I'ig. 74. Cameragraph Safety Shutters, Style B 195 120 THE MOTION PICTURE 1 1 r n Ik 'i\\ ii \ 5/ rs 74 rs Fig. 75. Parts of No. 5 Camcragraph 196 ?l MOTION HEAD 121 INDEX OF PARTS 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 Reel hanger frame 38 Machine top frame 39 Machine body frame 40 Machine framing carriage 41 Machine base casting 42 Take-up feed frame 43 Machine crank 44 Fly wheel 45 Stereo bracket with thumb 46 screw 47 Stereo bracket holder 48 Crank shaft bearing 49 Framing device lever socket 50 Framing device clamp 51 Framing device link for lever 52 Top feed smng bracket 53 Cooling plate 54 Toggle joint, large arm 55 Toggle joint, small arm 56 Stereo flange collar casting 57 Take-up feed roller bracket 58 Intermittent roller bracket 59 Steel thumt) screw, nickeled 60 plain 61 Reel hanger shaft 62 Reel hanger gear Reel hanger crank 63 Reel hanger crank handle 64 Heavy feed sprocket 65 Feed sprocket shaft 66 Feed sprocket gear 67 Wing nut 68 Set collar 69 Reel hanger spindle Reel hanger spindle gear 70 Shutter shield 71 Toggle joint set collar 72 Aperture plate 73 Toggle joint spindle 74 Toggle joint gears Intermittent bracket spindle Intermittent bracket spring Intermittent bracket roller Intermittent roller set collar Upper feed gear and spindle Framing lever Crank shaft gear Steel peeler Apron Take-up feed driving pulley Geneva or star wheel Eccentric bushing Intermittent sprocket, light Intermittent shaft or spindle Eccentric bushing (end view) Plain bushing Shutter, revolving Shutter gear, each Shutter set collar Shutter spindle Top feed bracket spring Front plate Base board for mechanism Take-up feed roller bracket spring Gears for take-up feel Hea^'y sprocket for take-up feed Take-up feed spindle Film tension springs Latch for door Plate door or gate Guide rollers, spindle bushings and springs Pin wheel or Geneva driver Main spindle Steel pinion Machine frame support Maciiine frame support 197 122 THE MOTION PICTURE Fig. 76. Parts of No. 5 Cameragraph 108 MOTION HEAD 123 75 Stereo lens bracket rod 125 Coil for 120 volt circular rheo- 100 Arc lamp base, complete stat 101 Arc lamp base casting, with post 126 Coil for 25 amp. rheostat 102 Arc lamp base adjusting screws 127 Coil for 240 volt circular rheo- and handle stat 103 Dowser, complete 128 Rheostat crank, complete 104 Dowser shield 129 Rheostat crank casting 105 Dowser handle 130 Rheostat crank handle 106 Dowser handle casting 131 Rheostat crank contact spring, 107 Dowser handle knob small 108 Funnel support 132 Rheostat crank contact spring. 109 Condenser mount bracket cast- large ing, lower 133 Arc lamp rack handle 110 Condenser mount bracket cast- 134 Arc lamp carbon holder, com- ing, upper plete 111 Rheostat binding post casting 135 Arc lamp carbon holder jaw 112 Lamp house sliding, sleeve 136 Arc lamp carbon holder lip 113 Lamp house sliding rod, longi- 137 Arc lamp carbon holder knuckle tudinal lower 114 Lamp house sliding rod, cross- 137 A Large plain thumb screw for wise knuckle ' 115 Lamp house sliding rod, exten- 138 Arc lamp carbon holder knuckle sion upper 116 Lamp house sliding rod, holder 138A Small plain thumb screw for bracket lower knuckle 117 Lamp house stop with thumb 139 Arc lamp carbon holder knuckle screw bracket 118 Binding post for circular rheo- 140 Xo longer used stat 141 Arc lamp supporting Iiracket 119 Binding post for 25 amp. rheo- 142 Arc lamp supporting bracket stat thumb screw 120 Coil terminal for 25 amp. rheo- 143 Arc lamp adjustment rack guide stat casting 121 Coil terminal for 25 amp. rheo- 144 Arc lamp adjustment rack stat (end) handle, small 122 Coil terminal for circular rheo- 145 Arc lamp adjustment rack stat (intermediate) 146 Arc lamp adjustment rack cast- 123 Jumper spring for circular rheo- ing pin stat terminal 147 Arc lamp name plate 124 Coil terminal for circular rheo- 148 Rheostat (25 amp.) adjustment stat (double), complete base, complete 199 124 THE MOTION PICTURE 149 Rheostat (25 amp.) crank, com- plete 150 Center post of 25 amp. adj. rheostat 151 Stop spindle on circular rheostat 152 Center post on circular rheostat 153 Upper magazine spindle 154 Lower film shield 155 Lower film shield hinge spring 156 Upper film shie! 1 157 Machine crank for style "A" mechani.5m 158 Crank spring with l)utton for style "A" mechanism 159 "V" spring for style "A" mechanism 1(30 Crank shaft for style "A" shut- ter mechanism Ibl Crank .shaft and pinion for style "B" shutter mechanism 162 Lever for style "A" shutter 163 Lever for style "B" .shutter 164 Lever support for style "B" shutter 165 Friction case cover, style "B" shutter I GO Friction case cover, style "B" shutter 167 Friction shoe, style "B" shutter 168 Friction weights, style "B" shut- ter, each 169 Crank shaft l^earing for style "A" shutter 170 C^ooling plate and flap complete for automatic shutters 171 Rock shaft for style "B" shutter 172 Rock shaft for style "A" shutter 173 Left bearing for shaft, style "B" shutter 174 Right Ijearing for .shaft, style "3" shutter 175 Pivot for lever, style "A" .shut- ter 1 76 Ruby glass frame for lamp house door 177 Wooden knol) for lamp house door 1 78 Catch holder for lamp house door 1 79 Catch for lamp house door 180 Valve for upper magazine 181 Valve for lower magazine 182 Support casting for lower maga- zine 183 Cross casting for lower magazine 184 Reel cotter 185 Cross casting for upper maga- zine 186 Lower take-up attachment 187 Front take-up attachment 188 Take-up spindle 189 Take-up spindle tension spring 190 Split pulley for take-up attach- ment 191 Guide roller casting for lower take-up attachment 192 Guide roller for lower take-up attachment POWER'S NO. 6 CAMERAQRAPH The intermittent movement of the No. G model Is a radieal departure from that of the No. 5 model, and indeed from all pre- viou.s nittdels of intennittents. It ha.s no pin wheel, no star wheel, 200 MOTION HEAD 125 no Geneva. It is not a beater, dog, nor claw. Neither is it a friction grip. Two parts are used, similar in relation to the cam wheel and star of the Geneva, but rather reversing the order, since the pin wheel is the intermittent. The driving element is a revolving cam, substantially diamond shaped, upon the face of a heavy steel disk carrying also a steadying or locking band, as is carried by the pin wheel of a Gene^•a. The driven element is a cross upon the end of the in- termittent shaft. In each of the arms of the cross is a pin. The cam band and diamond drive block upon the face of the driving disk are shown in Fig. 77, as are also the cross and pins, separated from their Fig. Intermittent Movement Meelianism, Power's No. 6 Model driving and locking elements. The position of the pin cross is shown in dotted lines in the locking band. In manufacture, the cross and pins are cut from a single block of steel. The parts of the intermittent movement are enclosed in an oil-tight casing, with an oil feed cup, and by keeping the casing properly filled with oil a practically noiseless movement of the intermittent drive is assured, Fig. 78. The shutter is of the three-wing type, and is mounted upon a spindle which projects forward from the front plate of the motion head, so that the shutter intersects the rays of light in front of the projection lens. The shutter is adjustable longitudinally of the spindle, so that it can be set close to the front of the lens whether a long or short focus of lens is used. The hub of the shutter con- sists of an inner and outer sleeve; the inner sleeve is directly and permanently attached to the spindle, and the outer sleeve is adjustable 201 126 THE MOTION PICTURE upon the inner sleeve to permit quick and accurate setting of the shutter with relation to the intermittent movement. The mount- ino"s of the shutter spindle are such that when the shutter is detached for packing the mechanism, the spindle is swung down into close con- tact with the front of the motion head, where it will be protected from injurv in shipment. Owing to the rapid movement of the film produced by the new intermittent mechanism (one-sixth movement and five-sixths rest for each picture interval), the shutter wings may be cut narrower than in most shutters of the three-wing type, thereby giving the screen all possible advantage of the lamp. If the oper- ator does not try to burn his lamp too brightly he should be able to Fig. 7S. Complete No. G Cameragraph Intermittent Mechanism } get his flicker well down toward elimination with the No, 6 model cameragraph, but if he tries to crowd on all the light he can from his lamp, the brighter illumination of the screen by the narrower .shutter blade will bring back some of the flicker which the rapid film shift endeavors to reduce. The shutter gears are angle gears (not bevel gears), and have faces f of an inch in width, thus insuring long service without perceptible wear. 202 s ^ hj ■- P< _ o ■ O ; o : OS i;- fc ■- w = ^ ? W -I o b < u M : O rt O^ 2 -^ i «JJ - = H -£- 21- = H = J D - 5 O >-- w -•"- W r J IZI — J « "" o =•- u. - — ^ 2 o - OS g MOTION HEAD 127 The picture is framed by a slight vertical movement of a car- riage bearing the intermittent sprocket, and the framing lever is mounted on the base of the mechanism or machine head, where it Fig. 79. Power's No. 6 Cameragraph can be readily reached with the left hand without interfering with the operation of the machine. The movement of the framing car- riage does not alter the relation of the shutter to the picture gauge or projection aperture. The gearing connection to the framing car- 203 128 THE MOTION PICTURE riage has all the gears arranged in a straight hne, eHminating a toggle joint and toggle joint gears. The film feed comprises three sprockets in accordance with the usual American practice. The top feed sprocket and the bot- tom or take-up feed sprocket run constantly, and the middle or in- termittent sprocket makes a complete turn in four successive move- ments with alternate periods of rest, which are four times as long as the periods of movement. All the sprockets are cut from specially selected steel to insure long wear and accuracy of size and form. Fig. SO. Camerag aph No. 6 Lamp The film is held in position upon the top feed sprocket by means of two rollers, one a flanged guide roller turning on a fixed spindle, and the other a holding roller mounted on a spring pressed bracket. The latter roller rests directly over the top feed sprocket when in use and keeps the film in perfect engagement with the sprocket teeth. The film is held in position on the intermittent sprocket by means of a roller mounted on a pivoted bracket, which is so shaped that it serves also as a guide for the film. When the idler roller for the intermittent sprocket is in service it lies practically under the inter- 204 MOTION HEAD 129 mittent spindle and insures engagement of die film with at least four teeth on each hub of the intermittent sprocket. A pair of idler rollers are provided to keep the film in position upon the lower or take-up feed sprocket, these idlers being mounted in a frame w4iich is arranged to rock on a spindle carried by a spring pressed, pivoted bracket. The lower, or take-up, feed sprocket controls the rate at which the film is taken up in the lower magazine, and it is of the utmost importance that "riding" of the film on this sprocket be prevented. This is completely accomplished by means of the arrangement of idler rollers. Fig. 81. Power's Rheostat To prevent wear of the film in traveling o\er the sprockets, all the idler rollers which hold it in position thereon are so supported that no pressure of the film against the sprockets is produced by the idler rollers, but the possibility of disengagement of the film with the sprockets is completely obviated. The film guides and friction devices are arranged to make the friction of the film through the motion head as light as possible. At the top of the gate a pair of hght flanged rollers are pro\ided through which the film tra\els to the aperture plate. The tension on the film necessary to insure steady pictures is produced between guide rails or wear strips of hard steel on the aperture plate and a 205 130 THE MOTION PICTURE pair of tension springs provided with half-round hardened steel tension contact shoes. To prevent wear on the film in passing from the intermittent sprocket a steel apron with polished surface is pro- vided, over which the film travels with but litde friction. The usual safety devices of upper and lower film magazines, fire shields, fire traps in the magazines, film shields, and safety shutter are used in the No. 6 model and are similar to those described in the No. 5 Model Cameragraph. The lamp house of the No. 6 model has its four adjustments out- side of the house, the lamp being mounted upon an iron frame inside the house, and being accessible from all sides by reason of doors in both sides of the house and a swinging top upon the house as well. The No. 6 cameragraph mechan- ism is shown in Fig. 79, and the No. 6 cameragraph lamp in Fig. 80. The Power's rheostat, which accom- panies the Power's projecting ma- chines, is shown in Fig. 81. The Icnob on the front may be moved to the right or to the left to change the amount of current taken by the arc lamp from the power mains. For alternating current only, the rheostat of Fig. 81 may be replaced by the Power's Inductor Fig. 82, but not for direct current. Fig. 82. Power's Inductor PATHE PROFESSIONAL MODEL PROJECTOR The Pathe projecting machine introduced into America is the tvpe known as their "Professional ]\Iodel." The Pathe machine differs in one essential respect from all other projecting machines which have reached any wide sale in America, in that it is made entirely in Europe, being made in the Pathe workshops in Paris. The shops there employ over five hundred people in the manufacture of projecting machines, and the output is four hundred complete 206 1 MOTION HEAD 131 machines per week, the result of gradual growth from a beginning which dates back to the beginning of the industry. This data is here given to inform the reader that the Pathe Professional Model projector, which is a new machine to the American public and to the American branch of the motion-picture industry, is not an experi- ment. Not the motion head alone, but every part of the entire machine is made in Paris. It is urged as an advantage that Europeans are very accurate and careful in building machinery; that owing to the very low price of labor more time can be given to the work of each machine; and that as a consequence the Pathe Professional INIodel projector is carefully and perfectly constructed. Against this, it is urged that the foreign manufacture is an objection to the Pathe machine, upon the assumption that in the case of a breakdown it would be hard to obtain repairs. Wa^^ng aside as biased the usual manufacturer's claim that the machine is incapable of breakdown, full weight still must be given to the fact that Pathe Freres carry a complete stock at their American factory at Bound Brook, New Jersey, and at their offices and supply stations in New York, Chicago, and San Francisco. All this is not for the purpose of boosting the Pathe machine, but for the purpose of making the reader familiar wdth some facts of interest in connection with the motion-picture industry, and to brush away that prejudice which the patriotic American attaches to every- thing of foreign manufacture. The Pathe machine is one of the foremost in use in America today. In the early days, there was no sale for a machine of so high a price, but with the steady growth of the industry Pathe Freres began to push their macliine and it found a wide market. The complete Pathe outfit is shown in Fig. S3, the view being taken from the operator's side of the table. The intermittent movement is a one-pin Geneva mechanism. The star wheel and pin cam are placed in a lubricating box to reduce friction and wear and also to reduce noise. The construction of the intermittent mechanism is calculated to give a ratio of six to one, that is, one-sixth motion and five-sixths rest for the total picture interval. This is with a view to giving a sharp picture free from flicker, ^^^len the light is not crowded to its limit, the Pathe pro- 207 132 THE MOTION PICTURE ]'ector is capable of verv delightful projection, and the operator should set about getting it. With the stiff table legs and the floor "socles" as Pathe Freres prefer to call them, the machine can be made rigid. In connection wath this, the manufacturers recommend an arc light using only twenty-five amperes. Fig. 83. Pathe Professional Outfit The shutter is placed in front of the lens. It is a three-wing multiple-blade disk shutter, sixty degrees in each wing, the Ameri- can standard shutter for all modern machines. f 808 MOTION HEAD 133 The film feed system is the American standard, triple sprocket system. The top sprocket runs continuously, feeding the film from the top magazine; the middle sprocket is intermittent, for stopping the film for exposure upon the picture screen; the lower sprocket runs steadily and feeds the film into the take-up reel in the lower magazine. The film does not touch the mechanism in any way in the center or picture strip of the film, but only in the edges where Fig. 84. Pathe Mechanism with Magazines (rear view) Open the perforations are placed, reducing as much as possible the pull or friction upon the film and the probability of scratching or damaging it. The framing device is worked by a small lever which raises or lowers the picture, and which can if desired be locked in position by a thumb screw. 209 134 THE MOTION PICTURE The automatic fire shutter holds the film window of the motion head normally closed; it is operated to lift out of the beam of light only after the motion head has begun to turn, and as soon as the speed is reduced for the purpose of stopping, the shutter again drops into position in the beam of light and protects the film in the window. The flame shields protect the film from exposure to the light and heat of the lamp and lamp house from the time it leaves the upper magazine until it is wound into the lower magazine. Fig. 85. ^Pathe Arc Lamps The flame shields are hinged at the left, as are also the safety .shutter and the film gate, so that all of the parts in front of the film as the operator views it, looking at the back of the motion head, may be swung out of the way for inspection, for cleaning up the path of the film, and for threading up the film through the motion head. Fig. 210 MOTION HEAD 135 84 shows the motion head thus opened, showing also the magazines open and the position which the film assumes in its passage through the motion head. The fireproof magazines (upper and lower) are round, with hinged doors, and roller film outlet and inlet. The film passes through between two rollers which are fitted together tightly enough to prevent flame from getting through into the magazine, yet are so constructed as not to scratch or injure the film as it passes between them. The reels in the magazines arc of steel, and are of the standard 10-inch size for 1,000 feet of film. The lamp house is of large size. It has doors on l)oth sides and a slide in the rear, in addition to which the top lifts off, enabling the operator to get at the lamp from all sides, and from the top. The lamp house is attached to the table by a system of adjustable sliding rods which permit a forward and backward movement, as well as a side movement to the position for the stereo lens when slides are to be projected. The condenser glasses are placed in a cell which is so designed as to be taken out of its sup- port easily when the lamp house is hot. The con- denser glasses are of the standard American size, 4h inches in diameter, and any condensers of ^'^^^g this size used in any other projecting machines may be used in the Pathe Professional — it is not necessary to use an imported glass. The slide carrier is of metal. The arc lamp is made of heavy steel and bronze; the lamp itself, removed from the case, is illustrated in Fig. 85. By means of the top fiber knob, the operator is enabled to feed the carbons; by means of the next knob, the small one, the operator is enabled to shift his light from left to right or from right to left; by means of the large knob third from the top, the operator is enabled to raise or lower the light; and by means of the bottom knob he is enabled to move it forward or backward and still keep it under perfect control all of the time. The carbon holders are held in place by an automatic device which does away with the necessity of tightening them with Pathe Anti- Shake Socle 211 136 THE MOTION PICTURE a screw. This automatic device also prevents the carbons from falling because of the expansion of the metal parts holding the car- bon when the lamp heats up. The angle or slope of the carbons is not adjustable. The table is a wood top with adjustable legs. Each leg is two telescopic steel tubes, held together by a thumb screw. This is showTi clearly in Fig. 83, By the adjustable legs, the table may be leveled, or may be tilted at any desired angle to get the best pic- ture upon the screen possible from any enforced location of the pro- jector. The legs may be attached rigidly to the floor, and the table shake may be eliminated by the use of a set of Pathe "socles," illustrated in Fig. 86. Rewinding of the film reel is not done with the motion head but with a separate simple rewinder, illus- trated in Fig. 87. In Fig. 88, the repair parts most likely to be needed are illustrated and numbered, and a list of parts by name and number also is given. To thread up the Pathe Profes- sional, first open up both gates and both magazine doors, opening up the back of the motion head as is shown in Fig. 84. See that the framing lever, the small brass handle on the right side of the machine, is about in the center of its motion, that is, the lever should be approximately over the "h" of the word "Pathe" on the quadrant in which the framing lever turns. Place the film reel in the upper magazine so that the film un- winds from the top. Xext, pass the end of the film between the two magazine rollers in the film outlet which is found on the lower part of the magazine. Close the upper magazine door. Draw out about a foot of film and mesh it over the upper socket. Now place the film in the film track, first, however, making a loop interiorly in the film l)etween the upper sprocket and the film track. ]\Iesh the film over the intermittent sprocket, holding the loop in place with the Fig. 87. Pathe Film Rewinder 212 MOTION HEAD 137 right hand, and close the upper gate. Turn the shutter with the hand until the film moves down, then mesh the film over the lower sprocket, allowing for a loop as described above. The lower loop should be made just long enough to avoid touching the lower chain gear shaft. A turn of the operating handle now will draw film enough through the machine to enable the operator to pass it between the rollers at the film inlet of the lower magazine and from there to the reel hub, where it is fastened in the usual manner. Turn the reel by hand to tighten up any slack film and close the lower magazine door and the lower film gate and flame shield. Be sure that the groove in the lower reel fits snugly to the pin in the lower magazine spindle. Both the top and lower reels are designed to turn counterclockwise and on no account should the spring belt of the magazine be crossed to reverse the motion of the lower reel. The tightness of winding of the lower reel can be regulated by tightening or loosening the two milled nuts on the lower magazine spindle. The manufacturers offer the following special suggestions for the care of the Pathe Professional: The fact that a machine is strongly built is no reason why it should be abused. All machinery requires lubrication, and a motion-picture machine is no exception to the rule. There are two oil cups on the shutter shaft. Two on the upper sprocket shaft and two on the lower. Three on the fly-wheel shaft and two on the intermittent sprocket shaft. One on the upper chain gear and one on the toothed gear on the right-hand side of the machine. There is also another spur-gear shaft on the right-hand side with two oil cups. The star wheel runs in oil and the lubrication case should be filled daily. The star wheel is the most important part of a motion-picture machine, as upon it the steadiness of the picture depends. The star wheel in the Pathe Professional machine is accurately adjusted at the factory and should not be meddled with. Only the best quality of machine oil should be used for lubricating the working parts. The film tracks and sprockets should be kept clean by being brushed occasionally with a clean tooth brush. The film tracks may be rubbed occasion- ally with a very small quantity of vaseline. The window frame is removable for cleaning purposes. It should not be cleaned with a knife or other sharp instrument, l)ut should be rubl^ed with a clean stick of wood. A very small quantity of gasoline sometimes is useful in cleaning the film sprockets and tracks. 213 138 THE MOTION PICTURE SfO 1 T 5ie 5/3 S19 S/4 s/s 5/6 5S0 @ 517 SSI Fig. 88. Pathe Professional Model Parts 214 MOTION HEAD 139 INDEX OF PARTS 501 Arc lamp 537 Shaft and gear for framing 502 Asbestos-covered wire with ter- 538 Shutter minal 539 Socket screw 503 Oak board 540 Spring belt 504 Lamp house, sliding base and 541 Spring for tension holder cone 542 Spring for top of door 505 Legs and flanges, complete set 543 Spring for window frame 506 Mechanism head without reels, 544 Upper sprocket with shaft magazines or lenses 545 Lower sprocket with shaft 507 Rheostat 546 Steel sprocket tension holder 508 Slide carrier 547 Steel star wheel 509 Double pole switch and cover 548 Upper steel roller 510 Automatic shutter shield 549 Stereopticon attachment 511 Bolt 550 Steel tension roller for take-up 512 Chain 551 Steel window frame 513 Upper chain cogwheel and gear 552 Binding post 514 Lower chain cogwheel 553 Carbon holder 515 Steel cog gear, 28 teeth 554 Shaft with fiber knob and gear 516 Steel cog gear, 35 teeth 555 Cone 517 Steel cog gear for take-up 556 Hood 518 Complete door with shutter 557 Fiber knob for door 519 Steel film track 558 Red glass for door 520 Upper flame shield 559 Sliding base 521 Lower flame shield 560 Sliding rod, 15 inches 522 Fly wheel 561 SHding rod, with screw end, 16 523 Framing cog gear inches 524 Bronze gear, 112 teeth 562 Condenser lens, bi-convex, 4^ 525 Gear guard inch diameter 526 Gear for shutter shaft 563 Condenser lens, plano-convex, 527 Handle 4^ inch diameter 528 Handle for framing device 564 Condenser lens, meniscus, 4h 529 Intermittent steel sprocket inch diameter 530 Upper magazine 565 Condenser mount without lens 531 Lower magazine 566 Motion picture jacket 532 Milled screw 567 Motion picture lens, any focal 533 Steel pin wheel length 534 Rack 568 Stereopticon lens without mount 535 Steel reel, 10-inch any focal length 536 Roller for magazines 569 Stereopticon mount without lens 215 140 THE MOTION PICTURE THE STANDARD PROJECTOR The unique feature of the "Standard," or ".\inerican," pro- jector is in the fihn protection. Other machines provide fireproof magazines and numerous devices for protecting the fihn from the heat of the lamp, while passing from the upper to the lower magazine, and still other shields for preventing the film from coming in contact with the lamp house when running out of the projecting head under the feed of the upper sprocket. Fig. 89. No. 2 "Standard" .\utomatic Moving-Picture Machine with Motor The "Standard" attacks this problem in a different way. A complete enclosed housing for the film is created, including the upper reel, the motion head, and the lower reel. The entire length of the film strip is protected and is completely enclosed, with the exception of the single image in the film window. The motion head is box-like in construction. The upper feed magazine is placed over the motion head and close upon it, leaving no space between in which the film 216 MOTION HEAD 141 can be exposed in passing from the feed magazine box to the motion- head box. The lower take-up magazine is placed just below the projection lens artd against the front of the motion-head box, leav- ing again no space between where the film is exposed in passing from the motion head to the take-up magazine. Because of the close fitting of the magazines to the box body of the projection head, no film-friction film outlets are used upon the magazines, either upper or lower, a flame trap being built into the box-like motion-head frame. The close construction of the three parts, upper magazine, motion head, and lower magazine, and the full protection of the strip of film, is shown clearly in Fig. 89, giving a general view of the "Stand- ard" projection equipment. Xot only are the motion head and magazines shown, but also the "Standard" table, built wholly of metal rods and tubes, the lamp house, and the motor. The show- ing of the motor in the picture recalls the fact that at one time the "Standard" was the only projection machine which was permitted to run by motor in New York, all others being compelled to turn by hand. The feature of distinction upon which this discrimination was based was that the film could not be fed by the motor and up- per sprocket to make contact with the lamp house or to fall into the beam of light outside of the motion head, because of the enclosed box construction of the entire film-handling mechanism and maga- zines. The "Standard" does not use the opaque shutter, but uses a semi-opaque or translucent shutter which gives a soft haze to the picture screen during the short interval of shift of the film. By changing the interval of darkness into an interval of haze, the flicker is reduced; and the claim is made also that an equal screen illumina- tion is produced with a smaller current consumption in the lamp. This, however, lies with the operator; the rule of less light and smoother 'picture or more light and more flicker is a fundamental principle in the optics of the motion-picture system when projection by persistence of vision is practiced, and it applies to the "Standard" machine along with the others. There is room for the exercise of the oper- ator's skill with all of them in the matter of flicker. The operator must discriminate between "flicker," which is the variation of the intensity of the light by which the screen seems to 217 142 THE MOTION PICTURE wink at the spectator, and "jiggle," which is the dancing about of the fixed objects of the projected picture, due eitlier to faulty in- termittent mechanism or film gate adjustment, or to an unsteady table which yields to the force applied to the crank handle. The single image of the film which is in the film window is Fig. 90. "Standard" Motion Head guarded from the heat of the lamp by a hinged shutter which falls over the window when the driving mechanism of the machine is not in motion. When the motion head is l^eing driven at projecting speed, a speed governor acts to engage and life the safety shutter from the film window^ and to hold it up as long as the speed of the motion head continues, dropping it before the window as soon as the motion stops. 218 MOTION HEAD 143 The intermittent movement of the fihii is obtained by the usual arrangement of Geneva mechanism. The Geneva pin wheel is so built that when the pin becomes worn a new one may be installed to replace the worn one. The lamp house is adjustable toward or from the motion head by sliding its cross track directly upon the two metal tubular rails which form the top bars of the operating table or frame. The cross track is a pair of parallel bars to permit the lamp house to be slid over for the stereo lens of the motion head as reciuired. The construction of the motion head and the course of the film through it is shown in greater detail in Fig, 90, where the side of the motion-head box and the film gate door and back plate or "back door" of the motion head are removed to reveal the mechanism. The principal parts of the "Standard" machine which are likely to be required for repairs are shown in Fig. 91 with their identifi- cation numbers; in addition, a list of the parts by name is given with their numbers. The lamp of the "Standard" machine removed from the lanip house in order to reveal all of its parts, is shown in Fig. 92, The knob D feeds the carbons. The knob B for tilting the lamp and the knob C for raising and lowering it are together, the knob C l)eing upon a rod and the knob B being upon a tube which is sleeved over the rod. This distinction of a double knob as compared with a single knob will help the operator to avoid the eiTor of turning the wrong knob and throwing his screen lighting out of adjustment when, with his eyes on the screen and his right hand turning the crank, he reaches with his left hand to feed the carbons. If, under such circumstances his hand touches the doul)le knob, he will not turn it by mistake. The knob E moves the lamp toward or from the condensers. The adjustment of the angle of the carbons with respect to each other is attained only through the door of the lamp house, by turn- ing the knob G for the lower carbon, or H for the upper carbon. By these knobs, the carbon holders may be set for direct-current or alternating-current positions, the difference in alignment between the centers of the upper and the lower carbons of the direct-current setting also being controlled by the knobs G and H. Knobs A and F are lock knobs for the carbon pencils in the holders. 219 144 THE MOTION PICTURE INDEX OF PARTS 1 Star wheel and spindle (one 7 Collar 1 piece) 8 Gear i On fly wheel 2 Bushing on intermittent spindle 9 Bronze bearing | spindle (short) 10 Collar Fig. 91. Repair Parts for "Standard" Projector 3 Intermittent sprocket 4 Bushing on intermittent spindle 5 Fly wheel spindle Fly wheel 1 1 Pin wheel 12 Engaging pin for pin wheel Hi Screw to hold pin in pin wheel (hardened) i 220 MOTION HEAD 145 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 Bronze bearing for fly wheel spindle Gear connecting with shutter gear Revolving shutter and spindle Revolving shutter gear Driving shaft spindle Chain sprocket Collar Spiral gear Clutch collar On driving shaft J Handle for driving (complete) Transmission spindle Gear 42 teeth 12 15 On transmis- sion spindle Stereopticon bracket Stereopticon bar, short Stereoption bar, long Stereopticon ring casting Mechanism fastening casting Screw for mechanism fastening casting Motor fastening casting Governor spindle Sliding gear on governor Governor head Governor wings (each) Governor arms (each) Governor pin Governor collar Gear on governor spindle (8 teeth) Fire shutter (complete) Door for machine (complete) Aperture tension cradle Filni tension guide (intermittent sprocket) Door lock (complete) Film slide and cradle (complete) Springs for aperture tension cradle (each) 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 07 68 69 70 71 73 74 75 76 77 78 79 80 81 82 83 84 Aperture plate Guiding spool for film track (com- plete) Film shutc Upper film sprocket spindle Upper film sprocket Gear I On upper film sprocket Collar J spindle Upper idler roller lever (complete) Lower film sprocket spindle Lower film sprocket Gear 1 On lower film sprocket Collar j spindle Framing device spindle Framing device eccentric Framing device handle Framing device sliding ])ox Screw adjustment for sliding box Carbon holder for A. C. (each) Carbon holder for D. C. (each) Reel spindle (upper magazine) Collar on reel spindle (upper magazine) Reel spindle with collar and lock nut (lower) Take-up bracket with tightening nut Friction plate on lower reel spindle Friction washer Large chain sprocket on take-up Spring on takq-up Chain on take-up Spindle for eccentric on take-up Eccentric bushing on take-up Set screw for eccentric on take-up Small chain sprocket on take-up Chain (take-up to mechanism) Carbon holder tightening screw Switch and switch box with nickel base 221 146 THE^MOTION PICTURE To thread the fihn through the motion head, slide the full feed reel over the spindle in the upper magazine. Open the back door of the motion-head box. Pass the end of the film between the two flame-trap rollers on the top plate of the motion-head box near the upper sprocket; then under the upper sprocket; let the pair of clamp WIRE CONNECTION Fig. 92. Electric-Arc Lamp for "Standard" Projector rollers rest upon the film, holding it against the upper sprocket. Turn the framing lever "up" as far as it will go, to make the upper feed loop as large as possible; then turn the fly wheel by hand until the intermittent sprocket just starts, then make an upper feed loop so that it will come ^ inch under the top plate of the motion-head box; pa.ss the film down the guides and over the teeth of the inter- mittent; make a small loop to lower sprocket and close the door. The film passes through the lower chute to take-up magazine and is attached to the hub there in the usual manner. Take up the slack by turning the take-up reel by hand, and give a half turn of the driv- ing crank to see that the film is being taken up properly before ' 222 MOTION HEAD 147 closing the door of the lower magazine. The precaution in forming the upper loop is necessary for the reasons that (1) if the upper loop is formed with the frame lever "down" by which the size of the upper loop may be increased when the frame lever is throw^n "up," then the upper loop when thus increased may let the film rub against the inside of the top of the motion-head box; and (2) if the upper loop is formed as large as possible when the intermittent has just finished its pull, the upper steady feed will feed a full picture, or f inch of film, into the upper loop before the intermittent pulls again, thereby in- creasing the size of the upper feed loop and perhaps permitting the film to rub against the inside surface of the motion-head box. The take-up device is adjusted by a lock nut attached to the spindle of the lower magazine box. To adjust the tension, loosen the small screw in the lock nut. A turn then to the right will irive more tension, and a turn to the left will give less tension. Wlien the tension is readjusted to suit, tighten the small set screw in the lock nut again to hold the adjustment. ^Mien the star wheel becomes worn or loosened, it can be ad- justed to the pin wheel by loosening the four screw^s which hold the bronze bearings in place. To tighten the star wheel to the pin wheel, give both bronze bearings a slight but equal turn upward and again fasten the four set screws which hold the bearings fixed as adjusted. The mechanism should be oiled thoroughly before beginning each afternoon or evening run. Do not forget to oil the leather washer between the flange and the large chain sprocket. Oil the spindle from an oil hole inside the box. THE REWINDING "STANDARD" PROJECTOR This projector is shown in Fig. 93. The take-up reel is in the square box below and in front of the motion-head box, while the feed reel, instead of being mounted edgewise above the motion- head box, is mounted flat. The operation of this machine, which is classed as an "auto- matic rewinding projector," is not that it automatically rewinds the film, nor that it rewinds it at all, but that it uses the film for a second and third projection, and as many projections as required, without rewinding it at all. The top magazine, or feed magazine feeds from the middle of the reel. 223 148 THE MOTION PICTURE Film reels received from the film exchanges usually are wound with the title end outside. When so received, the reel must be rewound before it is placed in the feed magazine of this "Automatic Rewinder" machine; and indeed, when the film is received with its leader inside the roll, as this machine requires it, the film must be rewound twice, to get it into a roll with a large opening in the mid- dle. Having reeled the film up with a large center opening, and with the leader and title inside of the roll, the roll is dropped into the horizontal round feed magazine, the leader end is taken in the middle Fig. 93. The Rewinding "Standard" Projector of the roll and is passed down through the floor of the feed maga- zine into the film inlet of the motion-head box, passing over the guides provided; the motion-head mechanism then is threaded with care for the upper and lower loop size, as described for the "Stand- ard" machine. Fig. 90, and the leader end is taken into the take-up magazine and attached to the take-up reel, which has a large arbor, so that the film is rewound with a large opening in the middle. Projection is made by crank or motor, the strip of film feeding from the center of the feed magazine and winding up, head in, upon the take-up device. 224 MOTION HEAD 149 AMien the strip of film has been completed, the operator lets the tailpiece run through until it is completely wound upon the take- up reel. He then opens both the take-up magazine and the empty feed magazine, takes the film off of the take-up device without the reel, and places the film without the reel in the feed magazine, starts the inside end of the film down through the floor of the feed maga- zine and over the guides, threads up the motion-head mechanism, attaches the leader to the take-up mechanism, closes up the doors, and is ready for projection again, repeating as often as his program requires. \Yhen a program of two or three reels is being run, one reel after another, the old reel is lifted from the take-up device and placed flat in a metal storage box, placed upon the shelf flat to keep the open roll or hank of film from collapsing, and the new hank is dropped into the feed magazine. Xo rewinding ever is required except to get the film into proper form for the feed magazine when it is received from the film exchange or factory, and to wind it up again upon a small arbor to pack it in the small shipping box in which it was re- ceived from the exchange. This machine is no longer offered for sale by the manufacturers, and theaters equipped with them may have the special magazines replaced with the later type, requiring rewinding, if the automatic rewinding feature is not entirely satisfactory. THE SELIQ POLYSCOPE The old style Polyscope, made by the Selig Company, has been withdrawn! from the market. It used the pin-shift mechanism con- trolled by two cams on the main driving shaft. The Polyscope projector now sold by the Selig Company is il- lustrated complete in Fig. 94, and its motion head is shoA\Ti in closer detail in Fig. 95, the door of the film gate being opened. The film feeding mechanism is the American standard, three- sprocket, with Geneva intermittent drive. In threading up the film, the feed reel is placed in the magazine on the top of the motion head, the end of the film is taken through the film outlet rollers, and the door of the feed magazine is closed. By finger pressure upon a projecting lug, the presser roller is lifted from the upper constant feed sprocket until the film is placed upon the sprocket and meshed with the teeth. 225 150 THE MOTION PICTURE The frame lever is now framed "down" to take out any slack which might be above the film gate, the film is placed in the track of the film gate with a slight slack above — at least one picture length — then meshed with the intermittent sprocket, and the film-gate Fig. 94. Selig Polyscope Projector door is closed. This causes the guide roller at the top of the door to engage the edges of the film, and presses the pre-sser roller against the intermittent sprocket, both of these rollers being carried by the door. This step in threading might seem at first to require three hands on the operator, but the trick is to hold the end of the film below the intermittent with the left hand, to press the film above the motion-head frame with the long finjjer of the riijht hand and stretch it tight over the film window and along the film track of the gate, then 226 MOTION HEAD 151 Fig. 95. Sclig Polyscope Motion Head 227 152 THE MOTION PICTURE to swing the door shut with the thunib of the right hand, which will be almost engaging the top guide roller of the gate. Now frame "up" and give a little slack in the lower feed loop, then pass the film down into the magazine box, or to the take-up reel if one is userl. The Selig lamp house has the feature of sliding the lamp en- Fig. 96. The Selig Lamp tirely out of the house to make inside adjustments, and to set the carbons. Fig. 94 shows the lamp withdrawn from the lamp house. Before projection is begun, the lamj) is pushed in until the vertical panel at the back of the lamp closes with the body of the lamp house and forms a closed house. The controlling knobs have universal joints, permitting them to pass through very small holes in the back panel of the lamp house, and yet reach and operate their different parts of the lamp in any position of adjustment. Four knobs are provided outside the lamp house, for lateral, 228 MOTION HEAD 153 transverse, vertical, and feed movements of the lamp. The angle of the carbons, either jointly for direct current or separately for alter- nating current, is adjusted by drawing the lamp from the house and working upon adjustments normally inside of the lamp house. The Selig lamp is illustrated in detail in Fig. 96. THE EDENQRAPH PROJECTOR In the general design of this machine, the manufacturer has planned for the most direct film path possible, and for the separa- tion of the film path from all entangling mechanisms as far as it is possible to do so. The path of the film is "in the open air" as com- pletely as it is possible to make it, from the outlet of the feed maga- zine to the inlet of the take-up magazine. Fig. 97 shows the Eden- graph in general view. In Fig. 98 a close view of the motion head and magazines of the Edengraph are given, from which also the threading of the machine may be seen clearly. After placing the feed reel in the upper magazine, the leading end of the film may be inserted into the outlet valve by slipping it through the slot in the side of the valve; it will then be properly placed be- tween the two pairs of rollers, for there are four rollers in each of the film valves. The film is now carried around the upper sprocket, which is as close as can be to the upper film outlet, and is pressed to the upper sprocket by the single presser roller. The film is then taken over the flanged guide roller at the top of the film gate, the film gate is opened, and the film is carried down the film track to the intermittent, leaving a sufficient slack at the top of the gate for the top feed loop; the gate then is closed. The film is now brought around the lower sprocket and taken into the take-up magazine through another four-roller film valve and attached to the take-up reel in the usual manner. A turn of the crank will show that the take-up and feed elements are working properly, when all doors may be closed and the machine is ready for projection. The film is rewound by a separate rewinder. The gears of the motion head are all contained within the box- like frame, but are accessible by taking off the side of the box next to the stereo lens, first swinging the stereo lens out of the way, as shown in Fig. 99. 229 154 THE MOTION PICTURE Fig. 97. The Edengraph Projector 230 I. MOTION HEAD 155 Fig. 98. Detail View of the Edengrapb Motion Head 231 156 THE MOTION PICTURE Fig. 99. Edcngraph Gear Case of Motion Head 232 MOTION HEAD 157 Fig. 100. The Edengraph Motion-Picture ^Mechanism with the Film Gate Swung Open on Its Hinge Fig. 101. The Edengraph Geneva Box 233 158 THE MOTION PICTURE Fig. 102. The Edengraph Lamp Adjusted for Alternating Current Fig. 103. The Edengraph Lamp Adju.sted for Direct Current 234 o -51: OS . a ■? ? . c a Spa o - » o = ^ w 1^2 MOTION HEAD I59 The film gate door of the Edengraph is pivoted at the bottom, instead of at the side as is customary; the argmnent is that the pres- sure upon both edges of the film will be e(jual witli this method of construction. The two fire shields are attached to the film gate door for the protection of the upper and lower feed loops. This detail is shown in Fig. 100. The intermittent drive is the Geneva type of mechanism, en- closed in an oil box, the intermittent shaft projecting through the wall to pass outside of the motion-head frame to the film gate, Fig. 101. The Edengraph lamp has three control knobs, the diagonal knob being carbon feed, the upper level rod being the adjustment for height, and the bottom knob being the adjustment for distance from the condensers. The adjustment for angle and the adjust- ment to the right or left is made inside the lamp house. Two views of the Edengraph lamp are given in Figs. 102 and 103, the lamp in Fig. 102 ])eing shown atljusted for alternating-current arc and the one in Fig. 103 for direct-current arc. THE LUBIN PROJECTOR Lubin's "Marvel" is shown in general view in Fig. 104. A near view of the motion head, with the film gate door open, is shown in Fig. 105. In this device, the flame shield is pivoted to the operating table below, and attached to the gate door above. The safety shutter is operated by a friction clutch, which must be kept clean and free from oil. To set up the machine, the motion head is fastened to the table by means of the thumb screw which also holds the front leg of the table. The belt from the motion head to the lower magazine take-up shaft is crossed to turn the shaft in the proper direction. The automatic fire shield must stand so that if the lamp house is in line with the mechanism the fire shield stands straight between the two. Hook the fire shield to the lamp house by means of the adjustable rod. AMien in proper position, the fire shield must al- most touch the table. Slide the electric lamp and the stand provided for it into the lamp house and fasten by means of the shortest handle, which also serves to raise or lower the lamp. 235 160 THE MOTION PICTURE The condensers are placed in the holder with the round sides facing each other. Fig. 10-1. General View of the Lubin Projector To thread the film, push the lamp house to the left. This opens the fire shield and leaves the motion-head mechanism free. Place the full feed reel in the upper magazine. The film must unwind 236 I MOTION HEAD 161 toward the left, and the emulsion or dull side of the film must be to- ward the lamp house, the figures, of course, being upside down, or heads down, and the leader or title being on the outside end of the Fig. 105. Detailed View of the Lubin Motion Head reel. Pull the film through the rollers of the flame-trap or film out- let attached to the lower part of the magazine. Close the door of the magazine and fasten with the catch. Bring the film to the top 237 162 THE MOTION PICTURE sprocket, press downi the rollers underneath, lay the film around the right side of the sprocket and close the rollers to press the film against the sprocket, seeing that the teeth of the sprocket mesh properly with the holes in the film. Open the film-gate door. Now press down the framing lever fully. This lowers the framing carriage. Bring the film between the door and the tension plate of the gate, carrying it accurately down through the film guide of the film gate, and close the door. This door may be closed before adjusting the film to the intermittent sprocket. Pull up the film, so as to leave a loop big enough to place over your thumb between the top sprocket and the door rollers. Turn the fly wheel by hand until the middle sprocket — intermittent feed sprocket — starts, but before it moves any distance stop and open the presser rollers and place the film upon the middle sprocket meshing it carefully with the teeth of the sprocket, and letting the presser rollers down upon it to hold it in place, the rollers pressing the film to the hubs of the sprocket teeth. Now raise the carriage fully by means of the framing lever. Open the presser rollers of the bottom sprocket and place the film around the sprocket, but leave just loop enough to touch the back guard, putting the teeth of the sprocket properly through the film. Close the rollers, so that the film now lies between the bottom sprocket and the rollers, the rollers being on top. Push the film through the two rollers in the bottom magazine, turning the handle of the motion head to give a sufficient slack to reach the arbor of the take-up device. Attach to the arbor in the usual way, take up the slack by turning the take-up reel by hand, then turn the crank a part of a turn to see that the take-up is work- ing properly, and close the lower magazine door. After everything is in place, turn on the light, but be sure that the fire shield is closed. ^Vhen starting projection, press the main crank and handle somewhat toward the left. This will bring the friction clutch into action. Also notice before every projection of a reel that the automatic fire shutter is working properly. Should the fire shutter refuse to work, there is either oil or dirt in the fric- tion clutch to which the chain is attached on the main shaft gf the handle. Never oil the friction clutch. In case of dust or oil com- 238 MOTION HEAD 163 ing into this clutch, wipe it out clean and dry. Now open the door of the fire shield, turn the handle and proper projection may he made. GENERAL NOTE Before taking the instructions for any particular machine as final, remember that there are many general rules which apply to all machines, and these have been discussed under the subject of the motion head and motion-picture projection in general. 239 t MOTION HEAD FART III TALKING PICTURES The histrionic stage holds a mirror up to nature. That is the text upon which a preliminary description of the art of the talking picture will be based. The motion picture reproduces, as a mirror would reproduce, the histrionic stage; the actors of the drama are voluble of lip and expressive of face and gesture, but they are silent. The motion-picture scene of the waterfall shows the tossing waves and the plunging masses of turbulent water, but the splash of the rapids and the roar of the cataract are not heard. In the motion pic- ture of the rural sunmier landscape the trees may wave their boughs upon the picture screen and the atmosphere of the grove seems almost to pervade the theater, but the murmur of the breeze in the tree tops and the buzz of the cicada are not there. The motion picture truly holds a mirror up to nature, but it is only an ordinary looking-glass giving back the scenes, but not the sounds. The talking picture promises nothing new from the picture screen, but promises to supply the missing sounds, to couple the senses of sight and hearing, and to make the reproduction of the subject complete, at least so far as drama and vaudeville may be concerned. NATURE OF THE PROBLEM To get a close understanding of the problem of the talking picture the experimenter may assume a position before a mirror, and, being in such position in fancy or in fact, he may talk, sing, laugh, or dance before it. If he should talk or sing, the lip movements would be reflected by the mirror exactly as produced by his lips. These movements he will see in the mirror. At the same time, he will hear his owti voice, but not in the mirror or from the mirror. If he should dance, the faithfid mirror gives back every movement to his -eye, but does not give back to his ear the sounds of his feet upon the floor; those sounds are heard by his ears directly Copyright, 191 1, by American School of Correspondence. 241 166 THE MOTION PICTURE Now let the experimenter bring into his servnce the motographic camera. Again, he may talk, sing, laugh, or dance. The mirror is replaced by the sensitive photographic film, which receives the lio-ht much as the mirror did, but which records it as received. By processes of photographic development and printing and then by projection, the motographic film is made to give its record to vision, long after the experimenter has ceased talking, singing, laughing, or dancing. AMiat is this projected motion picture, recorded by the moto- graphic camera and the sensitive photographic film? Just what the mirror gave back — the scene but not the sound. The photographic film was sensitive to light but not to sound, and recorded light but not sound, ultimately reproducing its record in light but not in sound. Recording Sound. The phonograph, or graphophone, is hardly older than the motion-picture camera. Like the motion-picture camera, the graphophone has a recording surface but the surface is of a different nature and the method of recording upon it is differ- ent. The camera record surface makes a record of light; the grapho- phone record surface makes a record of sound. Like the camera, the graphophone may be made to give back its recorded message in the language of the record, light for the one and sound for the other. How easy it seems for the experimenter to procure both a camera and a graphophone, and to talk, sing, laugh, or dance before both of them and then have both of them reproduce their respective records at the same time, whereby not only the sight but the sound of the speech, song, laugh, or dance may be reproduced at will from the inert records for the entertainment of the experimenter or others. With the first experiment at this duplex making of records, the feature of synchronism will become a prominent and probably an inharmonious one. Synchronism. When the experimenter stood before the mirror, he heard the spoken word at the same instant that he saw the lips in the mirror move. He heard the sound of the step of the dance at the same instant that he saw the mirrored foot strike the floor. But in the reproduction, such a difference! The graphophone begins the song before the pictured man upon the screen has opened his lips; or the picture shows the experimenter singing or dancing 242 II MOTION HEAD 167 in a manner familiar to all theatergoers, and in the midst of the motion picture the graphophone begins a song or a clatter which seems to have no relation to the picture. Synchronism is lacking. The experimenter now has learned that liis two records must start together, or in proper relation, and must keep together, for when they are only a second apart in time, they are more ludicrous than when so far separated that they seem to have no relation at all. The graphophone has not been perfected for the minor soimds of nature. The human voice is about the limit for the sound record. Voices an^i~musical instruments are the standard repertoire of the talking machine, other records being the exception rather than the rule. This limitation of the graphophone limits the combination sight-and-sound entertainment to dramatic and vaudeville incidents, dancing and singing. The tremendous demand for motion pictures which do not talk, the large number of theaters projecting motion pictures as the prin- cipal part of their program, and the avidity with which the theater manager investigates novelties to please his patrons, all indicate that a successfid talking picture with a rehable system of projection to maintain s\Tichronism between picture and speech would meet with a royal welcome and bring a rich reward to its promoters. Thus it has become the dream of inventors to combine those two devices, the motion picture and the graphophone, successfidly, but always the stumbling block has been synchronism. Not only must the picture film and the talking record be capable of synchronism, but means must be provided whereby they may be kept in s\Tichronism either automatically or with a minimum amount of skill on the part of the theater operators. Synchronism, therefore, must be considered in two phases : first, making the photo- graphic record and the sound record in such relation that reproduc- tion in synchronism is possible, and, second, reproducing them properly as intended in their manufacture. If the graphophone record and the picture film must be pro- jected at the same speed to keep them in unison or in synchronism as required, may not both be put in a single machine equipped with sound reproducer and a projecting lantern? In toys this is practicable, or in a home exhil)ition, but in a large theater thejnotion pictures are projected from behind the audieiiCe,''passing over their heads 243 168 THE MICTION PICTURE to the picture screen and being appreciated by the audience only as rays passing from the screen to the eye. If the graphophone were located with the projecting machine for the pictures, the sound would come to the audience from l)ehind, which would be unnaturaL_ Instead, the sound must come from the front of the theater. This limitation compels the location of the phonograph at or near the picture screen, while the projection machine must be at the back of the theater. Onlv bv projecting the pictures upon the back of a translucent curtain and permitting the graphophone to talk through the cur- tain may the two devices be located together. The two machines, motion-picture projector behind the audience and graphophone in front of the audience, may be kept together in speed bv some relation of propelling or controlling means. It is in this feature that inventors have beeu most active, and it is in this feature that the differences will be found in analyzing and comparing ,'^'the different "talking picture" machines and systems offered and to be offered upon the market. Length of Records. Theoretically, there are no limitations of length of a talking picture, for the second talking machine may be started just as the first talking machine is stopped, and the third disk of the series may be placed upon the first talking machine to be started just as the second one has stopped. Likewise, with two pro- jecting machines, the second reel of film may be started just as the first is stopped, and the first projecting machine then may take up the third reel just as the second is finished. With a single talking machine and a single projecting machine, the limit is reached with the talking machine first. The maximum talking record m^America is^ thei^^iTrdrTiiskrTTiTtniiig fixajninutes. The 10-inch disk runs three to four minutes, while the "four-minute" cylinder record lives up to its name, running four minutes or longer. European records running fifteen to twenty minuj;es have been reported and will be of value in the talking-picture art when adopt- ed for that purpose. Cinephone films are offered upon 10-inch disk records, each accompanied by" loO to 2.')0 feet of motion-picture film. The possibility of the longer talking picture is assured, for it has been done. As for long, continuous sound records upon a num- ber of disks, there are already offered to the general public for use 244 II MOTION HEAD 169 in private talking machines, records for_t he com pIet£__Qperas of "Faust" and "William Tell." These records may have motion pictures fitted to them, according to the methods of the manufacture of talking pictures, or records of equal length may be made from the same or other subjects, complete with picture films. CLASSIFICATION All of the suggestions as yet made for producing talking pic- tures may be brought under one of the following three classes: (/) The two machines are driven from the same source of power and are so related to this source that their speed of reproduc- tion is identical. (2) The two machines are so related that one drives the other or controls the speed of the other directly. (J) Index hands or the equivalent are provided for the two machines, and an attendant, by constant supervision, keeps these index hands in proper relation. (1) Unitary Machines. In the unitary machine, the two machines, projector and graphophone, are built together and are driven by the same main shaft of the combined machine, which may be turned by a crank or motor of any kind. In such a device, it is necessary to be able to secure exact synchronism at the starting of the picture and sound records, or to provide some means of adjust- ing in order to enable the operator in charge to get his picture to catch up with his graphophone, or to permit his picture to slow down to let the graphophone catch up with the picture. Long Main Shaft. An invention which places two machines in the first class is the system of providing a long main drive shaft under the floor of the theater, gearing it at one end to the graphophone and at the other end to the projecting machine. At the projecting machine end, a clutch should be provided, and if the start is not made in synchronism, so that an adjustment is required, the operator may throw out the clutch and turn the projector l)y hand faster or slower until he gets the picture in synchronism with the speaking record; then he may throw in the clutch again, and the main shaft, driven by a constant-speed motor of sufficient power, keeps the two machines in constant speed relation, projecting their two records at the same speed and in synchronism. 245 170 THE MOTION PICTURE ^Mien a splice in the film passes, where a few images have been cut from the film in repairing it, the picture film wilLrun^ead of the graphophone record and the operator must detach his projector from the main drive shaft until the two records are brought into synchronism again. A new film should run in synchronism from start to finish under this method of driving, but an old film which has many breaks and splices becomes harder and harder to operate Fig. 105. The Photophoue. A Unitary Talking- Picture Machine in synchronism as its splices increase. A matter of three to six pic- tures cut from the film— one-fifth to two-fifths of a second in time of projection — is sufficient in most talking-picture records to render them very noticeably out of synchronism. Synchronous Electric Motors. There is an electric motor which is called a synchronous motor because when carrying its load it runs always in exact accordance with the speed of the d}Tiamo which is furnishing the electric current for driving the motor. It is a motor operated by an alternating current, and its speed always is propor- tional to the speed rapidity or frequency of alternation of the current which drives it. When two such motors, just alike, are placed in 246 MOTION HEAD 171 service upon the sjime power circuit, driven by alternating current from the same central station electric dynamo, it follows that each will run at exactly the speed of the other. With one such motor driving the graphophone and another upon the same power mains driving the projecting machine, the speed of the record of the grapho- phone and projecting machine will be identical, proper speed gear- ing to the motors being provided. Any slight change in speed of the electric generator at the power station which is supplying the current for the motors, which of course would result in a slight change in the frequency of the current upon the power mains, is equally effective upon both the graphophone and the projecting machine, so that th^i two machines always move in unison, keeping the reproductions of their records in synchronism, if the records have been made properly. Illustration. In the unitary machine, shown in Fig. 105, the motion head of the projector portion of the apparatus is built upon the support for the graphophone horn. The moving parts of the motion head are driven from the graphophone motor which turns the flat disk record under the reproducing needle of the talking machine. It is necessary only to set the graphophone needle to a marked point upon the talking record disk and to luring a marked picture image into the film window of the motion head, then start the motor. To produce a compact combination device without permitting the horn of the phonograph to interfere with the beam of light of the projected picture, the lenses are arranged to project the pic- ture through the horn, as shown in Fig. 105. In this device if the motion head be disconnected from the graphophone motor, a crank may be attached to the motion head and the skill of the operator then may attain and maintain a synchron- ism which approaches pei-fection only by the degree of skill of the operator. Two machines driven by the same source of power are shown in Fig. 106. The source of power in this instance is the operator's arm turning the crank in the projection room at the upper left- hand comer of the figure. The crank is attached to one of a pair of bevel gears in the operating room, and thus drives the vertical rod extending down through the floor of the operating room to a point below the floor of the theater. There, it transmits its power to the 247 172 THE MOTION PICTURE long horizontal main shaft extending under the floor of the theater to a point under the graphophone. The graphophone takes its power from this long horizontal shaft by means of a short connecting vertical shaft. Thus the projecting machine and the graphophone are driven by the same crank through an arrangement of gear wheels and shafts. Any variation in the speed of the graphophone will change the pitch of the sounds being produced^ a result which cannot be per- mitted in reproducing musical records, and which woiild be very Fig. 106. Talking Picture Reproduction by Two Reproducers Driven from a Long Power Shaft objectionable in any sound record. On the other hand, the motion pictures must be projected at about the speed for vVhich they were intended when made. This distinction exists, however, that while a small variation may be permitted in the speed of the motion pic- tures, no variation at all should be permitted in the speed of the graphophone reproduction. Hence, the graphophone must be driven at a speed as nearly constant as can be obtained by an acceptable motor, and the speed of the motion picture must be varied to bring the two reproductions together whenever for any reason or by any aci'ident they lose their relation of synchronism. A splice upon an injured film will cut out a few images. When- ever this .splice in the film passes through the motion head, the motion- 248 MOTION HEAD 173 picture film will begin to project its picture record ahead of the sounds from-the-^aphophone, and the projector must be slowed down in speed until the graphophone catches up. Should the grapho- phone needle "jump a thread" or Ijy any accident or a defect in the, record fail-to follow the record accurately, the projection operator must turn the projector faster or slower to vary the speed of the* motion picture until the two records again are being produced in synchro- nism. It will be seen that in Fig. 106, to adapt the arrangement to practical work in a theater, the handle must be geared permanently to the shafting, and the motion head, of the projection ma- chine must have such a relation that it may nm slower or faster in order to be capable of adjustment for synchronism. {2) Dependent Machines. In this class of reproducing mechanisms for talking pictures, one machine must drive the other, or must control the other. As the variation in speed due to control, if any, must be impressed upon the picture projector and not upon the graphophone, the problem resolves itself into a constantly-driven grapho- phone either driving or controlling the picture projecting machine. Such a pair of dependent machines is shown in Figs. 107 and 108, the former show- ing the graphophone, and the latter, the picture projector motor. The machine illustrated is one brought out in Paris and in- vented by Captain Couade. Thq crank seen in Fig. 107 is the crank for winding up the motor of the graphophone, and not for turning the graphophone directly. This graphophone runs in the usual manner, and may be quite an ordinary type of talking machine, with the addition of a commutator for electric current which changes a constant potential to a system of intermittent potentials upon different circuits, the relation of the potentials produced by the com- FiK. 107. Graphophone for Talking - Pictiu'e Reproduction, Sending Current to Distant Pro- jecting Motor through Electric Cable , , 249 174 THE MOTION PICTURE mutators of the graphophone being likened to the related potentials of a three-phase alternating current. The electric commutator is inside the graphophone cabinet, the electric terminals and switches being seen in the figure upon the outside of the cabinet. The wires which lead from the graphophone downward carry the electric potential impulses created by the graphophone commutator. In Fig. 108 is shoTsii the motor for driving the motion-picture projec- Flg. 108. Motor for Picture- Projecting Machine for Talking Pictures, Driven in Sj-nchronism with the Grapliophone by Current Received Over an Electric Cable tion machine. This figure does not show the projection machine, nor is it necessary to do so, since any projection machine may be used to project the picture film, provided only it is coupled to this special motor and driven by that motor at exactly the speed which the graphophone dictates by means of its electric commutator. The electric cable rising from the bottom of P'ig. 108 to terminals upon the side of the motor is connected at its other end with the commutator of the distant graphophone, located near the picture screen of the theater. S50 MOTION HEAD 175 In operation, the motion-picture film is placed in the film gate and framed with a marked image in the film window. The needle of the graphophone then is placed upon the record disk at a marked point. These two marked points, one on the picture film and one on the sound record, were obtained in manufacture and placed upon the records when the records were made. They are points to which the records are in unison in time with reference to the light and. sound of the subject. The phonograph now is started and dri^■en in the usual manner. The motion head of the projection machine, driven by the motor, gains speed as the phonograph gains speed, until both are running fully. If the projection machine is provided with an automatic fire shutter, the shutter will be lifted and permit the projection of the picture upon the screen as soon as sufficient speed has been attained. In this device, the motion-picture projector is started by the graphophone, and it is run with the graphophone, stopping with the graphophone. The power for running the motion-picture pro- jector is not created by the graphophone, nor by its motor, but it is so controlled by the commutator of the graphophone as to drive the motor and the picture machine at the required speed. The motor is so constructed as to be unable to turn under the influence of any direct current which may leak to it through the graphophone com- mutator while the graphophone is at rest. The operator at the pro- jection machine must note any lack of synchronism and correct it, after v.^hich the records will stay together. (3) Dial=Regulated Machines. In this class of reproducing devices for talking pictures, the talking machine and the picture machine are separate, and each has an index hand. The index hands need have no direct relation to each other nor any direct connection with each other, but each serves to show the speed at which its associated machine is being driven. The graphophone being driven at a constant speed, its index hand will revolve at a constant speed, and the projection machine operator then nuist turn his crank at such speed as will make the picture machine index hand keep up with the pace of the graphophone hand, and not run ahead of it. Greenbaum. In Fig. 109 is shown a diagram of the system and some detail of the apparatus of the Greenbaum device. In the figure, 231 176 THE MOTION PICTURE at the upper left-hand comer, is shown a commutator upon a shaft which is mounted in connection with the shaft of the motion-picture projector. At the upper right-hand corner of the figure is shown a similar commutator which is mounted upon a revolving shaft which is associated with a shaft of the graphophone. The device forming Fig. 109. Greenbaum Mechani.sm for Synchronizing Talking Picture the lower part of the figure is a dial which is mounted in the operat- ing room, in front of the operator who is turning the crank of the inotion-j)icture projector. Upon the dial are seen two index hands, 24 and 29. The hand 2^ is driven by the picture projector and the hand 29 is driven by the graphophone. When the two machines 252 MOTION HEAD 177 are running in synchronism, the two hands will maintain a constant angle between them, preferably being together, that is, the hand ^4 should cover the hand 29. By reason of splices in the film, or by ac- cident, the hands may become separated, in which case the angle be- tween them must be kept constant by the projection-machine operator. Electric incandescent lamps also are provided — as shown by the circles 50, 51, and 52 in the figure — and are so arranged that lamp 51 will glow when pictures and talking record are in unison; lamp 52 will glow if the pictures are behind time; and lamp 50 will glow if the pictures are ahead of the talking record. The lamps, as well as the hands, serve to guide the projecting operator to keep the two records in synchronism. The mechanical arrangement of parts in the Greenbaum device is as follows: In the case 1, the two electromagnets 2 and 3 are mounted. Electromagnet 2 is connected by electric wires 12 with the electric commutator device of the shaft ^ pertaining to the pro- jector, in such manner that every time the commutator of the shaft 4 closes the electric circuit an impulse of electric current will flow from the battery A through the wires 12 and the commutator and the magnet 2 to cause the armature 10 of the magnet 12 to be attracted. This, by the action of the pawl 17, drags the ratchet wheel IS down one tooth; this ratchet wheel in turn by a pair of gear wheels drives the shaft of the hand 24, moving the hand 2Jf a short step over the dial 30. One such step of the hand ^4 i^ made for each revolution of the shaft 4 of the projector, hence the speed of the movement of the hand 2Jf is a measure of the speed of the projector. In like manner, electromagnet 3 is connected by electric wires IJf and 15 with the electric commutator device of the shaft 8, per- taining to the talking machine, in such manner that every time the commutator of the shaft 8 closes the circuit an electric impulse will flow from the battery B through the wires I4. and 15 and the com- mutator and the magnet 3 to cause the armature 16 of the magnet 3 to be attracted. This by the action of the pawl 17 drags the ratchet wheel 19 up one tooth; this ratchet wheel in turn by a pair of gear wheels turns the tubular shaft of the hand 19, moving: the hand 29 a short step over the dial 30. The hands 24 and 29 move in the same angular direction, and when the records are being rendered in unison they move at the same speed. 253 178 THE MOTION PICTURE It is necessary, in starting the devices to render a talking pic- ture, to place the film in the motion head with a marked image in the film window, to place the needle of the talking machine upon a marked place in the record, then to place the two hands of the indicator together. After that, if the hands are kept together, the records will be kept together as the records are reproduced. The passing of splices where images have been cut from the picture film will cause the hands to separate if sjTichronism is maintained by the operator, since the projection operator must slow down his machine to regain synchronism, after which the relation of the hands is maintained at the new angle. Cinephone. The cinephone system of talking-picture produc- tion will appeal alike to the projection operator and to the practical theater manager, and for the same reason, namely, that it has a minimum of special apparatus in the theater, and it requires the least specialization of skill on the part of the projection operator. The cinephone as offered to the public is in substance only an attachment for a well-known type of talking machine. As built it is a quick-starting talking machine having an unusually heavy spring which permits it to obtain its full speed and volume of sound almost instantly upon the release of the ordinary brake which sets the disk record revolving. It may be used for ordinary disk records for enter- tainment between pictures, or for illustrated songs, without the cinephone motion-picture films, which in connection with the talk- ing machine produce the talking pictures. The cinephone talking machine stands at the side of the picture screen and faces the audience and the projection operator. It has an illuminated dial upon its front face, upon which there is an illu- minated revolving hand. The course of the hand is marked by four green bullseye lamps, readily discernible by the projection operator in a darkened auditorium, even at a distance of two hundred feet. The illuminated dial and hand are for the purpose of register- ing the exact speed at which the talking machine is operated. A similar dial and hand are photographed into the motion-picture film, the hand of the motion-picture film traveling over a circle which is marked by four white bullseye spots upon the picture screen. This second dial and hand appear in the lower left-hand corner of the film picture and of the screen when the picture is projected upon it. 254 MOTION HEAD 179 As the picture is shown, the dial hand in the screen and the dial hand upon the front of the talking machine both move in the same direction and at the same speed. The projection machine is operated at a speed calculated to keep both dial hands at the same point upon the dial circumferences at all times. So simple is this, that anyone can be taught to produce cinephone synchronism in a few moments. Any projection machine already in use may be used under this system of synchronism and any ordinary operator can master the additional detail quickly and show a finished talking picture. There are no connections, electrical or otherwise, between the cinephone talking machine and the picture screen, nor between the cinephone talking machine and the projection machine. The operators required are the projection-machine operator and the pianist or other musician or regular attendant of the theater to make the change of records and rewind the talking-machine motor, and to start the talking machine when the starting flash is received from the picture projector. It is the intention of cinephone design that the number of employes of the theater need not be increased, and that no special skill be required of any of them. MANUFACTURE The theoretical method of recording action and speech, by locating a recording graphophone and a motion-picture camera properly near the speaking actor, has limitations. The graphophone must be near the spe^er, or it will not record the speech, while the camera requires some interve ning disj^^ance in.9j:der-.to-;se€ure a -proper rendering of _tlie--pietTiTeI ^et the graphophone must not appear as '\ an object in the picture obtained by the camera. Small Subjects. A very delightful and thoroughly successful talking picture, or better "singing" picture, is that of a can ary-bird singing in its cage. The actual area pictured by the camera is only about a scjuare yard, with the bird near the center, so that the grapho- phone recording horn could be brought within 18 inches of the bird without appearing in the picture made by the camera. In this man- ner, the two records could be made simultaneously, and when repro- duced they are capable of absolute unison when properly synchronized and uniformly driven at the proper speed. 255 180 THE AMOTION PICTURE A talking picture of a "laugh" in which the laughing face is taken by, the camera afcTose^range, to fill the entire space of the pic- ture image, being then projected to fill the entire picture screen, may be made in the same manner. Even in the case of a monologue by a single actor, where the actor standing before the camera fills the picture image space to the top line, the limit of the field of the camera may be determined very accurately and the recording grapho- Fig. 110. Producing the Talking Record for a Talking Picture phone horn may be j)laced just above the limit of vision, that is, just above the picture as projected upon the screen. Large Subjects. In producing a talking picture where several actors are involved, the method of manufacture is to make the talking record first, and then fit a motion picfuf e~to it^ To ^J« this, the actors are well drilled in their parts, so that they will be able to produce the performance twice, once in sound for the sound record and once in action for the picture record. The actors being thus trained, the sound record is produced without any reference to what the appearance of the actors may be while producing the record, the end desired being only that the best po-ssible sound record be obtained. 256 MOTION HEAD 181 A group of actors producing a sound record is shown in Fig. 1 10. They are standing compactly grouped, facing the recording grapho- phone. The stage director stands coatless above them. In Fig. Ill, the next step of the process is shown, namely, that of training the actors into unison with the sound record alreatly produced. In the foreground is seen the horn on the talking machine. It is rendering the sound record. Before the horn stand the stage director and a group of the actors. The actors are repeating the words which they Fig. 111. Drilling the Actors before the Graphophone to Attain Unison with the Talking Record before Making the Picture Record of a Talking Picture used in making the sound record, repeating them in unison with the talking marhtiie, and at the same time suiting the actions to the words. As yet the camera has not been brought into use, for the sound record may be made indoors, and the rehearsal for action may be' made indoors as well, but the making of the picture must be done in the field before a suitable background or in the studio in a proper stage setting. Talking=Picture Camera. The combination camera and talk- ing machine for the final step, namely, the making of the picture record, to fit the talking record, is shown in Fig. 112. At the left is the reproducing graphophone; at the right is the motion-picture 257 182 THE MOTION PICTURE camera. Both are mounted upon tripods, for use in field or studio. Connecting the two machines is a driving shaft, and upon the tripod with the camera is mounted an electric motor for driving the shaft. This combination machine is started, the actors act and speak in unison with the talking machine, and are photographed by the camera. Even the words of the talking machine must be repeated in unison with the machine, that the lip movements of the actor in the motion picture may be synchronous with the spoken words of the talking machine. The photographic negative is developed and prints are made. The starting point now is marked upon the sound record and upon Fig. 112. The Rerordins Motion-Picture Camera Coupled to the Reprotlucius Grapliophone for Producing the Picture Record of a Talking Picture the picture film, and the two records are ready for delivery to the theaters for tlie production of talking pictures. REPRODUCTION OF TALKING PICTURES Operation of the Cinephone. The picture screen and talking machine of a theater with the cinephone in operation are shown in Fig. 11. 'j. Note the dial upon the talking machine, and the similar dial ill the lower left-hand corner of the picture upon the screen. Note 258 I 184 THE IMOTIOX PICTURE also that the hands upon the two dials occupy the same relative positions. Starting in Synchronism. The pianist assists the projection operator by managing the talking machine. The talking machine is turned slowly by the motor or by hand until the index hand is in an upright position, pointing to the top lamp of the four which sur- round its dial and which appear in Fig. 113 as four black spots, above, below, to the right, and to the left, respectively, of the dial on the front of the talking machine. The disk record then is placed on the carrier with its marked point under the needle. A groove is cut in the disk to guide the needle to the starting point of the record. The motor of the talking machine is wound and the talking machine is ready for action. During this process, a small incandescent lamp has been burning upon the top of the talking macliine; when all is in readiness, this lamp is turned out by the pianist as a signal to the projection operator in the operating booth that the talking machine is in readiness. The projection operator threads his leader through his motion head in the usual manner, there being no special marked points to be observed, and begins projecting the film at the cinephone speed of eighteen pictures per second, or about sixty-six feet per minute — a speed one-third greater than the usual picture speed. All initial leader and title having passed, and the portion of the picture having been reached where the talking machine is required, there appears upon the picture screen, for a fraction of a second only, the words, ' The Cinephone." This is the "starting flash," usually stained yel- low and, therefore, called the "yellow flash," which is the signal for starting the talking machine. The pianist, who has been wait- ing with hand on starting brake of the talking machine, draws the Ijrake away from the record carrier. The talking machine starts at full speed, and the index hand of the talking machine also starts revolving. At the time of the starting flash, the index hand of the picture film is vertical — note the lower left-hand corner of Fig. 113 — and so corresponds with the vertical position of the index hand of the talking machine. yiaintaiiring Synchronism. The operator turns the projecting machine at the proper speed to keep the two index hands together, and the two records will remain in synchronism through the entire 260 MOTION HEAD 185 picture. The cinephone speed is faster than the ordinary picture speed, the cinephone film running fifteen minutes to the reel while the ordinary film nms twenty minutes to the reel, but the ordinary pro- jecting machine will stand successfully the strain of the somewhat higher speed. The index hand for the picture screen dial is photographed into the cinephone picture film, and requires nothing special upon the projection machine for the pro- jection of the index hand. Splices are self- correcting in the cinephone film, because when a few images are cut out of a strip of film, the index hand for those images is cut out also. The index hand makes one revolution upon the picture screen for every 14 feet of picture film. This gives the hand a speed of revolution of about four and three- quarters turns per minute, or one turn in about thirteen seconds, the talking-machine hand having the same speed also. If, by some accident, the projection operator is compelled to cut out a piece of cinephone film, say even as much as 3 feet of it, the splicing of the film will cause a jump in the pictures which will take them out of syn- chronism with the talking machine. In such a case, the index hand upon the picture screen will appear to jump also, just the same as any other moving object upon the picture screen. For a 3-foot loss of film, the index hand will jump a quarter of a revolution, and be a quarter turn ahead of the calking-machine index hand ; the projec- tion operator then slows down his motion head until the talking-machine hand catches 114. A Specimen of Cinephone Film 261 180 THE MOTION PICTURE up for the loss, and witliin ten seconds the synchronism will be re- stored for the loss of a yard of film. Ordinary splices, where but from one to six of the little pictures are lost, pass without notice, beincf almost instantly and unconsciously corrected by the operator, whose eye is constantly upon the two hands. In case the talking machine, because of a defective machine, a defective needle, or a defective record, should "jump a thread," the projection operator will notice it, turning either faster or slower until synchronism is attained by letting the index hands separate, then turning at the standard speed until the end of the picture, keep- ing the index hands steadily apart at the distance caused by the loss or gain of the talking machine. With a talking-record disk driven at seventy-eight revolutions per minute, the usual speed for Victor records, a loss or gain of a thread upon the record makes a difference of one-sixteenth of a revolution of the index hands. That is to say, the gear between the revolving record and the index hand is about sixteen-to-one. The excess speed of the cinephone film, 66 feet per minute in- stead of oO feet per minute for standard projection, will enable the operator to turn his motion head for cinephone film at three-quarter speed without causing an objectionable flicker upon the picture screen, thereby enabling the talking record to again come into perfect accord with the picture film, that is, enabling the index hand of the talking machine to catch up with the index hand of the picture screen. A specimen of cinephone film is shown in I^ig. 114, showing the index dial and hand photographed into the lower left-hand comer of each of the images. COLORMOTOQRAPHY Color photography with the fixed camera has been an accom- plished fact for several years, but the production of colored motion pictures, in the colors of nature, by photography direct from nature with color-sensitive photographic films, has only lately reached two solutions, one of which is called the Urban-Smith proc- ess and the other the Friese-Green process. Both of these have been exhibited publicly. Other processes are promised, but the promises are as yet unfulfilled. 262 MOTION HEAD 1S7 URBAN=SMITH PROCESS The motion picture itself, the black-and-white kind, utilizes the persistence of vision for the production of motion in the picture, simulating the motion of the subject photographed. The Urban- Smith process utilizes the persistence of vision still further, causing it to produce also color in the picture simulating the color of the subject photographed. Obviously, it would be possible easily to reproduce in blue upon the picture screen a picture which has noth- ipg but blue in the subject photographed; or the same is true of green if the subject had nothing but one shade of green in it; but when the subject has both blue and green, and perhaps red and yellow as well, how shall these colors be preserved separately and combined upon the screen when projected? The Urban-Smith answer to this question is that they may be photographed separately and then thrown upon the screen so rapidly one after another that the eye of the spectator (by the persistence of vision) sees all of them at once. This fundamental principle of record- ing and reproducing the colors of nature has been worked out in a practical form for motion-picture theaters, and has been named "Kinemacolor." The working colors of the photograph have been reduced to two, green and red (or orange). The film when examined before projection appears quite the ordinary black and white film; the color is given to the light rays after they have passed through the film. The pictures are projected at thirty-two per second, or 120 feet of film per minute, a speed about two and one-third times as fast as the usual projection of ordinary motion pictures. Making Kinemacolor Film Pictures. The camera is provided with a double shutter, having two windows, making sixteen revolu- tions per second, while the sensitive film is shifted thirty-two times per second. This corresponds to the number of exposures, since the shutter with its two windows makes two exposures upon the film for every revolution of the shutter. The film is sensitive to light of all colors, and the shutter carries in each of its windows a sheet of colored gelatine, one window being colored green and the other window being colored red or orange. Thus, when the strip of sensitive photographic film has been exposed in such a camera, and subsequently developed into a negative, it 263 188 THE MOTION PICTURE has upon it one picture taken through a green window with green light onlv, and the next picture taken through a red window with red hght only, and so on alternately for the entire length of the film. In addition, a spot is printed opposite each green-light picture to identify the green-light pictures from the red-light pictures, for all of the images in this negative film are merely black-and-white, with- out anv traces of color whatever. From this negative, a positive print is made, exactly as for a black-and-white picture. The guide spots for the green-Hght pic- tures are transferred to the positive print and serve to identify the green-light pictures in the positive. The Kinemacolor film for the projection of motion pictures in natural colors now is complete and readv for the Kinemacolor projecting machine. No coloring what- ever is found in the film. Then how are the pictures to be projected in color? Production of Color. It is generally known that all of the tints and hues of nature can be reproduced by a correct combination of three elementary colors in proper proportions. Red, yellow, and blue usually are used as a set of elementary or primary colors, but orange, green, and violet serve as well. Printing presses turn out daily numberless pictures in colors, calendars hang upon the walls, and picture postcards travel through the mails in flocks, bearing the colors of nature. Yet examine them, and the largest number of them will be found to have met the print- ing plate but three times, once for each of three colors, usually red, yellow, and blue, yet each shows a wide variety in number of colors and a wide variation in tones of each color. It is by the combination of the primary colors in proper proportions that these effects are attained, and the same principle is used on the Urban-Smith process of color motography. On the postcard, the colors will be found to be made up of numberless small spots of the primary colors, intermingled, so that the eye sees none of them separately, but all together, the colors being mingled in the eye. The Urban-Smith process also throws from the screen to the eye the different primary colors in different quantities from the same spots on the screen, and the colors mingle in the eye by the persistence of vision to produce a wide variety of shades and tintings. 264 MOTION HEAD 189 ^^^ ^ Flag in Color. There is presented in Fig. 115 a reproduction of a Kinemacolor photograph of the British flag, a flag which has a bkie field crossed by red stripes, with Hnes of white bordering the red stripes and separating the red and bhie. The spot for identify- ing the green-hght picture is visible in the margin between the per- forations, opposite the second and fourth pictures, counting from the top of the figure. The first and third pictures, counting from the top, are the red-light pictures. For purposes of study, consider that these small pictures are cut apart, that the first picture is placed between two lantem-slide cover glasses of clear glass and projected upon the picture screen, and that the sec- ond picture is placed similarly between the two other cover glasses of clear glass and projected from a second lantern upon the same screen and upon the same spot of the screen, so that the two flags from the two lanterns will be focused upon each other upon the picture screen. The audi- ence will see but one flag, not realizing that the one picture is projected from two lanterns. Note that the second lantern has the picture with the green-light spot, therefore, it has the green-light picture, so slip a sheet of green gelatine over the slide, and at the same time slip a sheet of red (or deep red-orange) gelatine over the picture in the first lantern. This produces a beam of green light from one lantern and a beam of red light from the other lantern, but when they fall upon the picture screen on the clear space all around the flag pictures they will both be seen by the eye at once and the combination will give a white light, or nearly so; hence the flag will be seen upon a white background with the colored beams of light, just as it was before the colored gelatine sheets were put into the lanterns. The same is true of the lines along the edges of the stripes or cross-bars of the flag, but with the bars themselves it is different. Fig. 115. A Kinemacolor Flag 265 190 THE MOTION PICTURE Note that the top image, or red-Ught image, is clear in the cross-hars, while the second image with the green-light spot is dark in the cross- bars. Then the red-light lantern, with the red gelatine color screen and the red-light image of the flag, will project red light upon the cross-bar portion of the flag, but the green-light lantern, with the second or green-light image, which is opaque in the bars, will be unable to project any green light upon the bars of the flag on the screen to change the red light to white, hence the bars of the flag will be seen red by the audience. In the space of the blue field of tlie flag, a little red and a little green light will be projected through the half- tone of the picture film, combining to produce the blue of the flag. Alternate Projection. In the Kinemacolor projecting machine, the red-light flag and the green-light flag are not projected at the same time, as was considered with the two lanterns for purposes of analysis and study, but they are projected one after the other so rapidly that the eye retains the red picture while the green picture is being projected, and then in turn retains the green picture while the next red picture is being projected, thus actually seeing both pictures at once by the principle of persistence of yision. The beam of light from the picture film is colored red and green alternately by a shutter upon the projecting machine similar to that in the camera with which the pictures were taken. The shutter has t\\o windows, one of which carries a piece of red or orange gelatine and the otnei of which carries a piece of gelatine colored green. The green gelatine is in front of the lens while the green- light image is being projected and the red gelatine is in front of the lens while the red-light image is being projected. In this manner, the different images are projected with the color of light which made the negatiye in the camera, and the light giyen to each portion of the screen is of the same color and density as that which made the corresponding portion of the negatiye, which is to say, the same as that which was giyen to the lens or to the eye of the observer by the actual scene motographed. Because of the speed of projection and the principle of the persistence of yisioii, the red-light pictures and the green-light pictures are blended together in all portions of the picture screen at once, so that the eye sees the view as it appeared before the camera, with all its colors and gradations of color and light and shadow in all its dift'erent parts. 266 o M f-i MOTION HEAD 191 Fig. 116 shows a reproduction of a water scene motographed in Kinemacolor film. Kinemacolor Machines. The Kinemacolor film is made to be projected at a speed two and one-third times as great as ordinary black-and-white film. No ordinary machine will stand the strain of such a speed of projection, and a special Kinemacolor projecting machine has been built for the work. The machine should be run by a motor, the power required to drive it at its high speed being almost too great for the arm of the operator, although a short length or a single reel of Kinemacolor may be turned through by hand. A reel of one thousand feet of Kinemacolor film runs but eight minutes on the picture screen. Let any operator try to turn a full reel through an ordinary projecting machine in eight minutes and an idea will be had of the power and speed required of the Kinemacolor projector. The Kinemacolor projector is fully adapted for the projection of ordinary black- and-white, 50-feet-per-minute film, merely by removing the color screen, or shutter having the colored windows, and then turn- ing the machine at a proper rate of speed for fourteen images per second instead of thirty-two. All of its parts are similar to the gener- ally known projecting machines of America, except the intermittent mechanism for the shift of the film, and the removable color shutter. The machine when equipped for color projection carries two shutters, the simple shutter for black-and-white pictures being left on when the additional color shutter for Kinemacolor pictures is added. A view of the operating side of the motion head is shown in Fig. 117 and a view of the color screen or color shutter is shown in Fig. 118. Intermittent Mechanism. The intermittent sprocket of the ordinary type of projecting machine is replaced by a device of the beater class, shown at 66 and 67 in Fig. 117. This beater cam pulls Fig. 116. A Kinemacolor Water Scene 267 192 THE MOTION PICTURE slack into the bottom loop of the film at every revolution, drawing the fihn down through the film gate just as the intermittent sprocket does in the usual t^-pe of American machine. In threading, the film is carried over the beater dog as it would be carried over the intermittent sprocket, except that there are no teeth to enmesh, and no presser roller for the beater dog. The course of the film through the motion head is seen very clearly in Fig. 117. The upper loop between the upper steady feed sprocket and the film gate should be rather small when the beater dog has just drawn the film down. Adjusiment of Color Screen. The color screen is made of thick sheets of gelatine clamped be- tween steel frames, as shown in I ^ -J [ (fOF ^ 6/ frame capable of being removed from the shutter shaft which car- ries it upon the projecting ma- chine, but the sheets of gelatine are capable of being removed from the frame. The red gelatine is used in a single tliickness, but the green gelatine is used in two parts, first a single thickness covering the whole of the green window, then another piece of green covering the middle portion and giving a thickness in the middle of the window. The object is to permit an adjustment of the relative volume of light in the red- light and green-light pictures, or in the red-light and green- light beams of fight throA\Ti upon the screen by the motion head through the color shutter when there is no film in the film window. Wlien the color shutter is adjusted properly, and the Kinemacolor motion head is turned rapidly with no film in the window, the picture screen should appear white. This is an adjustment that the Kinema- color operator must make. The Kinemacolor Motion Head 268 MOTION HEAD 193 The color of the red gelatine in the color shutter is a standard and, therefore, should not be changed. Were the color shutter put in the machine with only a single thickness of green gelatine, the screen would be greenish white when the motion head is turned rapidly without a picture film in the film gate, and all pictures when projected would take that greenish tint. On the other hand, were two thicknesses of the full size of green gelatine placed in the shutter, the screen would appear a light orange. The size of the smaller piece of green gelatine must be adjusted until the screen appears a clear white. This is the best adjustment attainable, and when done has adjusted the color shutter to the color Fig. 118. The Kinemacolor Color Shutter, Showing Red-Light Window, Green-Light Window, and Open Spaces for Blue Light of the arc lamp. The adjustment should be made with the arc of medium length, not just after feeding, nor just before feeding is needed. Nor should the color of the screen be judged just after looking at the arc, for the arc will have blinded the eye and will have rendered it impossible to judge the color of the screen. The color shutter is so adjusted upon the shaft which carries it that either red light or green hght will be admitted to the picture screen through the colored gelatine windows when the lens of the motion head is opened by the opaque shutter. The open shts of the color shutter will pass the lens while the opaque shutter has the lens closed. By inspection of the opaque shutter, it will be seen 939 194 THE MOTION PICTURE that the shutter is not black, but a dark blue, thus supplying to the picture screen a third tint through the open slots of the color shutter to correct some of the tints of the Kinemacolor picture when pro- jected. Framing. The Kinemacolor projecting machine has a larger range in framing than the ordinary machine, since it is necessary to frame to either one of a pair of pictures in the strip of film. Thus an image may be accurately centered in the film window when the film is at rest between shifts of the intermittent movement, and when the shutter therefore is open, but if the image be the red-light image and the shutter window just then before the lens be the green-light gelatine window, then the film must be framed forward or back one whole picture image to bring a green-light image into the film win- dow for the green gelatine of the color shutter. Framing Titles. To assist in the proper framing of the pictures for color before the actual pictures begin to be projected upon the screen, the titles are made in the green-fight images only, the red- light spaces being left of blank, black film between the green-light title images. The title, therefore, must be framed to green as well as framed to center in the film window and upon the picture screen. If the title comes red-light upon the screen, frame it up or down a full picture, making it green. The picture which follows then will come in its proper colors. Splicing. Owing to the hard usage of the film because of its projection at such a high rate of speed, the splices must be strong. The splices should be a half-picture or two full sprocket holes, in- stead of a quarter picture or only one sprocket hole, as is the case with ordinary film. By the beater type of shift mechanism, there is no intermittent or high-speed sprocket. All of the sprockets are steady feed and reasonably low speed, hence able to negotiate the less flexible splice better than the sprocket shift. Splicing for Alternation. This is splicing for color. The pic- tures in the unbroken film come red-light, green-light, red-fight, green-light, and so on, and this order must be preserved when cutting out a l)ad spot in the film and splicing up. Always cut an even num- \)CT of images. Cut out one and a half and lap a half, thus making a cut of two images, or four, or six, as may be necessary. If a single 270 MOTION HEAD 195 red-light image were cut out, it would leave two green-light images together. When that point would be reached in the projection of the film, the second of the green-light images would get the red-light window, the next or red-light image would get the green-light win- dow of the color shutter, and so on, every image getting the wrong color from the color shutter. Every object in the picture upon the screen showing any color at all would change its color. The trees would turn red instead of green, the sky orange instead of blue. The picture upon the screen would be spoiled until the projection operator could notice the condition and frame the film backward or forward one whole image. When it is found that a film changes thus in projection, a splice improperly made will be found at the point where the change occurs. This should be cut and respliced, taking out only one image, to change the film back to the proper alternation of red-light, green-light, and so on. The green-light spot opposite the green-light images, shown in Figs. 115 and 116, will aid in making the splices correct for color, and will aid in inspecting any splices which may be found in a film not yet projected. In some Kinemacolor films, the green-light spot is not printed photographically, but is made by a spot of green dye or pigment upon the gelatine of the film, or by a short green line upon the margin opposite the green-light picture. In the absence of either photographic spot or green mark, the alternation of pictures still may be observed in most Kinemacolor films by the comparative density of the images, or of some particular portion of the images. If there are green trees, they will be light and dark in alternate pictures, being lighter in the green pictures. The sky if blue will be lighter in the green pictures, but if gray or cloudy it will be'of about the same density in both. Perhaps a dress or house may give the light-dark-hght-dark alternation, and in sphcing it matters not which is light and which is dark, so long as the alter- nation of light-dark-light-dark for the series of pictures is continued properly over the splice. In Fig. 115, the bars of the flag give the light-dark alternation, being light in the red-light picture, while in Fig. 116 the sky gives the light-dark alternation, being light in the green-light picture. Film Inspection. A Kinemacolor film should be inspected 271 196 THE MOTION PICTURE thoroughly by the careful operator, who is jealous of his results and of his reputation, before projecting it for an audience. Every splice should be looked at, first, to see that it is not out of frame in the ordinary manner by a fraction of a picture, and, second, to see that it is not out of frame for color by the connection of two light images or two dark images, instead of having a light and a dark image meet at the splice. Also, note where the title joins the picture which follows it, and study it to determine whether the second image, or second image-length of film, after the last title image, is a green- lio-ht image as it should be. Also look carefully for any broken sprocket holes or weak places in the film which might break during the run, bearing in mind that the Kinemacolor film gets a harder bumping and jerking than any simple black-and-white film, and that a weak place is Hkely to break in the run. Any of these troubles found should be corrected. Then every projection of the film should be watched for indications of a weakening film. The film is being subjected to harder ser\ace, and a more rigorous care, if possible, is necessary than with black-and-white working at only 50 feet per minute. Oiling. The high-speed parts of the Kinemacolor projector should be oiled only with a good grade of sewing machine oil, and they should be oiled for every reel of film, that is, for continuous Kinemacolor projection, the rapidly moving parts of the motion head should be oiled every eight minutes. The high speed requires a thin oil, and a thin oil works out of the journals quickly and requires renewal. For the journals which have the less rapid motion, a medium heavy machine oil may be used, such as is used for ordinary pro- jection machines, oiling up at the beginning of the afternoon and again at the beginning of the evening run, or more frequently if the use of the machine is practically continuous. The upper reel or feed reel requires special attention, because as the film nears its end the speed of revolution of that reel becomes pretty high. The fixed spindle of the feed magazine, over which the feed reel slips, should be lubricated with vaseline, and care should be taken to see that the reel turns freely on the spindle when the magazine door is closed. Arc Lamp. With one window of the color shutter taking out all the green light and passing only the red light for the red-light 272 MOTION HEAD 197 images, and with the other window of the color shutter taking out all the red hght and passing only the green light for the green-hght images, it will be seen that a total of only half the light of the arc which passes through the film and the lens ev^er reaches the picture screen, the other half (sometimes the green half, sometimes the red half) never getting any farther than the color shutter. To give an equal brightness upon the picture screen, compared with black-and-white pictures, the Kinemacolor film and color shutter require a much brighter arc. The resistance of the rheostat may be reduced, or two rheostats may be connected in multiple to give the additional current, together with carbons of a slightly larger diameter, say |-inch. Lamp currents of 60, 75, and even 100 amperes have been sug- gested. The maximum current used must always be a compromise between screen brilliancy and condenser breakage. Direction of Film Wind. The feed reel requires the film to be wound with the emulsion side "inside" when the reel is full, that is, the film is started with the emulsion side next the core when rewind- ing. The take-up reel turns "counterclockwise" and winds the film up with the emulsion side "outside," the film being started upon the take-up with the celluloid side next the core. \\Tiile the feed reel might run in either direction, it is designed to nm clockwise when feeding. FRIESE=QREEN PROCESS It may be said of the Friese-Green process of motion pictures in natural colors by colorphotography direct from nature that it is being developed in England. How nearly ready for the market the Friese-Green process is, cannot be said. Several very successful pubhc exhibitions of the color projection achieved by the process have been given. The Friese-Green process resembles the Urban-Smith process in that it produces the innumerable variations of color in nature by recording them in a few primary colors and then recombining them upon the picture screen by persistence of vision. The Friese-Green system of projection uses two projecting lenses, projecting two images of two colors upon the picture screen at the same time, shifting each one fourteen times per second, that is, at the regular speed of shift- 273 198 THE MOTION PICTURE ino- ordinary black-and-white picture film. The negative is made through a color shutter of three colors. The colors really are orange, green, and violet, but are called red, green, and blue. Process of Manufacture^ The process of making is by the use of a double camera, as shown in Fig. 119, the camera being composed of two motographic mechanisms built into a single case, each mechan- Fig. 119. The Friese-Green Color-Motography Camera in Operation ism using its own roll of sensitive film and its own' intermittent shift mechanism, and having its own lens and its owti color shutter. They are linked by being driven by the same crank shaft, and further by having one opaque shutter common to the two lenses. One of the lenses closes while the other opens, alternating until the picture is completed upon both reels of negative film, the alternate pictures being upon the two reels, respectively, when finished. In Fig. 119, the right hand of the operator turns the crank which drives the film mechanism, while the left hand is upon the panoram handle of the tripod head. 274 MOTION HEAD 199 In addition to alternation in taking the negative images of the subject photographed, the two lenses take the image in a different color of light at each exposure. The color shutter, or color filter, changes for each exposure in each camera in the order of blue, green, red, blue, green, red, and so on, and as the two series of pictures are taken in alternation they are taken as follows: (1) A green-light image with the left camera; (2) a blue-light image with the right camera; (5) a red-light image with the left camera; (4) a green-light image with the right camera; (S) a blue- light image with the left camera; (6) a red-Hght image with the right camera; (7) a green-light image with the left camera; and so on. Projection of Film. In projecting, a similar color shutter of three colors is employed. A double motion head is used, with two arc lamps, two intermittent mechanisms, and two lenses, also two color shutters. The intermittent mechanisms and shutters are driven by the same crank handle, as are also the two color shutters. A combination of simultaneous and alternative color projection is achieved by the two lenses and mechanisms of the Friese-Green projection head, as follows: (1) The left lens projects a green-light image, and while the green light of the left lens is still upon the picture screen (3) the right lens projects a blue-light image upon it, thus giving the two colored images green and blue upon the picture screen at the same time; but the left lens now cuts off the green-light image and shifts its film and its color shutter, and (5) projects a red-light image upon the picture screen while the blue-light image of the right lens is still upon it, thus giving two images, blue and red, upon the picture screen at the same time; now the right lens cuts off the blue-light image and shifts its film and color shutter, and (4) projects a green- light image upon the screen while the red-light image of the left lens still continues, thus giving two images, red and green, upon the pic- ture screen at the same time; again, while the green-light image from the right lens continues, the left lens shifts and (5) projects a blue- light image, thus giving two images, green and blue, upon the picture screen at the same time. This cycle of colors is repeated indefinitely or until the end of the scene. As the images are shifted for color, each image shows a progressive position of all of the objects in motion in the subject, so that motion as well as color is depicted. 275 200 THE MOTION PICTURE The Friese-Green picture films when on reels of course come in pairs, and a pair of reels of 1,000 feet each will run upon the screen twenty minutes, each film running 50 feet per minute. Splices. Splices, if made at all, require great skill and care. A break may be repaired sometimes by a patch without cutting out any of the film, but if any cut is to be made, it is necessary to cut three images from each of the two films, and in the same place, that unison between the two films of the pair may be maintained, and that synchronism between the images and the color shutters may be maintained. Color Shutter. The color shutter of the Friese-Green camera and projecting machine is not the disk of the Urban-Smith device, but a transparent film band, endless, colored in sections with the three colors, and traveling with the film through the film gate of camera or projecting machine, respectively. Care in threading up is necessary, with reference to the film pair, to get correspondence, and with reference to framing for color of the two color shutters or color bands. Development of S}'Stem. To show as far as possible the progress which has been made in the development of the Friese-Green system, and the time which has been consumed in the experiments, the fol- lowing is quoted from an English magazine. The Kinemaiograph Weekly, of November 24, 1910: At Pendleton's Pictures, Co-operative Hall, Crewe, on Thursday last, Mr. Friese-Green gave a display of his system of natural color animated photography. The pictures were shown during the ordinary program, an announce- ment being made from the platform that a picture in color of Mr. Friese- Green 's son signaling with colored flags, taken six years ago, and one as recently as two months ago, would be sho^VTi. These films, it was explained, were taken in the laborator}^ and the commercial results of Mr. Friese- Green's labors would be submitted in about a month's time. In the six-year-old picture, three colors apparently were employed and the machine ran at ordinary speed. The results were crude, the picture was unsteady and fuzzy, and occasionally such colors as there were would dis- appear altogether. The two-year-old results were very much better. The subject was a revolving vase of flowers, but it was revolved so slowly as to be almost a still picture. There was a lack of true color in the blooms, but now and then a fine stereoscopic effect appeared. The last, and two-months-old picture was again an improvement, and 276 MOTION HEAD 201 represented a colored-ware dessert dish containing fruits. The results obtained were curiously varied. Intermittently the color rendering would appear to be very good indeed, and the stereoscopic effects produced by the dish revolv- ing would be very pronounced, giving a beautiful, soft, and natural appear- ance. The unsteadiness, however, was very great, and the defects, it must be confessed, were largely apparent. It remains to be seen what Mr. Friese-Green can accomplish when he comes to do outdoor work; the films described above were the results, of course, of long exposures and slow rates of speed. Whether his methods infringe any of the master patents is a matter upon which we do not feel called upon to express an opinion. That question may be left with those directly interested. It is apparent from the above account of the results obtained that progress has been made, and we wish Mr. Friese-Green success in his continued efforts. FILM MANUFACTURERS The object of this Hst is to give to the reader some Httle knowl- edge of any manufacturer whose name or trademark he may see upon a film. The list does not pretend to be complete, not even for the manufacturers in the United States. In many instances, no in- formation other than the home office address, or the American im- porter's name and address, is given. Possibly some of the manufac- turers mentioned have discontinued the production of films, but so long as their films still are used in picture theaters, such data as is given concerning them will have an interest for that reason. Adolpho Croce, Milan, Italy. Ajax Film Company, A. J. Clapham, Managing Director, 12 East 15th Street, New York, N. Y. "Ambrosio." Societa Anonima Ambrosio, Torino, Italy. Films im- ported into United States by New York Motion Picture Company, 1 Union Square, New York, N. Y., and sold through the Motion Picture Distributing & Sales Co. Ambrosio Film Manufacturing Company, 16 Rue St. Marc, Paris, France. Films imported into United States by New York Motion Picture Company, 1 Union Square, New York, N. Y. American Cinephone Company, 124 East 25th Street, New York, N. Y. Controlling patents for the Cinephone, a talking picture device, for the United States. Markets its product only through the American Kinograph Company. American Film Manufacturing Company, A. M. Kennedy, General Manager, Bank Floor, Ashland Block, Chicago, 111. Making picture film under the sign of the "Flying A." Sales through the M. P. Distributing & Sales Co. American Kinograph Company, 124 East 25th Street, New York, N. Y., J. A. Toupin, Manager. Operating under the Cinephone patents. Supplies Cinephone sound records and picture film for the Cinephone Talking Pictures, also Cinephone talking machines for the Cinephone sound records. 277 202 THE MOTION PICTURE American Motor Racing Picture Company, 330 East 3oth Street, Chicago, Illinois. Irregular releases of special film pictures. American Mutoscope and Biograph Company, New York, N. Y. Commonly called the "Biograph Company." Trademark, an "AB" mono- gram in a circle Offices and studio in New York. Office address, 11 East 14th Street, New York, N. Y. Studio also in southern California Licensed imder patents controlled by the Motion Picture Patents Company of America Film leased to licensed film exchanges only. Animated Motion Picture Patents Company, New York, N. Y. A patent-holding company controlling a patent issued to Meredith Jones for a camera making a motion picture without stopping the film behind the lens. Animatophone Syndicate, Ltd., 11 Denman Street, Piccadilly Circus, London, W., England. Talking and Singing Pictures. Aquila Film Manufacturing Co., Torino, Italy. Atlas Film Company, 10 East 15th Street, New York, N. Y. Films sold through the Distributing and Sales Company. Manufacturing picture films imder the trademark of Atlas supporting the globe of the earth with a picture film encircling both athlete and globe. Barker Motion Photography, Ltd., Topical House, 1 Soho Square, London, W. Sign of the Bulldog. Bat Films. Lyons, France, 8 Rue du President Carnot. Bavaria Film Manufacturing Company, Strassbourg. "Biogr.\ph" Film, the American Mutoscope & Biograph Co. "Bison" trademark, New York Motion Picture Manufacturing Co. W. Butcher & Sons, Ltd., Camera House, Farringdon Avenue, London E. C, England. Making picture films under the trademark, "Empire." Capitol Film Co., Washington, D. C, Sig. G. Bernstein, General Man- ager. Making picture films under the name of "Capitol Films," with the sign of the capitol dome in the letter "C." Carlton Motion Picture Laboratories, 1 Union Square, New York, N. Y. Films sold only through the M. P. Distributing & Sales Co. Making picture films under the trademark "Reliance." Champion Film Company, Mark M. Dintenfass, General Manager, 12 East 15th Street, New York, N. Y. Making picture film under the trademark "Champ" and the sign of the victorious gladiator. Sells through the ^I. P. Distributing & Sales Co. "Chicken Film," Pathe Freres, sometimes so called because of the trademark, the sign of the red rooster. E. G. Clement, 30 Rue du Petites-Ecuries, Paris, France. Columbia Film Company, 301 West 27th Street, New York, N. Y. Sells only through the M. P. Distributing & Sales Co. Continental Film Manufacturing Company, Copenhagen. Cosmopolitan Film Company, Ltd., London, England. Cricks & Martin, London, England. Makers of film pictures under the "Lion's Head" trademark. Defender Films, Wm. H. Swanson, General Manager, 111 East 14th Street, New York. Sold only through the M. P. Distributing & Sales Co. Ste. Drankoff, 12 Nicolaeiwich, Saint Petersburg, Russia. Eclair Films, Paris, France, 8 Rue St. Augustin. fl 278 MOTIOxN HEAD 203 Edison Manufacturing Company, 65 Lakeside Avenue, Orange, New Jersey. Making picture films with the trademark of the "Circle E." Licensed by the Motion Picture Patents Company of America, which controls the Edison patents. Films are leased to licensed film exchanges only. Essanay Film M.\nufacturing Company, 435 North Clark Street, Chicago, 111. Studios in Chicago and Colorado. Licensed under the patents controlled by the Motion Picture Patents Company of America. Leases film to licensed fUm exchanges only. Trademark, the Indian head. Film d'Art Film Manufacturing Company, Paris, France. The Gaumont Company, Paris, France. Office, 57 Rue St. Roch. Usines et Theater, 12 Rue de Alouettes, Paris. American office, 125 East 23rd Street, New York. Films imported into United States by George Kleine, Chicago, 111. Gnome Motion Picture Company, offices and studios at southwest corner of Park and Tremont Avenues, Bronx, New York, N. Y. Licensed under patents of the Animated Picture Patents Company. Great Northern Film Company. Home office, "Nordisk Film Company, Copenhagen." American office, 7 East 14th Street, New York, N.Y. Trade- mark of the Polar Bear on the Earth Globe. Hepworth Manufacturing Company, London, England, making picture films under the trademarks of "Hepworth" and "Hepwix." HisPANO Films, Barcelona, Spain, Craywinckel, 20 San Gervasio. David Horsley, German Savings Bank Building, 4th Avenue and 14th Street, New York, N.Y. Making picture films under the trademark of "Nestor." Sold through the M. P. Distributing & Sales Co. "Imp" trademark, Independent Motion Picture Co. Independent Moving Picture Company op America, 102 West 101st Street, New York, N. Y. Carl Laemmle, President. Manufacturing picture films under the trade name "IMP" and the trademark of an imp associated with a shield design bearing the letters "IMP." Films sold through the Motion Picture Distributing and Sales Company. Itala Film Manufacturing Company, Torino, Italy. Films imported into United States by New York Motion Picture Company, 1 Union Square, New York, N. Y. Kalem Film Manufacturing Co., New York, N. Y. Making picture films under the name "Kalem" and the sign of the blazing sun with the word "Kalem." Licensed by the Motion Picture Patents Company of America. Films leased to licensed film exchanges only. KiNEMACOLOR COMPANY OF America, Allcntown, Pa. Making Kinema- color picture films and manufacturing Kinemacolor projecting machine. Kinemacolor is a process of motion pictures in natural colors by color pho- tography direct from nature. "KiNETo" Films. Kineto, Ltd., 48 Rupert Street, Shaftsbury Avenue, London, W., England. George Kleine, 52 State Street, Chicago, 111. Imports "Gaumont" and "Urban-Eclipse" films into America under license of the Motion Picture Patents Company of America. Films are leased to licensed exchanges only. "Latium" Film, Manifattura Cinematografica Italiana. "Le Lion" Cinematographes Company, 15 Rue Grange-Bateliere, 279 204 THE MOTION PICTURE Paris, France. Manufacturing films under the trademark of the lion ram- pant mauling a roll of film. "Lion's Head" Film, Cricks & Martin, London, England. LuBiN Manufacturing Company, Philadelphia, Pa. Making picture film under the trademark of the Liberty Bell. Licensed under the patents controlled by the Motion Picture Patents Company of America. Leases film to licensed film exchanges only. Lux Film Manufacturing Company, Rue Louis-le-Grand, Paris, France. Manif.\ttur.4. Cinematografica It.\lia, 77 Via Appia Nouva, Rome, Italy. Making picture films under the trademark, "Latium Film." G. Melies, New York, N. Y. Making picture films under the trade- mark of the "Star." Licensed by the Motion Picture Patents Company of America. Films leased to licensed film exchanges only. Motion Picture Distributing and Sales Company, 111 East 14th Street, New York, N. Y. Act as selling agents for a number of American and Foreign manufacturers. Handle Eclair, Imp, Yankee, Bison, Powers, Thanhouser, Ambrosio, Atlas, Champion, Nestor, Itala, Defender, Lux, Cines, Solax, Great Northern, Columbia, Capitol and Reliance films for the United States. Motion Picture Patents Company of America, 10 Fifth Avenue, New York, N. Y. A company organized to control the Edison, Biograph, Armat, and Vitagraph patents pertaining to the motion picture industry. Some of these patents are the following: Reissue 12,192; 578,185; 580,749; 586,953; 588,916; 673,329; 673,992; 707,934; 722,382; 744,251; 770,937; 771,280; 785,205 and 785,237. The following companies are licensed by the M. P. Patents Company to manufacture picture film vmder the above listed patents: The American Mutoscope and Biograph Company of New York City; the Edison Manufacturing Company of Orange, New Jersey; the Essanay Com- pany of Chicago; the Kaleni Company of New York City; Lubin Manufacturing Company of Philadelphia; Pathe Frhres of Bound Brook, New Jersey; the Selig Polyscope Company of Chicago; the Vitagraph Company of America of New York City; and G. Melies of New York City. In addition, Pathe Fr^res are licensed to import from their factories in France, and George Kleine of Chicago is licensed to import "Gaumont" and "Urban-Eclipse" films. This makes a total of ten licensees of the Motion Picture Patents Company. The output of each of the licensees is limited by the terms of its license. All films manu- factured or imported under the licenses of the IMotion Picture Patents Company are not sold, but remain the property of the manufacturer or importer, being leased to licensed film exchanges only for a term of months, during which time the licensed film exchange rents the films to exhibitors, and at the end of which time the exchange returns the film to the manufacturer or importer to be destroyed. By this means, only the latest films may be obtained from the licensed film exchanges. The object is to cause the withdrawal from theater exhibition of films which have had a reasonable amount of wear, and to main- tain as high a standard as possible in the film theaters both for lateness of titles and freedom from wear of the films. National Film Manufacturing & Leasing Co., 12 East Fifteenth Street, New York City. A manufacturing and leasing company operating 280 MOTION HEAD 205 independently of the Motion Picture Patents Company of America, and independently of the Motion Picture Distributing and Sales Company. Navone Film, Torino, Italy. "Nestor" Films, made by David Horsley, German Savings Bank Build- ing, 4th Avenue and 14th Street, New York, N. Y. New York Motion Picture Company. Offices and Studio in New York City. Office address, Lincoln Building, 1 Union Square, New York, N. Y. Making picture film under the trademark of "Bison" and the sign of a buffalo rampant. Sells film only through the M. P. Distributing & Sales Co. Importing agents for the United States for "Ambrosio" and "Itala" films. Paragon Bioscope Company, Ltd., 13 Cecil Court, Charing Cross Road, London, W. C. Pathe Freres. Trademark of the Red Rooster. Home office, 14 Rue Favart, Paris, France. American offices in New York, Chicago and San Francisco. Two studios in France and an American studio and factory at Bound Brook, New Jersey. Produce American and foreign subjects, import- ing many foreign subjects into America. Leaders in so-called "hand colored" pictures, colored by stains in an imitation of the colors of nature, the colors being applied to the film by machinery. American factory and American importations of foreign films licensed under patents controlled by the Motion Picture Patents Company of America. Films leased to licensed film exchanges only. The Powers Company, 241st Street and Richardson Avenue, New York, N. Y. Making picture films under the trademark of "Powers Picture Plays." Sales through the M. P. Distributing & Sales Co. This company takes its name from "Pat Powers," and should not be confused with the Nicholas Power Company, which makes the Cameragraph projecting machines and does not make film. "Reliance" trademark, Carlton Motion Picture Laboratories. Revier Motion Picture Company, H. Revier, President, Majestic Theater Building, Salt Lake City, Utah. The trademark is a picture of a temple with the word "Revier." Selig Polyscope Company, Chicago, Illinois. Offices at Dearborn and Randolph Streets. Studio and factory at North Western Avenue and Irving Park Boulevard. Making picture film under the sign of the "Diamond S." Licensed by the Motion Picture Patents Company of America. Leases film to licensed film exchanges only. Sicania Film Factory, 45 Piazzi Giuseppe Verdi, Palermo, Italy. The trademark "Sicania." SociETE CiNES. Making films with the trademark of the Wolf-and-Babes. Office address, 11 Rue Saint Augustin, Paris, France. Studios in France and in Italy. SoLAX Company, 147 Fourth Avenue, New York, N. Y., factory and studio at Flushing, Long Island. Making picture film under the name "Solax." Sold only through the M. P. Distributing & Sales Co. Sunny South Film Company, Rhodes Building, Atlanta, Ga. Thanhouser Company, manufacturing with the trademark "TCO." Offices and studio at New Rochelle, N.Y. Films sold through the Distribut- ing and Sales Company. 281 206 THE MOTION PICTURE Tyler Film Company, Ltd., London, England, makers of film pictures under the trademark, "T. F. C." Unitas Film Manufacturing Company, Torino, Italy. . Charles Urban Trading Company, film publishers, Urbanora House, 89 Wardour Street, London, W., England. "Urban" and "Urban-Eclipse" black-and-white films and "Urban-Smith" Kinemacolor films. The Vitagraph Company of America, 116 Nassau Street, New York, N. Y. Studio on Long Island. Licensed under the patents controlled by the Motion Picture Patents Company of America. Film leased to licensed film exchanges only. Trademark, the letter "V" surmounted by an eagle with spreading wings. "Warwick Trading Company, Ltd., 113 Charing Cross Road, London, W. C, England. "Wrench" Films, 50 Gray's Inn Road, London, W. C, England. Yankee Film Company, 344 East 32nd Street, New York, N. Y. Making picture film under the trade name of "Uncle Sam Films" and the sign of Uncle Sam in costume holding a white "Y." Films sold through the M. P. Distribut- ing & Sales Co. 282 li c ■^ 3 a'^ O -^ a §^^ ■< J fe W a-s t3 S >• " "-"4- W 2 ° £ i" PHOTOGRAPHY THEORY The making of photographs may be divided into three very general or theoretical steps: First, producing an image of the scene or object of which it is desired to make a photograph. Second, receding the image in permanent form. Third, copying, multiply- ing, or reproducing the image into as many finished photographs as may be desired. Any of these steps may be accomplished in any of several ways by the photographer, according to the results which he desires to attain, or according to the limitations of the apparatus which he has available. Thus, images usually are formed for photography by means of a lens; but if the photographer has no lens, or arbitrarily decides not to use it, he may form an image without it. The image formed being composed of rays of light of different strengths, the second step taken by placing in the image a surface bearing a substance which is sensitive to light and which will be discolored to different degrees by the different strengths of the different rays and by the spots of light formed by them in the image. Tliis second step produces the record of the image, and from it a number of finished photographs may be produced in a manner not altogether unlike the production of several thousand newspapers by a printing press after the typesetters have made ready the printing tj'pes and the engravers have made ready the printing picture plates. MECHANICAL DETAILS Camera. The camera is a dark box within which the photog- rapher forms the image. The light is admitted to the camera dur- ing the making of the photograph, and in most cameras during the preparation for the photograph and the proper adjustment of the camera for forming the desired image. Pin=hole Image. To understand just how the image is formed in the camera, perform the following experiment: Copyright, 1911, by American School of Correspondence. 11 2 THE MOTION PICTURE Take a paper box, white inside, about the size of a shoe box. Remove half of the Hd. In the middle of one end of the box, punch a hole with a darning needle, making a hole about -e inch in diameter, with smooth edges. Place the box in the window, the hole toward the street, and with the half-lid on that part of the top of the box near the street. Draw the shade to the top of the box, and obscure the remainder of the window as well as other windows of the room so that the only light received will be through the small hole in the end of the box — the pin-hole as it is termed in photography, Fig. 1. On the inside of the box, at the end opposite the pin-hole, there will BOX I /MA6E ^ Fig. 1. Pin-hole Image be formed an image of the objects upon the opposite side of the street. The image may be viewed through the open half of the top of the box, and will be seen a living image, in natural colors, but inverted, its size depending upon the length of the box. Try it with boxes of different lengths, or moving a white card in the box. Inverted Image. The reason why the image is inverted is shown in Fig. 2, in which the object, the pin-hole, and the image are rep- resented. All rays of light pass in straight lines, and all the light from the top of the tree at the right which gets through the pin-hole passes in a straight line to the bottom of the image at the left; light from the bottom of the tree goes to the top of the image. This is true for every point of the view; hence, the view is inverted in the image. 12 PHOTOGRAPHY 3 Now with a lead pencil, enlarge the pin-hole until the pencil can pass through. Note the difference in the image. It is blurred. Each point in the scene makes a spot in the image as large as the hole in the box; yet the image as a whole is brighter. A spectacle lens placed over the hole in the box might make the image sharp, but at tliis point the pin-hole experiment may be abandoned and the working of the photographer's camera as it is commercially used may be taken up to complete the study of the first step in theory, or the formation of the image in practice. Buying a Camera. The learner who intends either to make moving pictures after learning still photography, or to make good still photographs, must first purchase a tripod camera. Concern- ing the work of hand cameras, a photographer handling amateur work at a holiday resort is quoted as saying that of more than a Fig. 2. Inverted Image thousand negatives developed by him in one summer there were not twenty good pictures and hardly forty good negatives. Only with the tripod camera can the photographer know what he is doing and then operate his camera intelligently and successfully. The camera purchased for intelligent work must be either 4-inch by 5-inch size, with bellows draw of 12 inches or more, or 5-inch by 7-inch size, with bellows draw of 15 inches or more. Smaller than 4 by 5 is too small for intelligent work by the ambitious amateur, and larger than 5 by 7 is too heavy for amateur work. In either case, the camera should have a single swing, and must have a rising front and holders for glass plates; it may have a convertible rectilinear lens or a more expensive convertible anastigmatic lens, but in either case the lens must be convertible and should be equipped with an iris diaphragm and an automatic shutter. The usefulness of each of these features will appear as the operation of the camera is de- 13 4 THE MOTION PICTURE scribed. A camera 4 by 5 may be had at a catalogue price of S25.00 or more, and a camera 5 by 7 at $33.00 or more, filling all require- ments. Two extra plate-bolders should be bought, that six plates may be carried into the field. A tripod and focusing cloth complete the necessary field equipment, with the possible addition of an exposure meter. Construction of Camera. The body of the camera consists of the back frame, the front frame, and a base. The base connects the back and front frames and upon it the front frame moves as upon a track. Connecting the back and the front is the bellows. The front carries the lens, mounted upon a detachable lens board; the back carries the ground glass or focusing screen, and permits the insertion of one of the plate-holders in such a manner that when the plate-holder is inserted the ground glass is pushed out of its normal position and the glass plate within the holder occupies the position formerly held by the ground glass. Place the camera in the window as the shoe box was, and open shutter and diaphragm. The shutter is opened by setting its index to "T," or "Time," and operating it with the rubber bulb. The diaphragm is opened by setting its index to the lowest number, probably 8. Extend the bellows until a sharp image is seen upon the ground glass. Look at the ground glass, not through it. If the back of the camera and the operator's head are covered with the focusing cloth, it will not be necessary to darken the room for this experiment. By moving the camera front to different positions, it will be observed that the image is sharp in only one position. This is the position of focus of the lens. Lenses. The lens is composed of a barrel carrying the shutter and iris diaphragm in its middle portion and carrying at each end a "lens cell," or metal mount, into which the glasses of the lens are fixed. The glasses may be removed from the lens barrel by un- screwing their mounts from the barrel. Unscrew the front lens ceP and extend the bellows until the image upon the ground glass is sharp again. This is the focus for the "back combination," or that cell which still remains in the lens. The bellows is longer, the image is larger. Sometimes the front combination of the lens is of still longer focus than the back combination, giving an image still larger, but with still longer extension of the bellows. 14 PHOTOGRAPHY 5 Replace the lens cells. Select in the image a distant object, such as a chimney 500 feet away. Focus sharply upon it by moving Fig. 3. Pin-hole without Lens the camera front until the cnimney is sharp. Note a near object, a house or tree within 50 feet; it is not sharp. To focus sharply upon the near object, it is necessary to extend the bellows slightly. Now the distant object is not sharp. Try to place the focus between the two; then reduce the iris diaphragm to 32 or even 64. Now both distant and near objects are sharp. Remove both lens cells. Shut the iris diaphragm as close as it will move. Look upon the ground glass; the image of the shoe box is there. Move the bellows to different lengths; the size of the Pin-hole with Lens pin-hole image is changed but it is in as good focus in one place as another. The pin-hole image has no definite length, and everything, near and far, is in focus. Replace the lens cells. With the diaphragm 15 6 THE MOTION PICTURE still at its smallest size, the lens makes the image sharper, but a position may be found at which everything seems to be in focus, both near and far objects. This is called the condition of universal focus. Focal Length. The distance from the ground glass to the center of the lens when the image is in focus upon the glass, is called the focal length of the lens, and usually is expressed in inches. The focal length of the two combinations or cells of the lens when used together is shorter than the focal length of either of them. With a 5 by 7 lens, the complete lens should have a focal length of 7 inches or a little more; each of the combinations alone should be about 12 inches, or one of them about 11 and the other about 14 inches. Fig. 5. Lens Image Figs. 3 and 4 show the action of the lens. The glass of the lens bends the rays of light, which proceed from a point in the sub- ject until they reach the lens and then are bent by the lens to approach until again they meet in a point, making a sharjjer spot of light on the ground glass in Fig. 4 with the lens than in Fig. 3 where the pin-hole without the lens is shown. This is true of all points of the subject, as shown in Fig. 5. The distance from the lens to the place where the ray again comes to a point depends upon the strength of the lens in bending the rays, and this distance is the focal length of the lens. In Fig. 6 the back lens cell alone bends the light to bring it to a focus; while in Fig. 7 both front and back lens cells bend the light, one after the 16 PHOTOGRAPHY 7 other, bending it to a much greater extent, bringing it to a focus in a shorter distance, giving a shorter focus or shorter lens length, and producing of course a smaller image on the ground glass. Fig. 6. Long-Focus Lens Measuring Length. Without a camera, a lens may be measured approximately by focusing the image of the sun upon any convenient surface, such as a small card, then measuring with a iiiler the distance from the middle of the lens barrel to the card. With a camera, focus upon a very distant object, and measure from the middle of the lens barrel to the ground glass. A more accurate method, where a camera of sufficiently long bellows is available, is to focus upon any close object until the image on the ground glass is exactly the size of the object. Measure the distance between the object and the ground glass and divide by four. To make this measurement con- veniently, cut two slips of paper of equal length and attach one to the ground glass and the other to the glass of the window. Place the camera on a table where it may slide toward the window to change the size of the image. Use the largest diaphragm opening. When the edges of the image of the slip of paper are sharp and when the image on the ground glass and the slip of paper on the ground glass are of the same length, the distance between the object and the image will be four times the focal length of the lens. Fig. 7. Short-Focus Lens Position of- Diaphragm Opening. The influence upon the image of the diaphragm opening, or "stop," and of its position with reference to the lens is shown in Figs, 8, 9, and 10. In each of these figures, there are shown a photographic subject composed of straight 17 8 THE MOTION PICTURE lines, a lens, a stop opening, and an image of the subject formed by the lens through the diaphragm. In each figure, the subject and the image are shown in a front view, while the lens and diaphragm Fig. 8. Barrel Distortion are shown in side view, or rather in sectional view as though cut through the middle. In Fig. 8, the diaphragm opening is in front of die lens, between the lens and the subject to be photographed. The result is a bend- ing of all the straight lines of the image, drawing the ends of the lines toward the middle line of the image, both horizontally anrl vertically. This form of distortion is called barrel distortion. In Fig. 9, the diaphragm opening is behind the lens, between the lens and the image. This results in bending the lines of the image in the opposite direction, and produces what is called a pin-cushion dis- tortion. In Fig. 10, a double lens is shown, the glasses of the lens l)eing divided into two cells with the diaphragm or stop between them. With such an arrangement the pin-cushion distortion of the front lens cell is just balanced by the barrel distortion of the back lens cell, and the resulting image has all its lines straight. Such a lens is called a rectilinear lens. To avoid distortion, the diaphragm Fig. 9. I'in-cushion Distortion must be placed between the two cells at the proper distance from both. Of the two forms of distortion shown in Figs. 8 and 9, the barrel distortion is the less objectionable, and when a single lens is used, it should be placed in the back end of the lens tube, even 18 PHOTOGRAPHY 9 though it be the front cell of the complete lens. The single lens senses satisfactorily for landscape and portrait work, in either of which it may be said there are no straight lines In photographing 10. Rectilinear Lens architectural subjects, where the straight lines of the sides of build- ings are near the edge of the plate, and in interiors, only the rec- tilinear lens may be used if passable results are desired. Focusing. Bringing the desired image into focus is controlled by the position of the ground glass at the proper distance from the lens, and also by the size of the opening in the diaphragm or stop. Every point in the image is formed by a mass of light rays which is conical in form, as big as the stop opening at the lens, and tapering down to a point at or near the groimd glaas. \Mien the exact tip of this cone is upon the surface of the ground glass, the point is in focus and sharp in the image. \Mien the tip of the cone is a little behind or in front of the ground glass, the point is slightly blurred, but if not too much blurred it may be said to be still in focus. The amount of blur depends upon the size of the cone at the place where the ground glass is met. Fig. 11 shows a lens with Fig. 11. Lens without Diaphragm Stop a large stop opening. The point B of the subject is in focus at the point h of the image; the point A of the subject is in focus at the point a of the image. With the ground glass at the vertical line, through a the point A will be shaip and the point B will be blurred in the image. With the ground glass at the vertical line, through h the point B will be .sharp in the image and the point A will be blurred. 19 10 THE MOTION PICTURE Fig. 12 shows the same system with a smaller stop opening. The cone from the point A is smaller where it crosses the vertical line through b, hence the blur will be less, and the focus more nearly Fig. 12. Lens with Diaphragm Stop correct. With the ground glass midway between the points a and b, both will be slightly blurred, but the blur will be less with the smaller top opening, Fig 12 "Depth of field" in an image refers to the •listance from the nearest object in focus to the farthest object in focus. With the smaller stop opening, the depth of field is increased. Spherical Aberration. Lenses ground by machines present spherical surfaces upon both sides, although not of concentric spheres. Such a lens bends a ray of hght to a greater degree when the ray passes through the lens near the edge than when the ray passes through the lens near the center. This is illustrated in Fig. 13. By the greater bending, the rays from the object C which pass near the edge of the lens are brought to focus on the line c, while those through the central portion are brought to focus upon the line c'. This defect in the lens is reduced by the use of a lens which is meniscus in form, having one convex and one concave surface, as illustrated in Fig. 14. It is reduced also by the use of a smaller stop opening, as illustrated in Fig. 15. Fig. 13. Spherical Aberration in Convex Lens Chromatic Aberration. The light rays of different colors are affected to different degrees by the refractive attribute of the glass of the lens. The violet light is bent through a greater angle than the yellow light, and the remaining colors, as well as the ultra-violet rays, are changed in direction through different angles. This pro- 20 PHOTOGRAPHY 11 duces the effect of bringing the different colors to focus at different distances from the photographic lens of the simplest type, viz, of a single meniscus piece of glass. The principle involved is the same Fig. 14. Spherical Aberration in Meniscus Lens as that by which a single ray of white light is separated by a prism into its elementary colors, a band of colored rays being secured by the separation of the single white ray. The effect in a photographic lens is shown in Fig. IG. The ray of white light from the point D of the subject is brought to focus in several different points according to the colors into which the light is separated. The yellow light is brought to focus at the line d, while the violet light is brought to focus on the line d'. Of all the colors composing white light, yellow affects the eye to the greatest degree and, consequently, in focusing the camera by looking at the image upon the ground glass, the yellow light is appreciated by the eye and the ground glass is brought to that position in which the yellow rays are in focus. At the same time, the red and blue rays are so nearly in focus that they unite to give the appear- ance of white light in focus upon the screen. When the sensitive plate is placed in the camera, occupying the position of the ground glass, and the light is permitted to fall upon it through the lens, Fig. 15. Spherical Aberration Reduced by Diaphragm Stop the conditions of appreciation of the light are changed. The sensitive plate is most sensitive to the blue — the violet antl the ultra-violet rays — and these are not in focus upon its surface. Outside of the lens, the remedies for color aberration are to focus through a blue glass, to use a blue ground glass, or to wear ai 12 THE MOTION PICTURE blue spectacles. Another method is to know the specific correction for the lens used and to move the ground glass the proper distance toward the lens after focusing upon the yellow image. Fig. 16. Chromatic Aberration Within the lens, the correction may be made by uniting two pieces of glass of different refractive powers, one lens being ground "positive," or thicker in the middle than in the edges, and th* other one being ground "negati\'e," or thinner in the middle than in the edges. Two of the surfaces have the same curvature and the two lenses when completed are cemented together, Fig. 17. Even the cheapest classes of lenses are thus made double, except in the smallest sizes and when of short focus. A rectilinear lens, composed of two single lenses, each of which is corrected for chromatic aberra- tion, would present a combination of glasses such as is shown in section in Fig. 18 or Fig. 19. Astigmatism. The meaning of this word is icith no 'point. Its meaning as applied to a photographic lens is that the lens has not the ability to bring to a focus at a point all of the rays proceeding from a point in the subject. Thus a point in the subject becomes something else in the image. The bundle of rays passing from a point in the subject and through the stop opening takes the form Fig. 17. AcliTomatic Lens shown in Fig. 20. The best focus is obtained by placing the ground glass at the line 6, where the point takes the form of a cross. When tiie ground glass is at the line a nearer the lens, the point takes the form of a short radial line, or ellipse, with its longer axis radial from 22 PHOTOGRAPHY 13 the center of the image; when the ground glass is at the hne c farther from the lens, the point takes the form of a short arc about the center Fis Fig. 19. Achromatic Rectilinear Lenses of the image, or of an approximate ellipse of which the shorter axis is radial and the longer axis is an arc instead of a straight line. The remedy for astigmatism lies in the construction of the lens, and lenses which are corrected for astigmatism are called Fig. 20. Bundle of Raj's with Astigmatism anastigmals. Two, three, four, and even five pieces of glass are used sometimes in producing single lenses free from astigmatism, chromatism, and spherical aberration. Fig. 21 shows a single lens Fig. 21. Fig. 22. Anastigmatic Lens Combinations of four glasses. Fig. 22 shows the glasses of a aouble, or rectilinear, lens of two single lenses having eight glasses in all. The art of the lens maker is a delicate one. A lens should be bought and used by the photographer, and not tampered with. 23 14 THE MOTION PICTURE A good lens should be kept in a dust-proof case when not in use. It may be brushed with a soft camel's-hair brush and wiped with soft clean tissue paper to remove dust— not a cotton or silk rag, which may carry grains of grit to scratch the surface of the glass. Shutters. AMien the camera is prepared for exposing a plate to an image, the lens stands as a window in the front of the camera. The purpose of the shutter is to close the lens window until the moment for exposure, then to open the lens and again to close it after sufficient amount of light has passed through to impress the image upon the sensitive plate. Cap. The simplest of shutters is the cap, which is a shallow box fitting closely over the front of the lens barrel. For exposures of several seconds or more in duration, the cap offers the most con- venient means, while for exposures of less than one-half second, the cap can hardly be removed and replaced cjuickly enough, and some sort of automatic opening and closing device should be used. Leaf. The leaf shutter consists of hinged leaves which meet and overlap to close the lens opening. They are forced open by a spring and forced closed by a spring. An exposure of as brief a space as yI^ second is feasible with the leaf shutter; and some shut- ters are advertised to make even shorter exposures. By the addition of an air piston, the closing of the shutter may be delayed until after the piston has completed a predetermined travel, thus giving an exposure longer than the shortest of which the shutter is capable. The usual "automatic" leaf shutter may be "set" before ex-posure to give an exposure of from one second to j\o second. The shutter may be adjusted also to hold the lens open until released. Exposures longer than one second may be made by the "time" adjustment, opening the shutter at the beginning of exposure and closing it after the proper lapse of time, as in the case of exposure with the cap. The leaf shutters usually work between the lenses, near the diaphragm. Curtain. The curtain shutter consists of two curtains on spring rollers inside the camera just behind the lens. When the shutter is adjusted for exposure, one of the curtains is in front of the lens; the other is above, rolled up. Upon release of the shutter, the lower curtain rolls down, opening the lens; after the desired lapse of time, the upper curtain unrolls and passes down, stopping over the lens and closing it. 94 PHOTOGRAPHY 15 Focal Plane. The focal plane of the camera is the position of the image formed by the lens. When ready for an exposure, the sensitive plate is located in the focal plane. The focal-plane shutter, which is a curtain just in front of the plate, is so called because it is placed as near to the plate as possible and, therefore, near the focal plane of the camera. The curtain has a slit which may be adjusted in width or it has several slits of different widths, ^^^len released the curtain rolls without stopping, and the length of time during which the light is permitted to shine upon the plate is determined by the speed of the curtain and by the width of the slot. With a shutter of this type, exposures as short as y-g^o ir second may be given. The shutter is available equally for longer automatic exposures and for time exposures. Testing. An automatic shutter has a scale for setting the speed of the shutter, usually marked 1, 2, 5, 25, 100, meaning, respectively, 1 second, § second, \ second, ^V second, and y^o second. The ex- posure given to the plate is not always true, however, to the value indicated by the scale of the shutter. The method of test is: Photograph with the automatic shutter at one of its settings an object Tnoving at a known speed; then calculate the length of time of the exposure from a measurement of the amount of movement visible in the photograph. The distance moved in the photograph is to the distance moved by the object during the exposure as the focal length of the lens is to the distance of the lens from the object. When the distance moved by the object and the speed of the object is known, the time required to move through that distance may be knoion, and that is the actual exposure of the shutter for the speed setting under which the test was made. A wheel driven at a constant and known speed may carry a mirror on its face near its edge, the mirror reflecting the light of the sun or of an arc lamp into the lens. In this case, the distance and focal length need not be measured; the angle of the arc which the revolving mirror makes upon the plate while the shutter is open will give the duration of the exposure for the shutter setting under which the test was made. Under test, a new fabulously high-priced leaf shutter showed an accuracy of only 60 per cent. Another cheap leaf shutter gave exactly the same length of exposure for its ^\ marking and for its 25 IG THE MOTION PICTURE j^iy marking, the exposure being ^\ second for either of them. A fair shutter test easily made is as follows: With stop f/ 11 and shutter speed gV expose a plate, and with stop f/64 and cap, time, or bulb exposure, give t and \\ seconds as accurately as possible. These exposures are nearly equal, and when developed in the same tray or tank the plates should be alike. The speed markings of a new shutter may be accepted as cor- rect; the medium speeds ^ and 2^5, which are used most by the ama- teur, are likely to be nearly accurate. The shorter exposures are likely to be too long; the longer ones are likely to be too short. An old or second-hand shutter should be tested for speed before good work is attempted with it. Plate=Holder. For experimental work for the purpose of gain- ing a knowledge of photography sufficient for the making of motion pictures or good still pictures, glass dry plates should be used. Cut films or roll films may be adopted later, but the more reliable glass dry plate should be used by the beginner. The plate-holder has two draw slides, and when each is drawn there is revealed a set of clamps for holding a glass plate inside the holder. The handle, or edge, of each slide is white on one side and black on the other. In the dark room, by dim ruby light, place a glass plate in each side, with the film, or dull, side facing out, and replace the slides, white side out. The plate-holders should be numbered on each side, the first holder being 1 on one side and 2 on the other; the second holder being. 3 on one side and 4 on the other, etc. \Mien exposing plates, always expose first the No. 1 side of the first holder, or the No. 1 plate, then the No. 2 plate, then No. 3, etc. Upon returning to the dark room for development, the subjects upon each plate will be remembered by remembering the order of the exposures, and it is likely that only one exposure will have been made upon each plate. Without some system for exposing plates in order, it is possible that upon development one plate will show a ship sailing through a forest, and another plate will show nothing but the fog of an imperfect ruby lamp. The camera is so arranged that the ground glass may be removed and the plate in its holder substituted. The removal of the ground glass may be by actually taking away the frame which holds it, but the more common method in small cameras is to force the plate- i PHOTOGRAPHY 17 holder into the camera in front of the ground-glass frame, the ground- glass frame being held by springs which yield to permit the plate- holder to enter. \Mien the plate-holder is removed subsequently, the ground-glass frame automatically resumes its proper position for focusing. Darkroom. The darkroom is a room which is not merely dusky, but a room which has absolutely no white light. It may have red light until it is far from dark, hence "darkroom" is but a name. It must not have any light which will affect the sensitive plate. No daylight. Windows, doors, and transoms must be examined for cracks. After remaining in a darkroom for a few minutes, cracks will be seen which were not noticed at first. A bathroom at night makes a desirable darkroom for photographic operations. A mov- able platform across the tub offers a work table, and running water is convenient. A ruby lamp must be purchased. If a satisfactory screen is made for the window, such a dark room may be used during the day. No white light must get to the plate except through the lens during the interval of exposure. A little practice enables the photographer to load his plate-holders by touch alone, no light being needed. This enables plate-holders to be loaded in daytime in any closet by a little care in closing the cracks around the door. A convenient darkroom may be built of rough boards in any corner of any room, basement, attic, or bam, the cracks being care- fully closed by papering inside and outside. A developing shelf should be the height of the waist. If nmning water is desired in the darkroom, a sink should be convenient to the developing shelf, but running water in any but a very large darkroom is an objection rather than an advantage. In the wall back of the developing shelf a window should be cut into which a sash is fitted carrying a ruby glass. Outside of the darkroom, on a shelf or bracket, should be the lamp for furnishing the ruby light, so placed as to shine through the window. Shelves for chemicals, apparatus, and supplies are outside the darkroom. -The darkroom contains nothing but a de- veloping shelf, a door, and a window provided with removable colored glass. Dishwashing, and other processes not necessarily darkroom processes, may be done elsewhere. Routine of Camera Operation. Select the view. Open lens. Open stop. Focus and manipulate the camera until you have upon 27 18 THE MOTION PICTURE the ground glass the image you want, no more, no less. Decide upon the stop opening to be used and the length of exposure to be given. Set stop opening. Close lens. Adjust shutter to selected speed setting. Insert plate-holder. Draw dark slide of plate-holder. Re- lease automatic shutter or otherwise make the exposure. Replace dark slide in plate-holder, black out. Remove plate-holder from camera. Practice this routine without plates in the holders, or without drawing the dark slide from the plate-holder, until entirely familiar with alt of the steps. ^Nlany plates are spoiled by drawing the dark slide before closing the lens, or by failure to draw the dark slide at all. PRODUCING THE IMAGE The picture is made upon the ground glass of the camera. If the photographer has the patience and skill, or the good luck as an amateur, to secure such an arrangement of his subject upon the ground glass as makes a good picture there, then the mechanical and chemical processes which follow will merely record that picture and will produce a pleasing photograph unless the record should be spoiled by accident. The view selected to be photographed often is forced upon the photographer. He must produce a picture of this house, or that bridge, or of the children of the family. The motion-picture camera man must photograph the set stage or such other subject as the producer in charge may direct. Yet the control of the image in nearly every instance is so completely in the hands of the camera operator that the resulting picture is better or worse as he is careful or careless, and according as he understands the possibilities of his camera to control the arrangement of the details of his subject. All of this control of the resulting picture, after the voluntary or enforced selection of the principal subject, must be exercised before the exposure of the sensitive plate or film is made by the operation of the lens shutter. After the lens has been opened upon the subject, transmitting the light of the image to the sensitive plate, no further change can be made in the picture. The making of the picture, that is, the making upon the ground glass the image which is to be recorded to become the finished photo- graph, may be divided into seven points for consideration t;nd study, as follows: 28 PHOTOGRAPHY 19 (1) The selection of the principal object to be photographed. (2) The selection of a background or setting for the principal object. (3) The lighting or direction of light falling iipon the subject as a whole. (4) The size of the principal object in the image. (.5) The composition and balancing of principal and subordi- nate objects in the image. (6) The prominence of the background. (7) The avoidance of disagreeable distortions in the image. Principal Object. The total task of photographing usually is the making of a photograph which may be used to record some one object, such as a house, a tree, a flower, a person, or an animal. Sometimes it is merely "a pretty scene," but in this case the pho- tographer should decide upon some object of the scene to form the principal object of the picture. He should give such prominence to some object that the resulting photograph will be in substance a pic- ture of that principal object, yet will embody in its background or scenic setting the "pretty scene" which it was desired to photograph. Right at the beginning, and in the most fundamental of all of the principles of picture making, the camera operator has the power to control the image, to make or spoil the picture, even though com- manded by an outside influence as to his general subject. Whether he is inspired by the beauty of a scene to make a photograph of it, or whether he is commanded by a companion or by an employer to make a photograph of it, he still has the power to make some object a principal object, to hold other objects subordinate to it, and to mold the whole into an arrangement in the image on his ground glass which will result in a photograph worthy the name of a picture when finished. Each picture must have a principal object or it is at best only a photographic memorandum. Background. In portrait work in a studio, the backgrounds are painted as desired, and brought in or carried out, and turned and placed as needed. And for scenic w'ork it is almost the same. Suppose that it is commanded that a photograph be made of a rose- bush in blossom in the front yard of a house. If the house would form a desirable background, set up the camera at the front fence. If the front fence would form a desirable background, photograph 29 20 THE MOTION PICTURE the rosebush from the house. If either side fence is better, place the camera at the opposite side of the yard. If none of the surround- ino-s are pleasing as background objects, there is still the possibility of viewing the bush from above so that the grass of the lawn, and not any fence, house, or other object is included as a background. This view may be had from the top of a stepladder, from an upper window of the house, or even from the height of the tripod above a porch floor. With some of these background arrangements surely the resulting picture will be better than with others. Get the best one, just to show that you are master of the camera, even though some one else dictates what your principal object shall be. AMien photographing persons or animals, the "principal object" usually may be brought to a suitable background. When photo- graphing a house, the inclusion in the image upon the ground glass of a little more of the foreground, or of a little of one of the houses standing at one side of the "principal object," or of a tree standing near, partakes of the fundamental principle of the selection of a back- ground and gives the camera operator some power to make his image nearer to a picture and farther from the memorandum type of photograph. Lighting. With immovable objects, such as trees, houses, and rosebushes, illuminated by the sun, the photographer has two methods of controlling his lighting, both of which consist merely in taking advantage of natural conditions by the selection of the proper time for making the exposure. The sunlight falls upon the object at dif- ferent angles and in different directions at different hours of the day. Whether the ol)jcct is photographed in the early morning, in the late morning, at noon, or in the afternoon is usually within the con- trol of the photographer, and it makes a difference in the pictorial value of the photograph. Few landscapes are pretty at noon, with the shadow exactly under each tree and bush; they are far better between two o'clock and five o'clock in the afternoon. The horizontal rays of sunlight become objectionable again in the late afternoon. The second method of control for immovable objects is the selec- tion of an overcast or hazy day in preference to a day of direct sun- light. Usually the direct sunlight, with sharp shadows is preferable, but here again the operator has control of the image in his hands. Size of Object. The size of the princi])al object is controlled by 30 PHOTOGRAPHY 21 the distance from the camera to the object and by the focal length of the lens. The nearer the camera is carried to the object to be pho- tographed, the larger will be the image of that object upon the ground glass. The longer the focal length of the lens used, the larger will be the image upon the ground glass. The image of the main object, therefore, may be enlarged by using one of the lenses alone instead of both of them double. Composition and Balance. By the terms composition and balance reference is made to the many relations which exist among the masses of light and shade among the lines of the image. The rules are so numerous that all of them cannot be followed at all times, and many of them apply only to specific instances of subject arrange- ment. A few of the more general rules may be kept in mind when arranging the image upon the ground glass. A profile portrait shows on one side the light face against the darker portion of the background, and on the other side the dark hair against .the lighter portion of the background. Each side of the picture has its lights and its shadows. A landscape, even the picture of a building, should bear the same analysis. A balanced picture should have a principal shadow, and some minor shadows. It should have a principal high light and some minor high lights. With the principal shadow and the minor high lights on one side of the image and the principal high light and minor shadows on the other side, it is likely that an approximate balance will be obtained. For example: a heavy mass of foliage is at the lower right, as a near bush or tree: a few scattered masses are at the middle left and upper left, as distant bushes or trees; a roadway or stream runs from lower left to upper right, showing a large light spot at lower left and smaller light spots at upper right; the large light is a little higher or a little lower than the large shadow, not dead level that a line connecting them would be parallel to the margin. That sounds like a coldly critical analysis suitable for producing a stiff and formal picture, yet a scene sought out in nature and photographed from a viewpoint care- fully selected to secure this arrangement of lights and shadows will rank above a hand-camera snapshot and will repay the amateur's effort. In a water scene, a ship at anchor may be photographed from the pier with another pier in the background. Place the dark hull of the ship near the lower edge of the picture and at the right of the SI 22 THE MOTION PICTURE middle line; place the distant pier above the center on the left of the picture. The masts of the ship cut up into the upper right corner and break up the sea and sky into minor high lights. The major high light is the unbroken sea at the left of the ship, lower left corner of the picture. Strictly parallel lines are objectionable in a picture unless they are parts of an object and unavoidable, as the masts of a ship. Any line parallel to the margin of the plate is objectionable except the side lines of buildings, which are unavoidable. An imaginary line joining two high lights or two shadows should not be parallel to an edge of the plate, nor should an imaginary line from the principal shadow mass to the principal high light be parallel to any edge of the plate if it can be avoided. The horizon Une requires care in this detail. Horizon Line. The placing of the horizon line has much in- fluence in the composition and balance of the picture. Care must be taken that the horizon line does not cross the principal object at an undesirable point, nor should the apparent horizon divide the picture exactly in the middle. Where a hillside is included in the landscape, it may be made to give an inclined or irregular line for the horizon. Where a level horizon is unavoidable, it should be broken if possible by the objects of the picture. Point of View. The point of view is the location of the camera whence the image is made. Changing the point of view is the most powerful means which the camera operator has for arranging and controlling his image. The selection of the background depends almost solely upon the point of view chosen. The size of the prin- cipal object is largely controlled by the choice of the point of view, while the composition and balance are almost wholly controlled by the selection of the point of view, together with the selection of the lens length. Prominence of Background. As a rule, the image may be separated into principal object and background, even though the background or setting of the principal object be really the more important portion of the picture, and the portion primarily desired. The relative size of the principal object and its associated background objects may be controlled by the lens length. With the double lens, focus upon a view containing a near tree as a principal object. Note the size of the distant trees. Remove the front lens cell, move 32 PHOTOGRAPHY 23 the camera back to twice the distance from the principal tree, and focus again. By the change of the lens and the change of the point of view, the principal tree will be the same size as before; note that the distant trees are much larger than before, thus giving greater prominence to the objects of the background. Also, by the use of the longer focus of the single lens, less of the horizon is included in the image, and less of the surrounding landscape is shown as a background to the principal tree, that which is included in the image being shown in larger size. If the front and back cells of the lens Fig. 23. Perspective Distortion are different in length, the front cell alone will give still more prom- inence to the background objects, a greater extension of bellows and a still more distant viewpoint being required to keep the principal object at the original chosen size. When it is impossible to secure a point of view near enough to the principal object to secure a large image, the longest lens will give the largest possible image. In the case of a portrait, the background is entirely unimportant in detail, and is most satisfactory when shown merely as a blurred surface of light and shade. This is effected by opening the diaphragm to its largest stop size, then bringing theJace of the portrait to a sharp 33 24 THF MOTION PICTURE ocus. The -background will be blurred because it is "out of focus." Out-of-door portraiture profits by the same rule, and the rule applies generally where the picture is to be a photograph of a specific object and the background is not a part of the object. ^Yhere both fore- ground and background are required to be sharp, a small stop opening must be used to secure the result. Distortions. Usually, any distortion of the image caused by the lens is objectionable. Blurring the background in portraiture and similar pictures by using the shallow field incidental to the large stop opening is in itself a form of distortion which is made to serve a useful purpose and is an aid to the operator in the control of his image. Barrel distortion and pin-cushion distortion, which have already been discussed, should be avoided as far as possible, particularly in architectural subjects. Perspective distortion will be observed if the camera does not stand level upon its tripod. In landscape \dews, such distortion FipT. 21. Camera '"Mi SAing Back Fig. 25. Camera with Rising Front in Use in Use usually is negligible. In architecture it is ludicrous, Fig. 23. The remedy is to keep the ground glass vertical, or nearly so. This is done by the swing back and by the rising front. Swing Back. When the back of the camera, carrying the ground glass and the plate-holder, is pivoted or hinged, the body of the camera may be tilted to bring the desired scene upon the ground glass, and the swinging back of the camera then may be adjusted to bring the ground glass vertical or nearly so. Fig. 24. By this adjustment, the perspective distortion will be corrected, but the focus is more 34 PHOTOGRAPHY 25 difficult and a smaller stop opening will be required to give a sharp focus over the entire plate. Rising Front. With the camera placed about level, more of the sky or more of the foreground may be included upon the plate by raising or lowering the lens in the front of the camera, Fig. 25. This avoids perspective distortion, but the amount of adjustment thus obtainable is somewhat limited. RECORDING THE IMAGE The recording of the image consists of two processes — expos- ing the sensitive plate and developing the exposed plate into a negative. Dry Plates. The art of the chemist is brought into use in record- ing the image of the lens. The known substance most sensitive to light is finely divided nitrate of silver suspended in gelatine. The manufacture of this substance is not attempted by the photographer. A thin skin of the prepared gelatine is spread upon glass plates and dried. The plates thus made are sold under the name of photo- graphic dry plates. These are bought by the photographer in light- proof sealed packages and loaded into plate-holders in the darkroom. Films. Flexible transparent celluloid films coated with the prepared gelatine are used instead of the glass, if desired, and may be had for pictures up to a 5 by 7 size, either in packets of cut films or in rolls of proper width on which exposures may be made one after another. In motion-picture work, the celluloid film is a necessity and it is used universally in commercial motography. Exposure. \Yhen the plate-holder is inserted in the camera, the lens closed, and the dark slide withdrawn, the lens is opened just long enough to permit a sufficient amount of light to pass through the lens to affect the sensitive silver of the dry plate — neither too much, nor too little. This process of administering to the plate the proper dose of light in the form of the image is called exposing the flaie. The greatest problem in photographing any subject is the best arrangement of the image upon the ground glass, and the next greatest is the determination of how long a time, in seconds or frac- tions of a second, to permit the light to flow through the lens to impress the image properly upon the sensitive plate. The amount of light from a given subject which falls upon 35 26 THE MOTION PICTURE the sensitive plate to impress the image depends upon the size of the stop opening and the length of time during which the lens is left open for the exposure. Light flowing through the stop opening is just like water flowing through a hole. If you increase the size of the hole, the bucket will be filled with water in less time, and in direct proportion to the change of the size of the hole. Double-size hole, half the time to fill the bucket. Half-size hole, double time to fill the bucket. A hole ten times the size will fill the bucket in one-tenth the time. This rule holds strictly true in the case of the photographic exposure. Increase the size of the stop opening and the light passes through faster, giving the plate sufficient light in a shorter time. A larger plate requires a greater quantity of light because there is more surface to be worked upon, The Hght spreads from the lens, and the farther back from the lens the light must go to reach the plate, the more it spreads out and the weaker it becomes. The lens length has a direct influence in the strength of light upon a plate from a given subject through a given opening or, to state the same rule differently, the lens length has a direct influence in determining the size of stop opening which mv^t be used to effect the same strength of light upon a plate from a given subject. Stop Numbers. A plan of numbering stops according to the size of the opening has been devised which removes the actual focal length of the lens from the calculation of the strength of the light upon the plate, by including the focal length of the lens in the deter- mination of the stop number. There are in common use in America two systems of stop numbers — the focal-factor system and a modifi- cation called the uniform system. The plan used in the focal factor system consists of numbering the stops in fractions, as 1/8, 1/16, 1/32 of the focal length of the lens; these are written //8, //16, //32, etc., or F/8, F/16, F/32, etc., or /-8, /-16, /-32, etc., or /:8, /:16, /:32,etc. The stop number //16 means that the diameter of the stop opening is 1/16 the focal length of the lens. An //16 stop for a 4-inch lens is 1/4 inch in diameter. An //16 stop for an 8-inch lens is 1/2 inch in diameter, giving four times the area of the stop open- ing, giving four times the quantity of light, but since the light goes twice as far before it reaches the ground glass or sensitive plate it will spread over four times the area and, therefore, will be of the 36 PHOTOGRAPHY 27 same strength, or intensity, on the plate with the 1/2-inch stop //16 of the 8-inch lens as with the 1/4-inch stop //16 of the 4-inch lens. This is of great convenience in writing of exposure timing, because by the use of the focal-factor system of stops all the rules given for exposure will be true for cameras of all sizes and for lenses of all lengths of focus. In both systems each stop number requires either double or half the exposure of the next stop number, the stops being alike at //16 and No. 16. If the stop numbers on a scale are 4, 8, 16, 32, 64, 128, 256, it is "U. S." or uniform system. If the stop numbers on a scale are 8, 11, 16, 22, 32, 45, 64, it is focal-factor system. In either case, as the numbers increase each number requires double the time of exposure required for the preceding or next smaller number. In any lens, the largest opening possible may not be an even stop number, and this first marking of the scale may vary from the "double time" rule. Thus, if a lens will work with an opening of //7, its scale will be marked 7, 8, 11, 16, etc., if for the focal- factor system; or 3, 4, 8, 16, etc., if for the "U. S." system. In Table I the numbers in the two systems are compared. TABLE I Equivalent Stop Numbers in Focal-Factor and Uniform Systems f/2 f/3.5 f/4 f/4.5 f/5 f/o.6 f/6.3 f/7 No. i No. 1 No. 1 No. U No. U No. 2 No. 2i No. 3 *f/S *f/ll *f/16 *f/22 *f/32 *f/45 f/64 f/90 No. 512 No. 4 '"No. 8 No. 16 No. 32 No. 64 No. 128 No. 256 *The stop numbers in the two systems which are most commonly met and used. Plate Speed. Some plates are coated with a gelatine film which is more sensitive to light than others. As a standard, plates such as Seeds 26x, Stanley, Hammer Fast, Cramer Instantaneous Iso, and Standard Extra may be taken as most suitable in speed for amateur work. These plates list 130 on the Watkins scale of plate speeds. A faster class of plates comprises Cramer Crown, Hammer Extra Fast, Seed 27, and Kodak and Premo Films. These list at 180 on the Watkins scale and require only three-quarters the exposure to impress the image as fully as upon a plate of the 130 class. 37 28 THE MOTION PICTURE Light Intensity. In filling a bucket with water running through an opening, the pressure which is behind the water will influence the rate of flow and will influence the time required to fill the bucket. The intensity of the light which illuminates the subject and the nature of the subject itself are the two elements which influence the rate of flow of light through the lens opening. On a dark day the light does not pour through the small stop opening as fast as on a day of Winding sunlight. Even in the same bright sunlight, the quantity of light sent to the camera from a dark green tree is less than the quantity sent from the white sails of a ship. One considera- tion of the nature of the subject also is its distance from the camera. If the average amateur photographer were asked the exposure for a summer landscape, he would probably say, carelessly, //1 6 and 1/25 of a second. That is the hand-camera way and gives but twenty good negatives out of a thousand exposures. The intensity of light depends upon the height of the sun above the horizon, which varies with every day of the year and with every hour of the day. With a clear sky and an average subject. Table II gives in seconds the proper exposure (Watkins 130 list plate) for //16 stop for each hour of the year, by months, for the latitude of the northern portion of the United States. In the southern portion of the United States, three-quarters of this exposure is sufficient; and on the equator, probably one- half is sufficient, and the May-June-July column may be used all the year around, with the 5 a. m. and 7 p. m. figures omitted. For a hazy day — good daylight but cloudy enough to obscure the sun — give double the exposure as a correction for the clouds. On a heavily overcast, gloomy day, give four times the exposure as a correction for clouds. Nature of Subject. The nature of the subject to be photographed has an influence even greater than the time of day or condition of the clouds. For pictures in the middle of the day, a glance at the table shows that the midwinter exposure with sun is but little more than double the midsummer exposure with sun. The exposure for cloudy days is only twice or four times that for sunny days. But the correction for the nature of the subject even with outdoor subjects may be two hundred times as much for one subject as for another. The following corrections may be applied to Table II to com- 88 PHOTOGRAPHY 29 TABLE II Day and Hour Exposure Chart A. M. P. M. Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. 5 A.M. 1 6 A.M. 1 1/2 1/5 1/2 1 7 A.M. 8 A.M. 2 1/2 1/5 1/10 1/10 1/10 1/5 1/2 2 2 1/2 1/5 1/10 1/10 1/10 1/10 1/10 1/5 1/2 1/2 9 A.M. 10 A.M. to 2 P.M. 1/5 1/10 1/10 1/15 1/15 1/15 1/10 1/10 1/5 1/5 1/10 1/5 1/15 1/15 1/25 1/25 1/25 1/15 1/15 1/10 1/10 3 P.M. 1/10 1/10 1/15 1/25 1/25 1/15 1/10 1/5 1/5 4 P.M. 1/2 1/5 1/10 1/10 1/15 1/15 1/10 1/5 1/2 1/2 5 P.M. 2 1/2 1/5 1/10 1/10 1/10 1/5 1/2 2 2 6 P.M. 1 1/2 1/5 1/2 1 7 PM. 1 1 1 pensate for the difference in the character of the subject of different images. 1/20 exposure for sky and clouds, where the foreground objects do not form a part of the picture. 1/10 exposure for sea and sky, ships at a distance at sea, views at a distance across the water. 1/4 exposure for open views, where the important portion of the view is in the distance and the foreground is unimportant. 1/2 exposure for very light objects of importance in the foreground. Exposure time given in the table is suitable when the important objects of the image are 20 to 100 feet from the camera and are neither white nor black, neither very light nor very dark. Twice the exposure time given in the table for objects nearer than 20 feet, or for dark objects of importance in the foreground of the image. Four times the exposure time for portraits in shade of heavy foliage, and for dark objects nearer than 20 feet. Sixteen times the exposure time for pictures in dense woods where side light as well as top light is obstructed by the foliage of the trees. Near sunset, five times the exposure in order to compensate for the yellow color of the sunset light. Interiors, if very well lighted by windows and with light walls, 100 times the table values. Interiors, if not well lighted, 500 to 5,000 times. When the sun is in front of the camera so that the shady side of the subject is being photographed, the exposure should be doubled. 39 30 THE MOTION PICTURE Calculation of Exposure by Table. To calculate an exposure requires that the proper //16 time for average plate and subject be taken from Table II. If the subject is an average one and the sum- mer day is bright, then there is no correction to be appUed, the stop is set to //1 6, and the figure taken from the table is set upon the automatic shutter and the exposure is made. A few exceptions may be studied. The summer hotel presents from across the valley a view which the visitor wishes to take with him. At one point in the road a group of trees between the road and the hotel obscures the hotel, but by taking a viewpoint farther along the hotel is free from the ob- struction and the group of trees at one side of the middle of the image balances the hotel at the other side. The trees being nearer and larger are the "main object" of the com- position, but the building is the more important. It is painted white. Trees behind it show its outline definitely, and both the trees behind and the "main object" group of nearer trees break the horizon line. The horizon line is placed high — three-fifths from the bottom and two-fifths from the top line of the picture. If possible, the cam- era is so positioned by its selection of viewpoint that some small object breaks the foreground on the side opposite the "main object" group of trees. The ex- posure is: Summer, 2 p. m., by Table II, 1/25 second; important portion of the view is in the distance and foreground unimportant, correction 1/4; the exposure should be 1/100 second at //16, but better 1/25 second at //32 to increase the sharpness of the distant object. /// a light subject, give less rather than more time than given in the table. Further along, the visitor passes through a wood and notes a clump of pretty ferns. The table says 1/25 second; correction for deep wood, 16; correction for dark color (green) of ferns, and near the camera, to have the image of the ferns large, 4. Time 04/25 or Fig. 26. Watkins Exposure Meter 40 PHOTOGRAPHY 31 2^ seconds at //16. In a dark subject, give too much rather than too little time by the table. Exposure Meters. The exposure meter is a device for measur- ing the strength of the light which falls upon the subject. It takes the place of Table II and of the correction for the clouds. Two types of exposure meters in general use are the Watkins, Fig. 26, and the Wynne, Fig. 27. The principle of both meters is the same. A disk of paper which is discolored rapidly by light is movable behind a slot, and beside the slot are bits of color which the paper matches in the course of its discoloration under the influence of light. The more intense the light, the more rapidly does the exposed bit of the paper disk become discolored, and the sooner does it reach a tint which matches one of the bits of color adja- cent to the slot. The time required to match the darker color is taken as ac- tinic value of the light. An exposure- calculating disk forms a part of each meter. Upon and near the calculating disk are sets of figures for (a) the ac- tinic or meter value of the light, as noted in the number of seconds which is taken by the paper to discolor to match the dark standard tint; (b) the speed of the plate which is to be used in the ex- posure; (c) the diaphragm stop; and (d) the required exposure in seconds or fraction of a second. The difference between the two meters is found in the cal- culating device. In the Watkins, the stop number is set opposite the plate number; then opposite the time required for the paper to darken is found the time required to impress the image upon the plate, that is, the exposure time, to which the correction for the nature of the subject must be applied. This appears to be the more convenient meter for the amateur either with hand camera or tripod. In the Wynne, the time required by the paper to darken is set opposite the speed number of the plate; then opposite the stop number is read the required exposure for a standard subject, to which the cor- Fig. 2t. Wynne Exposure Meter 41 32 THE MOTION PICTURE rection for the nature of the subject must be appHed. This is the more convenient for the motion-picture camera operator because of an exposure Hmitation in the motion-picture art. The Wynne meter is preferred by many fixed camera operators who have be- come familiar with it. Full instructions for use accompany either meter when purchased. There are also upon the market many exposure meters, so- called, which are but calculating devices for combining the date table with the cloud correction, subject correction, stop number, and plate speed. Perhaps, when facility has been acquired with one of them, it would be found convenient. Exposures with Single Lens, ^^^len the front lens of a double lens is removed, for the purpose of obtaining a larger image, or to increase the prominence of the background, the focal length of the lens has been changed, without changing the marldngs of the diaphragm scale; these markings, therefore, are not correct for the sinde lens. To obviate this, some lenses have two or three sets of markings on the diaphragm scale, one for the double lens and one for a single lens if both singles be of the same focal length, while if the singles be of different focal lengths there may be three mark- ings, one for the double lens and one for each of the singles. Where the singles are of the same focal length, the exposure time for a single lens will be four times that for the double lens with the same stop setting, to compensate for the difference in focal length between double and single. Wliere the singles are of different focal lengths, the exposure for the short single will be three times that for the double lens, and the exposure for the longer single will be six times that for the double lens. Duplicate Exposures, ^^^len much is in doubt, and upon sub- jects which cannot be photographed again, two exposures may be made, using two plates, and giving different lengths of exposure. If the range of exposure is such that one plate has ten times the exposure of the other both may give good negatives, whereas, if this ratio is increased to twenty-to-one, disappointment may be met by finding one plate under-exposed and the other over-exposed. As an over-exposure is a better printing proposition than an under exposure, a good rule for duplicate exposures is as follows: 42 o H » O « s ^ H o (« -5 & t) O ^'^^ « a, e M J n, H *^ S Z & c tii K O j^A oar ^S; o >i O g o o « I W ^ H J o 4 H - ^ ^, < a. « ?, O o Pi O W MOTOGRAPHY 23 TITLE A Trip Across Lake Michigan PLOT A trip beginning in Chicago and ending in South Haven, Michigan, via steamer "Westland," showing something of fruit traffic. SCENARIO Cast of Characters None Scene Sets None Special Synopsis Title: "Chicago River." Scene 1. Panorama from one of the bridges, showing large passenger steamers at dock, showing particularly the Westland, on which the trip is to be made. Scene 2. Tiirning of a bridge and passing through of a large freight boat. Scene 3. Leaving of the little passenger boat on its frequent trips down the drainage canal. Title: "Away for Vacation Days." Scene 4. Ticket window, people buying tickets. Scene 5. Gangplank of steamer, people going aboard. Title: "Leaving the River." Scene 6. Travel scene from bow of boat, showing opening of Rush Street bridge to let boat through. Better make this with trick handle, half speed. Show also points of interest on banks of river and lighthouse on pier at mouth of river. Title: "Chicago Water Front." Scene 7. Panorama of Chicago water front. Make this from the outer breakwater, two or three camera stands if necessary. Title: "Out of Sight of Land." Scene 8. Panorama of waves, showing details of boat structure, sweep- ing the horizon rapidly from stern of boat to stem without showing land. Title: "South Haven, Michigan, Breakwater." Scene 9. View from bow of steamer as vessel approaches the mouth of the river. Trick handle probably. Title: "South Haven." Scene 10. Panorama of South Haven water front. Make from light- house at end of pier. Title: "Oh! There you are!" Scene 11. Passengers disembarking from boat. Greetings by friends. May require some posing and stock actors. Title: "Off for a Day on the Farm." Scene 12. 'Bus, loaded, driving down village street, passengers waving to camera man. 91 24 THE MOTION PICTURE Title: "Peaches." Scene 13. Peach orchards, picking peaches, packing in baskets, haul- ing to town, loading on steamer for Chicago market. Grapes, plums, anything that can be had of the fruit industry. Several scenes. Title: "South Haven .\musements." Scene 14. Dance pavilion, roller coaster, the little launch on the river loaded with passengers. Several scenes. (End of picture.) The picture-show patrons like the dramas and comedies and as a rule find the travels tiresome. They demand the dramas and make caustic remarks about the dry travels. The theater managers get this sentiment from their patrons and, in turn, take it to the film exchanges, refusing travels sometimes when offered for exliibition. The film exchanges, in turn, carry this sentiment to the manufac- turers. The result is a strange dodge on the part of the film manu- facturers, producing W'hat might be called a travel and drama or travel and comedy. It is produced by combining something of a dramatic or comic nature with the scenery which is to form the sub- ject for the travel picture. SPECDIEX TRAVEL AND COMEDY SCRIP The following is a specimen scrip for such a film picture: TITLE Sammy at Niagara Falls PLOT A scenic review of Niagara Falls. Sammy takes a train and arrives at the Falls. In recording Sammy's adventures at the Falls such scene sets are chosen as to do the falls completely SCENARIO Cast of Characters Sammy, ordinary dress except a comical cap Office help Visitors at Falls for passers-by business Scene Sets Office scene Bedroom, poorly furnished A railway station Another railway station, with sign, "Niagara Falls" Natural scenery at Niagara Falls, New York Synopsis Tide: "Sammy is Off for a Vacation." 92 MOTOGRAPHY 25 Scene 1. Office, with Bookkeeper and Typewriter Operator. Discovered, Sammy, bookkeeper, stenographer, other help. Sammy in great glee, talks to all, serially, makes more confusion than headway with his work, bookkeeper hands him pay envelope, Sammy tears open and takes out money, waves money in glee, gets hat, exit, all stopping work and waving adieu. Title: "Where Shall I Spend My Vacation?". Scene 2. Bedroom. Enter Sartimy, in glee, carrying newspaper. Takes off hat and coat, sits, feet up, reads paper with frowns, suddenly great glee, holds up paper. Title: "Newspaper Page, showing advei'tisement, railway to Niagara Falls and return $4.60, tickets good one week." {Buck to Scene 2.) Sammy throws down paper, takes hat and coat, takes money from pocket and replaces it, exit. Scene 3. Raihvay station platform. Enter Sammy, paces platform impatiently; enter supes and passers-by. Enter train, Sammy gets on board, exit train. Scene 4. Raihvay station platform, with station sign "Niagara Falls," Enter train. Enter passengers leaving train, Sammy last, exit Sammy one side. Scene 5. Panorama of the Falls, from any convenient elevation, such as balcony at Windsor Hotel, Canadian side. Scene 6. Prospect Point. Shows American Falls and protecting rail- ing at Prospect Point. After panorama to show scene, when scene is nearly out, enter Sammy with fish pole and l^egins to bait hook. Scene 7. The stone bridge. "\Miile panoraming the bridge, Sammy nearly gets run over by a rig while walking around in the roadway with a tin cup looking for water, stage business of thirst. Scene 8. Terrapin Island. View from Goat Island, showing bridge to Terrapin Island, panoraming for view. As view nears end, Sammy comes out half way across Terrapin Bridge with a string on his tin cup, lowers the cup into the water, hauls it up and gets a much satisfying drink. Scene 9. ^laid of the Mist. Show boat at dock, and passengers in- cluding Sammy passing aboard. Falls in background. Scene 10. Camera on board the Maid of the Mist. Near view of the Falls. Sammy appears at rail in near foreground of camera and is deathly seasick. Scene 11. Cave of the Winds. Panoram for view, then pick up Sammy and panoram him half way across the bridges between Goat Island and the Cave of the Winds. He becomes afraid and turns back. Again attempts it, but again turns back, this time finally. Camera keeps him in field continu- ously. (End of Picture.) Such a combination enables the film manufacturer to render his travel pictures more acceptable to that class of patron disliking the travel in its pure form. The exhibitor also has opportunity to advertise the picture in his theater front announcement either as "A Roaring Comic" or as "A Beautiful and Wonderful Nature Picture." 93 26 THE MOTION PICTURE SPECIMEN INDUSTRIAL SCRIP To depict an industry completely sometimes requires pictures taken in various parts of the world. "The Rubber Industry" should begin with views of the tropical rubber trees, curing the sap for shipment and loading on vessels. Then the scene shifts to the northern factory, the processes of bringing the rubber into commercial shape and the manufacture of some well known article wholly or largely composed of rubber. The picture may close with a scene showing manufactured article in use. The scenes taken inside the factory doubtless would require artificial lighting. An industrial film well done sometimes involves scenes of great difficulty, and even trick pictures. The following specimen scrip calls for the "stop" picture. TITLE Raising Watermelons PLOT Preparing the ground and planting. Then a growing vine by stop pic- ture. Picking, loading, hauling, loading cars, freight train in transit to city, melons on sale in city store front. SCENARIO Title: "Preparing the Ground." Scene 1. (Select a scene with picturesque background, showing gate from field to highway. Take camera stand to panoram field, gate and high- way, including background objects. Build permanent camera stand, that the identical position of camera may be taken from time to time.) Plowing and fertilizing in the fall. Scene 2. From same viewpoint, a snowstorm scene. Scene 3. From same viewpoint, a sleigh passing on the highway. Title: "In the Spring, the Work Begins Again." Scene 4. From same viewpoint, spring plowing. Scene 5. Forming the hills for planting. Scene 6. Planting the seed. TitU: "The Growing Plant." Scene 7. Stop picture, studio. The hand planting the seed, the breaking of the plant through surface of earth, growing hourly to blossom. Scene 8. Stop picture of field. Scene 9. Stop picture of near view of melon. Title: "Selecting the Ripe Fruit." Scene 10. View of field with man working, testing melons for ripeness. As he comes near the camera, his tests are clearly seen, and the cutting of the stem and turning up of the white side is shown. 94 MOTOGRAPHY 27 Title: "On the Way to Market." Scene 11. Wagon in field, loading the selected melons. ScEisfE 12. Panoram loaded wagon through gate and along highway. Scene 13. Near shipping point, many wagons, all loaded. Scene 14. Loading the melons into railway cars, showing method of handling. Scene 15. The melon farmer gets the money at the car door from the shipper. Scene 16. From the caboose of a railway freight train, showing train ahead and scenery passing by, running through rural district. Scene 17. Same, entering large city. Scene 18. City store front, melons on sale. Lady enters and buys. Delivery boy puts purchased melon in basket and exit carrying. (End of Picture.) Who is the Author. Usually, it is the producer. Surely no author is better qualified to write within the limitations of the motion- picture art than the producer. Surely no producer is better able to interpret a story than the author. In industrials, the producer may look over the situation in the capacity of author and write the scrip in memorandum form as his field notes for working with the camera. With the notes in hand, he takes the camera man and equipment and makes the various scenes which his notes show pos- sible or desirable. In travels, comedy, or. dramatic accompaniment, the field should be looked over to leam its possibilities, and no one is better qualified than an experienced producer. In current events, an experienced producer is the best judge of advantageous view- points. In chases, the central idea, the joke of the picture, may be sufficient information to pass from the author to the producer, the producer providing scenes to embody the thought in a picture within the limitations of the art and his immediate environment. It is in comedies and dramas that the author as such may be entirely remote from the producer. Scrips for comedy and drama may be written as short stories are written, and may be submitted to film manufacturers as short stories are submitted to magazine publishers. THE PRODUCER The producer is in charge of the studio, of the scene painters, of the sign writers, of the stage carpenters, of the property man, of the actors, and is nominally in charge of the camera men. When the producer undertakes a picture, the scrip is made as complete as he desires by adding details of scenes, notes of probable 95 28 THE MOTION PICTURE location of outdoor scenes, names of actors suitable for the parts or notes on actors required to be found for the parts, as well as notes on other pictures being; produced or to be produced contemporane- ously with the scrip being studied. Studio stage sets and scenery recjuired are noted and a property list is made. The titles also are noted, for title making is a part of the work quite distinct from scene making. The producer keeps all his departments running as smoothly as possible, the motion scenes for a drama being produced this week while titles are being made for another drama for which the motion scenes were produced last week, and the stage carpenters and scene painters are at work upon studio settings and properties for still another drama for which the motion scenes will be produced in the weeks following. The order of producing drama is: (1) Painting the scenery for the studio sets, for none but the simplest scene sets are used repeatedly. (2) Getting the properties and costumes. (3) Getting the actors and rehearsing and photographing the motion scenes. (4) Producing the motion scenes before the camera. (5) Inspect- ing the proofs of the motion scenes, retaking unsatisfactory scenes and making additional scenes which may seem desirable — some- times, alas, only for "padding" — ^after the author's scenes have been reviewed. (G) Rewriting the scrip if necessary to fit the drama as embodied in the motion scenes. (7) Writing the titles finally and in detail. (8) Making the titles. (9) Adjusting lengths of titles and scenes to make the desired total picture length. Studio Scenes. The scenerv used for setting the stage diflFers from the scenery of the dramatic stage by the absence of color. Plain black and white and neutral tints are most desirable, for color is objectionable in that it may be misleading in tone values when photographed. The'scenery required is only sufficient to fill the field of the camera. Usually when staging an interior, but two walls of a room are shown. In such a case, the third wall is not needed in the scene set, nor arc flies needed for the ceiling. Wall scenery may be made in sections or panels. Fig. 2, and the sections may be set together as desired, making possible the use of the same painted work for several scene sets sufficiently different from each other. If a spectator should recognize any scene as being familiar because 96 MOTOGRAPHY 29 97 30 THE MOTION PICTURE of prior appearance in other dramas, the first thought would be that the film then being viewed is an old one. To avoid this, strik- ing scenes and highly special scenes, Fig. 3, are used but once. Only the more ordinar}- and characterless scenery may be used repeatedly. In Fig. 2, which is a good example of scenery for repeated use, five "flats," each so small that they resemble the "wings" of a dramatic stage setting and each only sufficient in height to cover the film win- dow in the image in the camera, are shown combined for a scene Fig. 3. View of Indoor Studio, with Stage Setting for Outdoor Scene set. When rearranged with the door at right or at middle back, new and sufficiently different sets are produced for use in another drama, while with the addition of a flat having a window, still further com- binations may be made to use the scenery to its limit before re- painting. A set of scenery- flats so designed as to be papered with wall paper may be changed beyond recognition in a few minutes and at a very small expense merely by giving them a new dress of figured paper. For wall paper, the flats should have a width proper to take exactly two or more full width strips of wall paper, and the paper should be applied so that the figures will match at the edges when the flats are set together. Otherwise, the effect is ludicrous. 98 MOTOGRAPHY 31 99 32 TtiE MOTION PICTURE In addition to painted scenery for the studio, which may rep- resent either an interior or an exterior scene, painted scenery some- times is used for outdoor staging. Fig. 4 shows a scene set from a production of "Richard III/' made by the Vitagraph Company. The camera stands in the foreground of the ilkistration, facing the scene set. The field of the image in the camera does not extend to the right and left beyond the painted scenery representing the stone wall, hence in the motion picture there is given the effect of an in- definite stone wall having the arched entrance. Behind the arch is Fig. 5. Natural Scene Setting, Outside of Cottage a flat scene with houses and clear sky. This is a painted scene also, placed against the tight board fence which runs across the view at the foot of the railway embankment. Beyond the railway embank- ment are trees, the tops of which appear above the painted stone wall. In Fig. 2 and Fig. 3, the image in the camera does not extend above the top of the painted scenery; in Fig. 4 the camera includes the top of the wall and a strip of the sky above, an effect which in the studio would recjuire a strip of sky scenery above and behind the wall. The setting of Fig. 4 is properly called a studio set, even though not staged inside a building. Fig. 5 shows a natural scene set. 100 I i MOTOGRAPHY 33 Studio Lighting. Artificial. Artificial lighting for studio scenes is most economically done with mercury-vapor lamps. These lamps are made of long glass tubes containing mercury. When glowing, they gi\e a green light, rather disagreeable to the eye at first, but very powerful in acting upon the sensitive photographic film. The light must be sufficient to impress the image upon the sensitive film in the short time allotted by the camera for each of the little pictures. This is a minimum requirement of fifty standard mercury-vapor lamps for a stage set measuring 14 feet wide, for satisfactory results Fig. 6. Indoor Studio Setting for Outdoor Scene, Showing Lamp Arrangement for Artificial Lighting in the finished pictures. Studio lamp plants vary from fifty to one hundred and fifty lamps, and vary in cost from $2,500 to J^10,000. As used in motion-picture studios, the mercury-vapor lamps are mounted in groups, usually six or more lamps per group, some of the lamps being hung from the ceiling of the studio for top lights and some beinff mounted in standing frames for side lights. The lighting arrangement will be clear from a study of Fig. 6. The studio is entirely without light other than the artificial light of the mercury-vapor lamps, which are arranged upon the ceiling and upon both sides of the scene set. In a studio of this kind, it is possible to 101 \ 34 THE MOTION PICTURE confine all scenes to the standard stage dimensions of the studio, the lamps being properly arranged and sufficient in number to light that standard stage area properly. Working with a studio of the type illustrated in Fig. 6 makes the producer entirely independent of the weather conditions for his indoor scenes. In Figs. 2 and 3, large windows are placed in the wall of the studio at the left, making possible photography by dayhght when the weather is favorable, the daylight being supplemented as desired by the artificial light. In Fig. 2, a bank of mercury-vapor lamps is suspended from the ceiling, and the side lights also are in position. In Fig. 3, a battery Fig. 7. Lubin Factory, Showing the Glass-Roof Studio of top and side lights are glowing, although the daylight window is visible at the left in the view. Daylight. There is a quahty in the best daylight picture which is lacking in the best picture made by artificial light. The artificial lighting as used commercially is sufficient to impress the image upon the photographic film, but it does not reproduce in all fidelity the strength and diffusion of daylight, nor the uniformity in intensity and direction throughout the whole scene which is obtained from daylight. Lighting a large stage artificially also involves a large expense. The daylight studio is of three types — the glass house, the turntable, and the yard. The c/las.s house ii/pe of studio is shown in external view in Fig. 7. That an auxiliary lighting plant is de- sirable is evidenced by the details of Figs. 2 and 3. 102 MOTOGRAPHY 35 A studio of the turntable type is shown in Fig, 8. The mov- able platform is turned to get the sunlight in the right direction. Pictures may be made with this platform from early morning until sunset, and the producer may have his hght from the desired direc- tion at all times. The exposure to rain and wind are the objection- able features of a studio of this type. It seems hardly natural for the draperies inside a house to be in motion, even in a motion picture. Unless an inside studio also is available, the producer is dependent upon the weather in more ways than sunlight alone. The yard studio is a matter of setting up the scenery in a fenced enclosure, as in Fig. 4. Where the indoor studio is limited in size, Fig. 8. The Vitagraph Roof Studio, Showing Turntable Construction the method of Fig. 4 may be adopted for scene sets which cannot be staged in the restricted space. One adjunct usually forming a part of an established yard studio is the tank. The possibility of staging a scene with even a hmited amount of water adds much to the producer's possibilities. Pictures Without Studios. A prominent film manufacturing company operated for years without a studio and without painted scene sets, releasing a reel each week. On several occasions, film manufacturing companies, whose studios and factories are located in the northern latitudes, have sent producing companies to the tropics in the winter, where many complete dramas have been pro- duced before the camera without studio and without artificial scenery. The beauty and attractiveness of a motion picture is enhanced by avoiding painted scenery and its artificial appearance whenever 103 36 THE MOTION PICTURE possible. No painted scenery can equal the detail and accuracy of the physical objects. Fig. 3 would be more pleasing had the camera and actors been carried to Spain for a natural scene setting adapted to the requirements of the story. It is the custom to stage indoor scenes in the studio with painted scenery; to stage street scenes outdoors in the streets, using the natural street scenes; and to stage rural scenes in the country. A studio set for a street scene may be made thoroughly acceptable by care in preparation of the scenery and by avoiding vegetation in the scenery. In a street scene of long duration, the studio setting is a decided advantage, since the passers-by do not have to be contended with. The selection of natural settings is a feature of his work by which one producer easily may excel another in the quahty of his product. The motion -picture camera has a "narrow angle" eye, permitting the use of a small scenic setting without including the whole country-side as a part of the view. On the contrary, by a change of lenses in the camera, just as much of the whole view as IS desired may be included, panoraming the camera if necessary to include still more. The adaptabihty of the setting to the story is the principal point to be borne in mind when selecting natural scene settings. Pictorial merit in the scene itself is of secondary importance, but still is a matter of much importance when the best of motion pictures are desired. In outdoor settings, whether wholly natural or wholly or partly staged with painted scenery, constant care must be taken to avoid incongruous features of the background from appearing in the pic- ture. A scene which by the story of the drama is set in the fastnesses of a moimtain range, far from any civilization, when staged in a ravine near the studio should not show a house gable in the remote distance. The scene set in Fig. 4, as viewed by the fixed camera which made the illustration, shows tree tops above the stone wall, yet the tree trunks do not appear through the arch of the wall. This would be an error if it were to appear so in the finished motion picture. The motion camera in the illustration is nearer to the scenic stone wall, thus by its different perspective and narrower lens angle placing the top of the wall higher in the sky and above the tree tops, so that the tree tops are not seen in the motion picture. 104 MOTOGRAPHY -37 Properties and Costumes. The articles or "stage properties" used by the actors, include furniture and all kinds and classes of house furnishings from parlor clock to cook stove for indoor house scenes set in the studio; desks and typewriters for office scenes; carriages for street scenes; and revolvers and black masks for the bandits in the mountains. To obtain the articles needed for the production of a reel of film each week is a task requiring one man's attention. Once used, such articles as are likely to be used again are stored in the "property room." Unless the property man is systematic by nature, the property room soon will look like a junk shop. Costumes aside from the ordinary street dress of the actors also will be found in the property room, including particularly uni- forms for policemen and messenger boys, caps and aprons for the parlor maids, and freak clothing for the comedian. The property man is the producer's assistant. Seamstresses, tailors, carpenters, and local storekeepers are in turn the assistants to the property man. Actors. The best source for obtaining actors is the dramatic employment agency. Experienced actors are desirable, even for the minor parts, for the producer as a rule has no time for training the amateur. The custom is to employ actors for a day at a time only, the standard price being five dollars per day. One day the pro- ducer may need three or four actors, the next day twenty. In pro- ducing a drama occupying the producer for a week, he may require the leading characters for four days of work, a few minor characters for two days (one day in the studio and one day in the field) and a dozen more actors may be needed for a single scene requiring, with all rehearsals, but an hour or two. Stock Companies. Some actors seem to have an inborn faculty for expressing thought without words, others cannot catch the trick. The producer quickly recognizes this pantomime ability in an actor employed by chance, and lists such an actor for service in the more important characters of his productions, even placing a few such actors upon a fixed weekly or monthly pay instead of employing them at the day rate with irregular service. The group of actors thus employed continuously is called a stock company and is supple- mented by as many more actors for a day or more as may be needed for any picture. To distinguish between the stock actor and the transient, the latter is called a swpe, an abbreviation for supernumerary. 105 38 THE MOTION PICTURE Starring an Actor. For general production of pictures, con- tinuous use of an actor in all pictures becomes objectionable to an audience. Most emphatically is this so when in two half-reel pic- tures the same actor takes part in the two reels The young wife who just fainted in her husband's arms at the bedside of her dead child appears on the same picture screen after a quarter-minute title as giddy sixteen flirting with half a dozen beaux. On the dramatic stage, such use of an actor is not objectionable, but motion pictures, from the fact that the scene sets are so realistic, lead the spectator to accept the actors also as real and thus add another to the burdens of the producer. On the other hand, an actor may be "starred" in motion pictures as upon the dramatic stage. His name in the picture title will in- troduce him to the audience, and when his name is seen again in a title the same actor will be expected. If "Sammy at Niagara Falls" is successful on Sammy's part, the spectator will be pleased to see another title reading, "Sammy at Saratoga," "Sammy Inherits a Fortune," "Sammy Captures a Burglar," or "Sammy's First Love Affair." Rehearsals. In the case of scenes set in the studio, it is most convenient to set the stage complete and to set the camera also in readiness. The rehearsal then is made in full dress upon the fully set stage, and when the scene is creditably performed the camera is started and the scene repeated. If the scene is difficult to repro- duce, two negatives should be taken. If any flaw in the action occurs, or if the producer thinks that some variation would improve the scene, the scene should be retaken, the two scenes then being viewed and the best selected when criticising the proof copy of the film. On a scene of one minute in duration, the cost of repeating for the second negative is only two dollars for negative film, the stage set and properties being of course already at hand and the actors al- ready rehearsed. In the case of scenes set in natural settings, many parts of the action of the leading characters may be rehearsed before going into the field. Such rehearsals will shorten the time required in the field, and as weather conditions sometimes change suddenly, the saving of time is well worth considering. In the street scenes where a citv or villajje street is used, the 106 SCENE FROM PHOTOPLAY, "THE TEMPTRESS" Courtesy of Independent Moving Pictures Co., New York THE CONTEMPLATED SUICIDE PREVENTED BY THE BURGLARS Scene from Photoplay, "A Good Turn" Courtesy of Lubin Manufacturing Company, Philadelphia MOTOGRAPHY 39 action required should be thoroughly understood by all actors in- volved, and completely rehearsed if of a nature to make rehearsals possible, Fig. 9. Any rehearsal in the street will gather a crowd of onlookers, and the longer the rehearsal the larger the crowd. Even the setting up of the motion-picture camera on its tripod is in itself an invitation for a crowd to gather around it, and some of them will persist in trying to get into the view. The passing policeman usually will help, but the scenes, if any, must be short on a busy street. City ordinances usually prohibit the making of "commercial" motion Fig. 9. An Indoor Eehearsal for an Outdoor Scene pictures in parks or boulevards. A bhnd camera, in a wagon which may be stopped at the curb unobtrusively, and two or three actors fully rehearsed, may "put on" a street scene completely and have it photographed and finished before passers-by realize what is being done, or even without their knowledge at all, even utilizing some of the street traffic as a part of the scene. Producing a Drama. To produce the drama, "A Midnight Cupid," the scrip of which has been given, the producer would classify his scenes into "studio" and "field" work, as follows: Studio Scenes: CM room, Scenes 2, 3, 5, 7, 26. Parlor, Scene 4. Cot- tage bedroom, Scenes 19, 21, 24. 107 40 THE MOTION PICTURE Field Scenes: First park set, Scene 1. Second park set, Scenes 6, 16. Store set, Scenes 8, 14, 17. Cottage set. Scenes 9, 10, 15, 18, 23, 25. Field set. Scenes 11, 12. Street set, Scenes 13, 20, 22. Reviewing these for characters, the four principal characters and three men for minor parts will make all field work with the addition of "children playing in extreme background" in Scene 14, and Scene 6, which recjuires the two servants from the studio scenes; the farmers cannot double for the servants because they appear together in Scene 26. Motion Scenes. Scene 4 rec|uires a bunch of troublesome actresses and a large expense for wages for a single scene; if possible, it should be made when the bunch of girls are in the studio in conjunction with the scenes of another drama. By working this Scene 4 into the routine of another production having a parlor scene with the same scene set and actresses, the expense will be reduced and the producer's time will be economized. Aside from Scene 4, all scenes should be made in continuous work. The studio being set for the club man's rooms. Scene 26 may be made first. This scene being made, the actress who played "woman aged 40" and the actor who played the "minister" is dis- missed. The two "well-dressed men" may be dismissed, or they may make up promptly for grocer and policeman if the producer desires them to double in the drama. Time is allowed for them to make up for the new parts while Scenes 2, 3, 5 and 7 are being en- acted before the camera with the same stage setting used for Scene 26. Studio work for the drama now will be completed by resetting the stage for the cottage bedroom. Scenes 19, 21, and 24, the actors required being only the three leading characters, CM, G, and GF. These three scenes may be made before Scene 26, or after return to the studio from the field work, according to the producer's con- venience. The producer now takes into the field the four major actors, a policeman, two servants, two farmers, the grocer, and children for Scene 14. Scene 6 is rehearsed and performed before the camera; the two actors taking the part of servants are then dismissed. Scene 16 follows Scene 6 without permitting the tramp to rise from his position on the bench, the action of the two scenes being substan- tially continuous, but the camera lens being capped for a foot of 108 i MOTOGRAPHY 41 the film to make a break in the negative between the two scenes when the negative is developed. With a slight change in camera stand, Scene 1 is produced, and the actor taking the part of the pohceman may be dismissed. Proceeding to the village where the natural scene settings have been selected or are known beforehand to exist, the outside of the village store is taken first, Scenes 8, 14, and 17 being produced in order. The children now may be dismissed. The street set may be made next, making Scenes 13, 20, and 22 in order. Next the cottage set, making in order Scenes 9, 10, 15, 18, 23, and 25. Then the field set for Scenes 11 and 12 completes the action scenes of the drama. The scenes have been made in this order: 4, 26, 2, 3, 5, 7, 19, 21, 24, 6, 16, 1, 8, 14, 17, 13, 20, 22, 9, 10, 15, IS, 23, 25, 11, 12. The titles are yet to produce. Revinv and Criticism. When the negatives have been developed, a print is made from each and all are spHced together in the order in which the scenes occur in the drama. The complete drama, in action scenes only, is projected for the criticism of the producer and others, including perhaps the author. The result of this criticism in some cases may be that the entire production is rejected, even the story being condemned as unsuitable for a motion-picture sub- ject, or the producer may be required to reproduce the entire drama or certain parts of it. Perhaps some actor is judged unsuited to his part and all scenes in which he has appeared must be retaken with another actor substituted. Padding. \Mien making each scene, the producer had before him a schedule for the length of each scene in the drama to produce the total length required. In the review and criticism, some scenes may be cut in length and others omitted for cause. If this reduces the total length of action scenes below the required amount, scenes may be substituted to fill out, or the remaining scenes may be left a little longer than their predetermined or required lengths. This is "padding" the film. As an example of what might be done at the risk of spoiling a good film picture, "A ^Midnight Cupid" might open with the village cottage scene setting, girl despondent talks to father, brings paper and pen, father writes, then show title the letter which the tramp reads in Scene 1. A scene of the tramp's troubles seeking food and expressing hunger may be inserted between Scenes 1 and 2. 108 42 THE MOTION PICTURE Between Scenes 7 and 8, scenes showing the club man en route to the country may be inserted, and between Scenes 25 and 26, scenes of all the characters en route might be added. Distinction may be drawn between a scene added to lengthen the film and a scene added for the purpose of strengthening the telling of the story, only the former being "padding." Rewriting. The scenes and their order being determined, the producer must correct the synopsis and perhaps other parts of the scrip to fit the completed drama if any correction is necessary. Particularly in the review and criticism is the matter of titles dis- cussed, and titles in correct and final form are determined. In the corrected synopsis, the length of each scene and of each title is noted. Titles. The titles are made by the producer or under his direc- tion and are given to the photographer to be done into film. The title is painted, printed, written, typewritten, or drawn, or made of movable letters arranged upon a support and removed after photographing to be rearranged for other titles. The size may be anything desired. The length of film for a title should be proportioned to the number of words in the title, being thus proportioned to the length of time which the spectator requires to read it. Two feet is enough for a single word, and a foot per word may be taken as a rule for titles longer than half a dozen words. A sign writer who personally prefers a full arm movement would paint the titles on a sheet probably 4^ by 6 feet. A sign writer who prefers to use a small brush and a WTist movement would work on cards probably 18 inches by 24 inches. In either case, black paint on a white background may be produced as such in the finished film picture, or it may be reversed by the photographer. A very satisfactory title is produced by setting up the words with printer's type and printing the title upon a printing press. In such a case, in order that a sharp photograph may be made, the original should be at least as large as 6 inches by 8 inches. \Miere movable letters are used for titles, it is necessary only for the producer to give to the photographer a written title, or a sketch of the word arrangement desired. For titles in the nature of messages, letters, telegrams, etc., the messages may be printed with printer's script type and handed over to the photographer. Such a title probably would not be larger than 3 inches by 4 inches. 110 MOTOGRAPHY 43 Written messages may be prepared just as the picture screen is to show them, written by hand with black ink upon white paper. The handwriting of the message should be consistent with the character of the actor writing it, and should show creases if the message has been folded in the motion scenes of the play. For tele- grams, use the regulation telegraph blank. Use a "send" blank for messages to be sent and a "received" blank for messages received. They may be written either by hand or typewriter. Borders for titles or trademarks for titles may be incorporated into the titles by drawing or printing the title upon sheets which have been printed previously with the border or trademark. A "reversed title" is a name given to titles having the letters show in white upon a dark picture screen. This effect is obtained directly by painting with wiiite upon a black background, or by arranging movable white letters upon a black table, but it may be produced from black letters upon a white ground by an additional process in photographing. It is not suitable of course for messages. A reversed title is much more easily read and is much more accept- able to the audience than a title which has black letters upon a w'hite ground. The reversed title is further improved by tinting. Final Criticism. The titles being completed, and added or changed scenes having been reproduced, the proof for the first criticism has each scene cut to its prescribed length and proofs of the titles are cut to their prescribed length and inserted among the motion scenes in the order required by the revised synopsis. Thus, there is produced a final proof picture of the complete film as it is to be released to the public. The final proof is projected before the producer and critics and if approved it is turned over to the photographer as "copy." The photographer cuts his negative into lengths, both motion scenes and titles, splicing them together to reproduce a complete continuous negative of the approved "copy." Whether the film be drama, comedy, travel, chase, or trick, the procedure of motion-scene production, first criticism, rewriting scrip, making titles, final proof, and approval of copy is on final criticism in substance the same. At this point, the film picture passes out of the hands of the producer and into the hands of the salesman, or advertising mana- ger of the producing company. Ill 44 THE MOTION PICTURE THE SALESMAN The salesman of the film manufacturing company, or the adver- tising manager, as his title usually reads, has as his task the disposi- tion of as many copies of the finished picture (as many photographic prints from the negative) as his opportunity and ability can effect. Branches of the Film Industry. The customer of the film manu- facturer is the film exchange manager, or renter, whose customer in turn is the film exhibitor. The film industry is definitely separated into three branches: manufacturer, renter, and exhibitor. The renter owns the picture films. He buys from the manufacturer for cash and rents the films to the owners of picture theaters for exhibition. The exliibitor owns no films, merely renting them for a day or a week from the renter; the manufacturer owns no positive picture films, merely printing from his film negatives as many copies of each picture as can be disposed of immediately to his customers, the film renters. Selling Methods. General publicity is obtained among the renters and exhibitors by advertising in the motion-picture magazines. In the magazine advertisements, the general excellence of the mg-nu- facturer's film pictures is told, and the current film pictures just produced or about to be produced are announced by title with a few descriptive words and illustrations. , Lectures. The magazine advertising is supplemented by lec- tures or short stories of the film pictures. The lectures derive their name from the original purpose, which was to provide a talk to accompany the picture, explaining the story of the picture as the action progressed on the screen. While the original purpose of lec- tures is almost extinct, their advertising value remains and they are used by manufacturers in large quantities. Each film picture has its lecture and these are printed either separately, or in a little pamphlet covering the manufacturer's output of film pictures for the week or for two weeks. The lectures are written by the salesman or his assistants, using the corrected synopsis or scrip of the story as a guide and keeping in mind at all times the film as actually produced. At least the motion scenes of the picture should be produced and reviewed by the critics before the film is advertised for release and before the 112 MOTOGRAPHY 45 lecture is written. The writer of the lecture, having sat at the pro- jection of the proofs for the preUminary review, will be further guided in writing the lecture by his recollection of the strongest scenes of the production. The lecture is illustrated by views of the film taken from the scenes either by clipping a small image from a copy of the proof film or by photographing the scene with a hand camera upon a larger scale while the picture is being produced. In either case, the engraver is able to produce printing blocks of the desired size for the lecture. Lectures are mailed in advance of the release date of the film. They are sent to the magazine publishers that they may be printed in the magazines either in full or in part, for additional advertising value to the manufacturer. They are sent to the film exchanges that the renters may know what pictures are promised for the ad- vance dates. They are sent to the exhibitors that the exhibitors may be impressed by the lecture that the film is especially suited to their particular audiences and that the exhibitors may ask the renters for the picture and the renter thus be obliged to buy the film from the manufacturer. Release Dates. The routine of manufacturing and selling motion- picture films can be compared very closely with the routine of print- ing and selling a newspaper or magazine. The amusement business is established upon a weekly basis. In theatrical circles, a year is spoken of as fifty-two weeks, and a day one-seventh of a week. The big theaters change their bills at the end of the week, and the vaudeville programs are changed weekly Similarly, in the motion-picture theater, the program is made upon a weekly basis, the film renter makes his schedules upon a weekly basis, and it best suits his convenience to receive his films from the manufacturers upon a weekly schedule. As the business man gets his newspaper every morning, so the prominent "daily change" motion-picture theater gets its new film every morning from the renter, who, in turn, gets films every morning from the various manu- facturers. Orders are placed by the renter on a basis of weekly deliveries, that his schedule may run smoothly. Monday morning brings a reel from manufacture^ A, Tuesday a reel from B, Wednes- day a reel from C, Thursday another reel from A, Friday another reel from B, and Saturday a reel each from D and E. These de- ns 46 THE MOTION PICTURE liveries are repeated weekly, giving a constant schedule of seven reels per week, combining the product of several manufacturers. In view of the deliveries required by his customer, the renter, the manufacturer is obliged to issue his pictures as regularly and as punctually as a publisher issues his magazine to the newsdealer. Each film manufacturer, therefore, establishes one or more release davs for each week, according to the number of reels of film which he will manufacture per week, and advertises that a full reel of film will be sold or "released" upon each of his release days. Advance Shipments. It has been found convenient to release a picture in all parts of the United States upon its release date, and this is accomplished by advance shipments to discount the time in transit, and by shipments further advanced to discount the likely delays in transit. A New York manufacturer will ship his pictures to San Francisco customers seven days in advance of his release date; to Denver or New Orleans customers five days in advance of his release date; to his Chicago and St. Louis customers three days in ad- vance; to Philadelphia and Boston customers two days in advance; and will deliver by messenger to New York customers on the evening before the date of release. In the case of the distant shipments, the films should arrive two or three days ahead of the release date, but the renter is honor bound to issue them to the exhibitor only on and after the release date. In case it comes to the attention of any manufacturer that any renter is violating the release date, the advance shipment for discounting delays in transit will be with- held. Factory Schedule. A safe schedule for insuring the release of the picture film to the renter promptly upon the release date carries the beginning of the work of making the film back to a date many weeks before release. A picture to.be released on May 6, if manu- factured in New York, must be shipped to the San Francisco and Los Angeles customers a week in advance, on April 29. The photog- rapher must have time in advance of this to enable him to print the pictures from the negative, so the approved "copy" of the film must be delivered to the photographer on April 22, two weeks in advance of release date, that he may fit his negative to the "copy" and begin printing in time for the west coast shipment. Inasmuch as the final criticism may require changes before the "copy" is approved, the 114 MOTOGRAPHY 47 projection of the picture for final criticism is set for April 15, three weeks in advance of release date. Between projection of the motion scenes for preliminary criticism and projection for final criticism, one week is not sufficient for remaking condemned scenes, produc- ing padding scenes, rewriting the scrip and maldng the titles. Par- ticularly in view of the possibility that the entire picture may be rejected, an interval of three weeks is none too short between pre- liminary review and final review in the ordinary progress of the factory. The date for preliminary criticism is set for six weeks in advance of release, or March 25 for preliminary criticism for the May 6 release. For ordinary productions, give the producer a latitude of two weeks for his motion scenes, and two weeks preced- ing for preparation of his scenery and properties, taking the delivery of the scrip to the producer back to ten weeks in advance of release date, or February 25, for the release of May 6. Still back of this date is the writing, criticism, and acceptance of the original scrip. Some pictures, particularly trick pictures, may recjuire many weeks for the production of the motion scenes. In contrast with this is the story told of an eastern factory, that an actor in the noon hour suggested to the producer a thought for a comedy, that the producer dropped the work in hand and had the first scene of the new comedy on at two o'clock the same after- noon, and scenes were completed for a fidl comedy reel the follow- ing day. In contrast also is the method of a producer who habitually worked without scrip or scenario, producing only his own creations, direct from brain to film. Sales Contracts. The usual order accepted by the manufac- turer from the renter is an order for a predetermined number of reels per week — usually one copy of each picture produced by the factory. Such an order gives the manufacturer advance knowl- edge of the quantity of his output and it is by such orders only that a manufacturer is enabled to work upon so close a schedule as the one cited — giving but two weeks between the final approval of the "copy" of the picture to the release date. If it becomes necessary for the salesman to exhibit an advance copy of the finished picture as a means for getting orders for the films, several additional weeks must be inserted in the schedule between the final approval of the "copy" and the date of the release of the film. 115 48 THE MOTION PICTURE Title Posters. To advertise his program to the passers-by, the theater manager— or "exhibitor," as he is known in the trade — displays the titles of his pictures in front of his entrance. The salesman for the film manufacturer provides for attractive posters for the films released, either by furnishing them to the exhibitor directly through the film exchange to whom the salesman sells the film, or by providing necessary information to title poster com- panies to enable them to offer attractive title posters to the exliibitor. REPRODUCTION THE PHOTOQRAPHER If the factory is to be considered as distinct from the studio, and from the o^ce, then the office is the department of the sales- man, the studio is the department of the producer, and the factory is the department of the photographer. "Factory superintendent" perhaps would be a suitable title for this photographer, for he does but little of the photographic work with his own hands. The di- visions of his factory taken in the order in which they become useful in the making of a picture film, are as follows : Divisions of the Photographic Factory. The raw sensitive film is purchased cut to size and packed in tin cans. A fireproof iron safe or a fireproof vault for film storage holds the film until needed. From the vault, it is taken to the perforating room, where holes are punched in the edges Thence the negative film- goes to the camera man, who is the photographer's employe working under orders of the producer. From the camera man the exposed film goes to the developing room, where it is developed into a negative. Then titles are made. Scenes and titles being finally approved and spliced up according to "copy," the film negative goes to the printing room and supplies of positive film also go from the perforating room to the printing room, where the positive film is printed from the negative. The negative, after all prints are made, goes to the film storage room permanently. The printed positive film goes from the print- ing room to the developing room which developed the negative, then to the washing room, then to the drying room, and when dry to the inspection and splicing room and again to the fireproof storage vault until the day for packing and shipment. In brief, the divisions 116 MOTOGRAPHY 49 of the photographer's factory are film storage, perforating, camera, developing, title making, printing, washing, drying, inspecting, and shipping. The strip film is bought ready for perforating. The total task of the photographer — or "factory superintend- ent" or whatsoever title he may bear in various film manufacturing plants — is to produce a creditable photographic film picture when the producer has enacted the scenes and has written the titles. This task requires the photographer to have his assistant, the camera man, present when the producer, enacts a scene, and leaves the responsibility upon the photographer — through his assistant, the camera man — for the proper photographic record of the scene upon the negative film of the camera. The division of responsibility at tliis point is logical. If a negative is lost because the camera man used the wrong stop in the lens, the failure is photographic in nature, and the photographer is to blame because of the incompetency of his assistant. From this point to the delivery of the film for shipment, the processes are wholly photographic. The photographer assigns his camera men to the producer as demanded, providing them with negative film, and delivers proof prints to the producer for criticism. From approved proofs and picture "copy," the photographer prints finished film pictures as requested, and delivers them by shipping them under the salesman's orders. Raw Film. Compositio7i. The sensitive film before use in the camera consists of a long narrow strip of celluloid coated with a gelatine photographic emulsion. Its manufacture is distinctly in two parts, the making of the celluloid strip and the making of the sensitive emulsion and coating the celluloid strip with the emulsion. Neither the making of the celluloid nor the coating should be at- tempted except by skilled workmen in a thoroughly equipped factory. Manufacture. Celluloid is made from pyroxylin and camphor, the pyroxyUn or guncotton being made from raw cotton by treat- ing it with nitric and sulphuric acids. Sulphuric and nitric acids are mixed in practically equal quantities, the raw cotton is dipped until saturated but not allowed to dissolve, then is thoroughly washed and dried. By this process the cotton has been transformed into guncotton, an article very explosive' in nature, but not different in appearance from the original raw cotton. The camphor is dis- solved in alcohol, making a saturated solution. 117 50 THE MOTION PICTURE A layer of drj' pyroxylin is placed in a tank and about one- half the quantity of camphor solution is sprinkled over it, then pjToxylin, then camphor, and so on. The pyroxylin dissolves in the camphor solution and celluloid is formed in lumps which sink to the bottom of the tank. The lumps of celluloid are worked be- tween rollers, cold and hot, and pressed in hydraulic presses and dried. The celluloid stock is worked into thin strips for motion-pic- ture work, the strips being 1/200 of an inch in thickness. The width and length may be anything desired, say 22 inches wide by 200 feet long. Coating. The emulsion for coating the film is of two kinds, slow for prints and fast for negatives, a bromide emulsion for the slow and a nitrate emulsion for the fast. The emulsion, made as for photographic dry plates or hand-camera films, is placed in a coating macliine having an emulsion hopper and a sUt to feed the emulsion upon the celluloid. The 22-mch strip of celluloid is passed at a uniform speed through the machine and under the emulsion slit, receiving a uniform coating as the emulsion flows out upon it. The wide strip of film is dried and taken through a cutting machine which splits it into strips If inches wide and 200 feet long. The narrow strips are rolled up and packed in round flat tin cans, sealed vvith adhesive tape, one strip, or 200 feet of film, in each can. It is now ready for delivery to the motion-picture manufacturer N cM-hiflcnnmahle. The celluloid base of the motion-picture film is highly inflammable, although not explosive in that it will not take fire unless a flame is applied to it or it is heated to a very high temperature to start combustion. The heat of the projecting arc concentrated upon the film in the film window of the projecting ma- chine is sufficient to ignite it. ^^^len ignited, it bums rapidly Many experiments have been made either to discover a sub- stitute for the inflammable celluloid for use in motion-picture work, or to discover some modification of the process ii making celluloid which would render it less combustible. By adding amyl silicate or methyl silicate to the vat in which the pyroxylin and camphor are combined, a sufficient quantity of silica may be added to the celluloid to reduce its inflammability so that it will burn very slowly, if at all. The addition of calcium chloride to the celluloid com- 118 MOTOGRAPHY 51 pound also produces a similar result. The finished mass of new celluloid while still soft may be treated with stannous chloride, rendering it less easily combustible. A non-inflammable product made by combining camphor with an acetate cellulose instead of with a nitrate cellulose, or pyroxy- lin, has been used widely as a substitute for the inflammable celluloid strip for motion films. This is the "N. I." commercial film, and gives satisfactory senice for a short life. Its objectionable point is that with age and the heat of the projecting arc it shrinks to some extent and becomes some- what brittle. Storage of Film. The greatest care must be taken in selecting a place for the storage of the raw film, as also for the storage of the finished pictures before shipment, and for the storage of the film negatives, the most valuable of all, par- ticularly during the period between pre- liminary approval and the release of the picture. The storage room must be so situated and constructed that the film will be kept safe from flames and will be kept cool. \Mien warm, celluloid gives off ex- plosive gases rapidly. A vent pipe for such gases may be formed by a pipe of small size leading to the open air and guarded with steel wool or gauze to pre- vent backfiring. Perforation of Film. The standard perforation is four holes per picture, or rather four pairs of holes per picture. Each hole is approximately j\ inch by /^ inch, spaced along the edges of the strip of film at a distance of -^ inch apart, maldng four holes on each edge for each f-inch motion- picture image. The photographic images being 1 inch wide, and the film strip If inch, the pictures being also in the middle of the Fig. 10. Specimen of Positive Film 119 52 THE MOTION PICTURE strip, there remains a margin of ^\ inch on each side of the strip for the feed holes. The perforations are placed in this margin, not centrally in the margin, but against the side of the image to leave as wide an edge of celluloid outside of the perforations as possible to strengthen them against break- ing out to the edge. In the illustration of a specimen of picture film, Figs. 10 and 11, the perforations seem to encroach upon the photographic images. Indeed, in the pro- jected picture upon the screen, the edges of the perforations sometimes are seen at the side of the picture because of a lack of proper centering of the film in the project- ing machine. Shape. The three shapes of perfora- tion commonly used are known as round, square, and barrel. They are illustrated in Fig. 12. The square and barrel holes seem to give longer life to the film than the hole having the round form. The shape of the tooth in the projecting machine which enters the film perforation and by which the film is pulled through the projecting machine should determine the shape of the hole. The tooth most commonly met has a flat pulling face, and this pulls best against the flat surface edge of the hole offered by the shape of the square or barrel perforation. Spacing. The sprocket method of feed- ing the film allows some latitude in dis- tance of perforations, and thus cares for slight inaccuracies in the perforating ma- chines, and for the variation due to shrink- Fig. 11. Negative Film. Motion age of the film with age or with its treat- ;^th'"bTuc^s}:i°f'any'wh.tment in the processes of development and drying after leaving the perforator. The apron. color:j.) (Film shows reverse 120 MOTOGRAPHY 53 spacing in the perforating machine should be -^^ inch per hole, and it should be uniform. Careful experiment has shown that the films whose sprocket holes wear best are those whose sprocket holes are most uniformly punched, regardless of whether they have main- tained their original distances or have been subjected to change by development processes or by age. If the holes are not uniform, one hole edge will get more than its share of pull from the sprocket teeth, and that hole will break out, its neighbors then getting an excess strain and breaking in turn until the film must be cut and spliced. The splice in passing through the film gate places an abnor- mal strain upon the edges of the perforations in advance of it and Fig. 12. Shapes of Film Perforations which have to pull it through the gate. Thus the trouble started by uneven punching is cumulative and shortens the fife of the film. Perforating Machines. Self-feeding or automatic punch presses for punching small blanks out of sheet metal may be seen in large machine shops. When provided with proper punches and dies they become suitable for perforating motion-picture film. When the punches are of the reciprocating type, a group of eight punches work vertically above a plate having holes to receive the punches and having guides for the unperforated strip of film. Associated with the punches are two "pilots," tapered fingers, which come down with the punches and pass into the last holes of the film strip, that the distance from the last holes to the new holes ubout to be punched may be exact. .\n intermittent feed device, similar to that of the camera or projecting machine, worlvs into the holes of the perforated end of the film and pulls it forward one picture length between the strokes of the punch. Punches of this type may be operated at speeds of 500 to 1,000 feet of film per hour. Only one strip at a time is punched. In the case of rotary punches, two drums are built, one of which 121 54 THE MOTION PICTURE has in its face recesses corresponding to the holes of the finished film and the other of which has teeth to match the recesses of the first drum. The teeth are of such length that they reach to the edge of the recesses of the companion drum but do not enter. The drums are revolved in unison and the film strip is passed between them. Revolving brushes keep the punched-out pieces from follow- ing around the drums and entering again. Rotary punches are of high capacity, being able to perforate film at a rate of 5,000 feet or more per hour. They are more likely to get out of accurate adjust- ment than the reciprocating punch, and are more difficult to sharpen when dulled by service. Perforating Room. The perforating room is a darkroom, photographically dark while the perforating machines are working the film. It is only when all film is safely shut in the tin cans that the white light may be turned on or the door opened. It has a "light- trap" entrance, or in the wall is built a turntable with four wings, like the revolving doors of a store or office building, encased light tight, with a window into the turntable inside the darkroom and another outside. By this turntable, a few cans of punched film may be passed out on demand without waiting for the punching machines to finish their strips of film to permit the door to be opened. Camera Man. Only a photographer who has demonstrated his ability to make good negatives with the fixed camera under varying conditions should attempt to qualify for the position of camera man with a motion-picture factory. Upon the camera man, as representative of the factory photographer, rests the responsi- bility for getting a good negative of the scene enacted by the pro- ducer. A photographer who can make a good fixed camera negative of the scene setting can acquire easily the necessary skill in turning the camera crank at a uniform rate of speed, and then is fully com- petent to make a thousand motion-picture images of the same scene while the action of the scene is taking place. Camera. The professional motion-picture camera should have the following features: A well-halanced intermittent movemetU, turning smoothly and uniformly in all crank positions; an adjustable shidtcr, adjustable to give a variable ratio between the "open time" and "closed time" of the film window for each revolution of the shutter, that is, for each picture made upon the film strip; two or 128 MOTOGRAPHY 55 more lenses fitting into the same mount or flange ring, the lenses being of different focal length for changing the angle of the view or the size of the images in the film window and for decreasing or increasing the depth of the field for action in the scene; focusing mount for the lenses, either having each of the lenses in its own focusing mount or preferably having a single focusing mount into which any one of the different lenses may be inserted; a sliding lens hoard, equivalent to the rising and falling front of the fixed camera; detachable light- tight film boxes, equivalent to the dark slides of the fixed camera preferably of such construction that the film boxes may be inter- changed without opening the mechanism compartment of the camera; a trick picture crank; a reversing crank or a reversing tripod socket; a detachable main crank or preferably a, folding main crank; a level; a finder for panoraming; a finder for focusing window, for focusing without opening the camera; an indicator showing the amount of film used and unused at any instant; a speed indicator showing at any instant the speed (in pictures per second) at which the camera is being turned; difilm marker which may be operated from the outside of the camera to mark upon the film an indication of the position of the film window upon the film; a stiff tripod with panoram head; a carrying case. In addition to providing for the panoraming move- ment or horizontal swinging movement of the camera upon the tripod, the tripod head sometimes provides for a rocking movement of the camera vertically. In size, motion-picture cameras vary greatly, even when built to carry the standard size film, If inches wide, and the standard quantity of a 200-foot reel. The comparative size of camera and man is seen in several of the figures. The Urban camera is about 18 by 18 by 6 inches. Others have been made showing a front 6 by 10 and a depth of 14 inches. Some cameras, as the Urban, carry the film boxes inside the camera case, while others attach the film boxes to the outside of the case, thus making the size of the camera case alone seem deceptive when given in figures. The weight of a camera will vary from eight to twenty pounds. Film Movement. Successful cameras have been built by con- structing a light-tight box for the motion head of a projecting machine. Such an arrangement fills all requirements although it may make a bulky camera. The limitations in building a film shift for a camera 123 56 THE MOTION PICTURE are less rigid than those placed upon the projecting machine, because of the shorter period of rest. In the projecting machine, the film must be at rest for at least eighty per cent of the time, and must be shifted in the remaining twenty per cent of the picture interval. In the camera, the intermittent mechanism may be such as to use forty per cent of the picture interval in movement if desired. The margin of safety for a good picture in a camera is of greater importance than in a projecting machine. If the projecting machine is out of order, it is known immediately by the result upon the screen, and the machine is adjusted. If the camera is in any way out of order, it is known only when the films are developed at the end of the day's work, with the result that the day's work must be done over by the producer. The film in the camera must be motionless during the interval of exposure to the lens. The claw type of intermittent movement seems well adapted to this end, since the claws may advance into the perforations, seize and pull down the film and retire from the perforations entirely, leaving the film entirely out of contact with the film shifting mechanism and, therefore, to the greatest degree unaffected by the driving devices which, were there any actual con- tact between the driving devices and film, might cause a slight move- ment. During the period of rest of the film the claws return to the position from which they advance into the perforations to give the film its next step, and during this interval the exposure of the film to the lens is made. That the claw-shift mechanism subjects the film to greater wear than the sprocket movement becomes of less import- ance in the camera than in the projecting machine, since the film is run through the camera but once. In addition to the Edison camera, using the sprocket with perforated film strip, and the Urban, Gaumont, and many others using the claw movement with perforated film strip, all of which use intermittent movement of the film, there are two other classes of cameras — those which do not use the intermittent film movement and those which do not use the perforated film. The object in the use of cameras avoiding the perforated film and the intermittent movement usually is found in an intent to avoid patents bearing upon those features. The Bianchi camera, used by Columbia licensees, makes pictures upon a continuously moving film. The 124 I MOTOGRAPHY 57 Hamacek camera uses an unperforated film, the film being perforated after development of the negative. Loading Film Holders. Each film holder consists of a black box of thin wood with door and spindle. One side of the box opens as a door, either hinged or entirely removable. The spindle or hub passes through both sides of the box, back and door, turning in journal boxes carried by the back and the door, and usually being removable from the box merely by hfting out when the door is open. The hub has a clip or slot for attaching the end of the film, so that the film may be wound upon the hub when the hub is turned. Upon the end of the hub — usually upon that end which projects through the back of the film holder, but in the case of the removable hub the two ends should be alike — is a key way whereby the film move- ment of the camera may engage the hub and turn it to wind up the film. The key is a slot or a pair of holes for pins, and in the camera at the position for the take-up film holder is a key corresponding to the key way. The negative film will be supplied from the factory storage vault in rolls of 200 feet, perforated, rolled with an open center a Httle larger than the hub of the film box of the camera, and packed in a round, flat tin can sealed with adhesive tape. In loading an empty film holder, it is necessary only to open the door of the holder, open the tin box (in the darkroom), drop the roll of film over the spindle, pass the end of the film through the slot of the holder, and close the holder. In reloading a film holder containing exposed film, the proc- esses are different, depending upon whether the holder has a remov- able spindle or hub, and whether an extra hub is at hand for reloading the removable hub type of box. \Mien the removable hub type of film holder is used, the factory should provide an extra hub with each roll of negative film, packing it in the tin box in the hollow center of the film roll. To reload, the camera man opens (in the darkroom) both tin film box and camera film holder, removes the new film from the box, lifts the exposed film from the camera film box to the tin box without renioving the hub, upon which the film is wound tightly, and seals the tin box with the adhesive tape. He then fits the new hub to the film holder, drops the new roll of film over it, threads the end of the film through the slot, and closes the fihn holder. 125 58 THE MOTION PICTURE In reloading the film holder in which the hub is not removable, the camera man must have a film winder, winding the film out of the holder, then changing the new roll of film from the tin box to the film holder, and then the exposed film from the winder to the tin box. Exposed and Unexposed Films. Safeguards are necessary to avoid the accidental exposure of the same film twice in the camera, either from the mistake of putting an exposed film holder back in the camera or from the mistake of reloading an exposed film from its tin box back into the film holder and thence to the camera. In short, there should be some signal to indicate that the roll of film has been exposed, similar to the turning of the dark slide of a plate- holder. The outside end of an unexposed roll should have its corners clipped to faciUtate threading through the camera when loading. The inner end should be left square. A roll with the outer end square, therefore, is an exposed roll. WThen the film holder is loaded, the leading end of the film is threaded through the slot of the holder, and projects to be pulled out and threaded up in the camera. When the roll is exposed, it is wound up completely into the take-up holder, so that the end of the film does not extend from the exposed holder. In a camera having holders with removable spindles or hubs, the exposed roll of film will have a hub in its center upon which the film is tightly wound. The unexposed film will have the hub in the tin box, perhaps, but the film will not be tight upon it. In a camera without removable spindles, a roll of film which has been removed by the camera man in reloading, probably will have a different size of center hole from the roll received from the factory film storage room. Tin boxes containing unexposed negative film in the factory storage room should be wrapped in paper and the wrapper pasted shut so that the paper must be torn to get it off. WTien reloading film holders, the camera man does not wrap the tin cans of exposed film, hence the only fresh film the camera man has is the film in the wrapped boxes and in the film holders with the leading end stick- ing out. In addition to all other precautions, the exposed film should be 126 MOTOGRAPHY 59 sent in to the factory as soon as exposed, but even then the factory may send back an exposed roll to the camera man, and danger sig- nals should be watched for. For studio work and field work close to the factory, film holders may be loaded in the factory darkroom. \Miere the camera man is in a distant city or still worse in the country, it may be necessary to transfer film from tin cans to camera film holders when no dark- room is available. A bedroom closet will serve if an assistant out- side will hang clothing or bed clothing over the cracks of the door until the camera man inside can see no hght, KneeUng on the floor at the bedside with the hands (and films and boxes) under the covers, either at night or with shades drawn and a bed cover hung over the window, the camera man may work by touch. Have an empty tin can and as a first operation transfer the film to the can and as a second operation transfer the film from a new can to the film holder. In the field, if the emergency arise, take off the coat and shove the arms through the sleeves the wrong way, changing the film inside the coat. An assistant supplies the film and boxes to the hands in- side the coat, and muffles it further by any available clothing. Get in the deepest shadow available. For all these emergency methods it may be borne in mind that the roll of film is largely self-protecting. On the sides of the roll, the Hght must penetrate 3/16 inch before reaching the latent images, the inner layers are hght-struck by the acts of loading the camera and they serve to protect the following layers, while on the outer layers there may be left several layers of unused film for protection if the emergency reloading is known in advance. Loading the Camera. The loading of the camera is an opera- tion designed for daylight work. It is no more difficult than thread- ing a film through a projecting machine. The full take-up film holder is removed. The empty film holder is taken from the feed position and fastened securely in the take-up position, the hub being connected with the mechanism of the camera, and the handle given a few turns to ascertain that the hub is turning properly to take up the exposed film. A loaded filmholder then is placed in the feed position and the end of the film pulled out to reach the feed mechanism. A brush should be attached to the inside of the camera door by a spring clip, and the inside of the camera, particularly the film window, 127 60 THE MOTION PICTURE should be brushed carefully to remove minute particles of celluloid or other dust particles left by the previous roll of film in passing through the machine. The new film then is passed through the upper steady feed, through the intermittent feed, and through the lower steady feed, to the take-up film holder, passed through the slot of the holder and attached to the take-up hub. The take-up holder is closed, and the handle is given a turn to make sure that the film is feeding properly and that the take-up holder is working prop- erly. The camera ease then is closed and the handle is turned once or twice as required to wind past the film window that length of film be- tween the feed film box and the film window which has been light-struck by exposure during the loading of the camera. In Fig. 13 is shown the Urban camera, with panoraming and ele- vating or rocking tripod head. The door at the left on the side gives access to the film holders and feeds for reloading the camera; the re- movable panel in front gives access to the intermittent mechanism. Fig. 14 shows the Gaumont camera, open. In this camera the upper and lower constant feeds are taken from the same sprocket, the intermittent feed mechanism being enclosed in a dust-proof box at the front of the camera. The feed and take-up reels are external to the camera body and have a very large capacity, 500 feet. Camera Man's Duties. Taking the Picture. To set up his camera when instructed by the producer, to include the scene pointed out by the producer, to begin turning and to stop turning when told by the producer, to keep his camera in adjustment, to keep an ample supply of film fotr the producer's requirements, and to turn over to the factory a correctly exposed roll of film having upon it a record 128 Fig. 13. Urban Camera MOTOGRAPHY 61 of the producer's scene from the word ''start" to the word "stop." Turning Crank. At the top of the illustration of the Urban camera is a round window in which a finger moves over a scale marked 10-12-14-16. When the handle is turned, this hand in- dicates the number of pictures per second which are being taken. The usual speed is fourteen pictures per second. Turning the crank at a uniform speed of fourteen pictures per second, without varia- tion in the speed and without shaking the camera upon its tripod, Fig. 14. Gaumont Camera can be done only after much practice. Variations are liable to occur in every turn, the inexperienced camera man turning faster as the handle comes down and not so fast as it is passing backward at its lowest position. They are liable to occur also by steady increase or decrease of speed, starting a scene at fourteen and finishing it at the rate of ten or eighteen pictures per second. When the actors are playing their parts in the scene, the producer is prompting them and the action becomes interesting or exciting, the new camera 129 62 THE MOTION PICTURE man is liable to become interested or excited also and either turn the crank so fast that his negative is spoiled or forget to turn it at all. Practice may be had by turning the camera crank without film. The length of exposure is dependent upon the speed of the crank. If the crank is turned faster as it comes down, the exposure will be shorter for the picture made then, and in the negative every fifth or sixth or eighth picture will be under-exposed as compared with the remainder of the negative. Such a negative cannot be used because a print from it would show similar variations and the result for the audience viewing the projected picture would be disagreeable. The crank must be turned without shaking the camera. If the operator throws liis weight upon the crank in any part of the turn, the tripod will yield slightly and change the view in the film window by sliifting it slightly up or down or sideways. This shift- ing will occur periodically with each turn of the crank and the result is a strange waving or surging effect in the projected picture. To turn a crank uniformly in all parts of its revolution, the elbow may be placed in hne with the center of the crank shaft and the crank turned with a movement of the forearm only, keeping the elbow still. In this way, the operator's weight is not thrown upon the crank and a steady rate is obtained. The beginner must keep his eye on the speed gauge until turn- ing becomes automatic. If there is no speed gauge, the best plan is to count while turning, and not to look at all at the action in the scene. Cameras have been built to give three, four, five, six, or eight pictures for one turn of the crank. Four, six, and eight are in com- mon use. The number of pictures, not the number of turns of the crank, is the end desired, and this means different crank speeds for different cameras. With eight pictures per turn — the speed most commonly met in modern professional cameras — fourteen pictures per second are obtained by turning the crank at the rate of 105 turns per minute; at six pictures per turn the crank speed required is 140 turns per minute. Many watches tick five ticks per second, 300 ticks per minute. Get a watch ticking 300 per minute and learn to count one-two-three, one-two-three, one-two-three, just as fast as the watch ticks, turning the crank one turn for every one- two-three, and the crank speed will be one hundred turns per min- 130 MOTOGRAPHY 63 ute, which is near the proper speed for an eight-picture camera. Count one-two, one-two, one-two, for the ticks of the watch and turn the crank of a six-picture camera one turn for each one-two. Useful practice may be had by turning the crank and holding the watch to the ear, a plan feasible even when actually taking pictures in the field. The greatest precautions must be taken by the new camera man to prevent the action of the scene taking his atten- tion from the crank. When the trick handle is used, it is to be turned at the same speed as the main handle, as though the full number of pictures were being taken. To secure the best results with the panoram handle, it should be operated by an assistant, but with practice passable results may be obtained by one operator, turning the picture crank with one hand while he turns the panoram handle at a different rate of speed with the other hand. Setting up Camera. The camera must be rigid upon its tripod, and it must be level. A level may be built into the camera case, or a small pocket level placed upon the top of the camera will serve, the level being tried both crosswise and lengthwise of the top of the camera. To "find" the view properly it may be necessary to tip the camera front up, but only ludicrous results will be obtained when the camera is not level crosswise. In the absence of a level, step back a few feet from the camera and "sight" it against the horizon line or some neighboring building. It is almost the uni- versal rule in making pictures of dramatic action with natural set- tings to set the camera upon a portable platform probably 4 feet high, thus bringing the lens of the camera above the heads of the actors and of passers-by. This elevation also enables the camera man to arrange his image with the horizon line above the top line of the picture and thus cut out any signboards, fences, and houses of the extreme background. Lens Length. The standard length for moving picture lenses is 3 inches. This gives an angle of view of about twenty degrees; a 2-inch lens gives an angle of about thirty degrees. The camera must include in its film window as much of the scene as the pro- ducer desires, and the producer must know, particularly in a natural setting, just where the limit lines of his scene are located, that he 131 64 THE MOTION PICTURE may keep his actors in the film window when they are supposed to be in the scene. ^More of the immediate foreground may be in- cluded in the film window image by moving the camera stand back, but where this cannot be done a similar result may be had by sub- stituting the 2-inch lens for the regular 3-inch lens. \Mien too much of the foreground is included, the camera may be moved forward or a 4-inch lens may be substituted. The camera man whose camera has but one lens will find himself at his wits end sometimes to include in the view just what the producer wants and no more. The most useful lenses are the standard (3-inch) and the "wide-angle" (2- inch). Lenses of 5-inch focus or longer are useful only in travel work for taking scenes and views of objects which cannot be ap- proached closely, and for making pictures of trick or spectacular nature. Lenses of great focal length will require extension mount- ing tubes, since there is no bellows extension for the increase of distance between the lens and the film window. Focusing. The motion-picture camera has no bellows, but is focused by sliding the lens in its mount. The barrel may have a rack and pinion with knob for racking the lens in and out, or the lens may be mounted in a screw flange and may be moved back- ward and forward by turning the lens in the mount. A limited movement only is thus obtained as compared with the movement of the bellows of a fixed camera; but in the motion-picture camera the very short focal lengths of the lenses require but small move- ment for their maximum adjustment for focus. It is convenient to have the lens mount so arranged that when the lens is as far back as possible, at the limit of its motion, it is in universal focus for its largest or most commonly used aperture. By "universal" focus is meant that position of the lens in which distant objects are in focus upon the screen, nearer objects being to some extent blurred. At //16, objects from the extreme distance and up to 30 feet from the camera are all in focus with the proper adjustment; with //32, objects up to 20 feet; at //6.3, objects up to 100 feet. The lens position for universal focus depends upon the diaphragm stop used. In a crude camera it may be necessary to open the camera case and focus by looking directly upon the film window. The camera should have a focusing window for enabling the operator 132 MOTOGRAPHY 65 to see the image in the film window without opening the camera. This window may be either in front of the fihn or back of the film, and of course must be closed after focusing to prevent leakage of light to the film while being exposed by the crank. As the dis- tance from the focusing peephole to the image in the film window is several inches, it is customary to have a lens for focusing which both enlarges the image, making accurate focus easier, and inverts the image so that the view is seen right side up. Focusing may be done either upon the sensitive film which has been threaded through the camera mechanism, or a piece of very thin ground glass or of celluloid which has had its surface "ground" similar to ground glass, which may be placed in the film window for focusing, being removed and the film threaded up after focusing. Particularly for work in a city street is it desirable for the operator to set up his camera, get his field and focus, and be ready to turn in the shortest possible interval, and particularly for such work will the dead stop for universal focus be found desirable. Control of Image. Aside from lens length and point of view, the operator has the sliding lens board, the equivalent of the rising and falling front of the fixed camera. The short focal length of the lenses used requires caution in using the sliding lens board, since the definition of the image is sacrificed when the center field of the lens is not used. The sliding front may be assisted by tipping the camera sHghtly when the resulting distortion is not objectionable. The camera man's most powerful element of control of image is found in the selection of the point of view, and his tactful control of the producer in avoiding objectionable camera positions and in obtaining such camera stands as will lend some pictorial value to the images of the film window. Shutter. The disk shutter is universal for cameras. A disk of thin sheet metal revolves in a plane between the lens and the sensitive film in the film window. An opening is cut in the shutter, or a part of the disk is cut away, and the light is cut off from the film by the shutter except while the opening is passing the lens. The opening is adjustable. Such a shutter usually is made of two half-disks mounted upon a shutter shaft; by setting these exactly over each other, the shutter will be "half open, half closed," or by adjusting them upon each 133 66 THE MOTION PICTURE other the open space may be reduced to any desired fraction of the "open" area. Some shutters are pro\aded with adjustments whereby the shutter exposure may be changed while the camera is being turned. This is objectionable because it renders the shutter more liable to getting out of adjustment accidentally. Exposure Time. The usual exposure is "three-eighths open." ^^^len taking pictures at the rate of fourteen per second, this figures out I of 1/14 of a second, 1/37 second, or 27/1000 second, that the lens is open. The photographer experienced with shutter efficiencies in fixed camera work may note that tliis is an actinic value and not a mechanical value, and that the exposure mechanically is corre- spondingly of greater value than the figures seem to show. One-thirty-seventh of a second actinic value is much more than the average of snap-shot hand camera exposures. It is a longer exposure than would be possible with the fixed camera for moving objects and longer than is customary with hand cameras. ^Moving objects will show a blur in the negative; when projected upon the picture screen, the blurred object of one image will fade into the same blurred object in a difi^erent position in the next image, and smooth motion will be simulated, the object becoming sharp again when its motion becomes slower. Exposure Control. The time or length of exposure being fixed by the mechanical Hmitations of the art of the motion picture, and the negative film being of but one available speed or sensitiveness, the sole means remaining to the camera operator for adjusting his ex- posure value is the diaphragm stop. If the light is poor, the stop must be opened, and if the stop at its full does not give enough light, the picture cannot be made unless by "trick" processes. In the matter of limiting quantity of light, however, two elements come to the relief of the motographer. First, because the negative is to be used for printing a transparency, a negative may be of value which would be useless for opaque paper prints; and second, the motion in the projected film picture will keep the attention of the spectator on the high lights and cause him to overlook the lack of detail in the shadows. Successful motion pictures may be obtained from exposures so low in light value that nothing but failure could result with the fixed camera. As the diaphragm stop is the only variable element available 134 MOTOGRAPHY 67 to the motographer, Table I has been prepared giving the proper diaphragm stop for each day and hour of the year, Eastman fihn (Watkins 250, Wynne 111), | open, 14 pictures per second (1/37 second), latitude of the northern part of the United States: TABLE I Exposure Chart Jan. Feb. Mar. Apr. May June July Aug. Sep. Oct. Nov. Dec. 5 A M. /.8 6 A.M. //8 //ll //16 //ll //8 7 A.M. //4 //ll //16 //22 //22 //22 //16 //ll //4 //■I 8 A.M. //ll //16 //22 //22 //22 //22 //22 //16 //ll //u 9 A.M. //16 //22 //22 //32 //32 //32 //22 //22 //16 //16 10 A.M. to 2 P.M. //22 //32 //32 //45 //45 //45 //32 //32 //22 //22 3 P.M. //16 //22 //22 //32 //45 //45 //32 //32 //16 //16 4 P.M. //ll //16 //22 //22 //32 //32 //22 //16 //ll //ll 5 P.M. //4 //u //16 //22 //22 //22 //16 //ll //4 //■I 6 P.M. //8 //ll //16 //ll //8 7 P.M. • //8 ' This table is subject to all of the corrections given for the ex- posure table for the fixed camera. "Double exposure" for the motion-picture camera means only the next larger diaphragm stop, that is, the next lower number. "Four times exposure" means two numbers lower, and so on, each lower number doubling the exposure. "Half exposure" means the next stop number higher than the one given in the table. If a ray filter be used, the diaphragm stop must be opened to compensate, two stop numbers lower for a "four times" filter, one stop number lower for a "two times" filter, or three stop numbers lower for an "eight times" filter. Eastman film is orthochromatic, and gives color values and cloud effects when used with an orange ray filter. It is of the sensi- tiveness used for "speed Kodaks," one and a half times as fast as ordinary Kodak film, and twice as fast as a Seeds 26x dry plate. In addition to all of the corrections for clouds and nature of subject, as used for fixed photography, a quarter of the exposure 135 68 THE IMOTION PICTURE may still be suflBcient in view of the nature of the motion picture and the tendency of the spectator to view the high lights of the moving objects and neglect the shadows. In computing an exposure, the object in motion is the center of interest, and all other parts of the picture are negligible. For instance, in a picture of an airship outlined against the sky, the sky correction (one-tenth exposure) is correct even though there are foreground objects; when the picture is projected, the spectators will look at the airship, not at the foreground. In a scene where one actor occupies the center of the stage and the play of expression in the face is the only action of the scene, it is poor motography to over-expose the white face for the sake of getting detail in the half- lighted studio background at which none of the audience is looldng. Exposure Meters. The exposure meter used for fixed-camera work is entirely suitable for motion-camera work, the speed of the motion-picture film being taken as 250 Watkins or 111 Wynne. Two further points must be borne in mind. First, that the 1/37 exposure given by the motion-picture camera with its 3/'8-open shutter working at fourteen revolutions per second is full actinic value for the time, the equivalent of a focal plane shutter in a fixed camera, and much greater value than the similar schedule of the automatic leaf shutter common on fixed cameras. Second, that the motion-picture negative will stand an under-exposure of a quarter exposure or even less than that and yet give a successful print. To judge by the product of some studios and factories, the manufac- turers prefer their films that way. In using the Wynne meter, the light value or "actinometer time" is taken in seconds and the number of seconds thus found is set up opposite the plate speed number. The number representing the seconds of sun time is found upon the inner scale and the speed (111) of the motion film is found on the outer scale of the meter. These two are brought together. Now opposite the exposure to be given, read the diaphragm stop to be used. The exposure 1/37 is the line between 1/32 and 1/45. In the illustration, the sun time six seconds is set opposite the film speed 111, and opposite the 1/37 exposure line is read a diaphragm stop between f/7 and //8. In using the Watkins meter, the light time is taken in seconds and is set opposite the 1/37 exposure; opposite the film speed 250 136 MOTOGRAPHY 69 then is read the diaphragm stop to be used. Thus, when a light time of 3 seconds is taken, 3 on the light scale is set between 1/32 and 1/45 on the outer ring which is both exposure and plate speed scale. Opposite 1/250 will be read either U. S. No. 8 or//ll. In using any meter in the field, the correction for the nature of the subject, and for the allowable or desirable under-exposure of the film, is always to be made. If the camera man should find that his critics or "bosses," whosoever they may be, prefer thin negatives resulting from under-exposures, the film speed may be taken as Wynne 256 or Wynne 512 and the meter scale will give directly in its scale reading the required diaphragm stop with the correction for under-exposure — as compared with fixed camera work — as desired. In the daylight studio, the meter will show the value of the daylight upon the scene set, and will give the stop required. If the stop required is larger than can be had in the lens, the meter will show by a proper interpretation what proportion of the necessary light is had, and the remaining proportion of light may be supplied by lighting a partial battery of lamps. In the artificially lighted studio scene, the exposure is constant and is known from experience, being always the same, day or night, scene after scene. The exposure value for a scene lighted with standard Cooper- Hewitt mercury-vapor lamps rated at 700 candle-power may be calculated according to the following formula: Take the average distance from all lamps to waist height of an actor standing in the middle of the scene set, measured in number of feet. Midtiply this number by itself, divide by ten times the number of lamps, and the qvxitient is the correct exposure at //16. Thus, with 100 lamps averaging 10 feet from the middle of the stage setting, the solution is 10X10 -^ (10X100) -= 1/10 second at //1 6, or 1/40 second at//8. Therefore, for such a setting, stop//8 should be used. ^Miere the light is insufficient, it is possible to open the shutter of the camera to ^-open-2--closed, thus increasing the exposure by one-third of its light value. By turning the camera slowly, the ex- posure value is further increased, but this can be done only with the result of speeding up the resulting action when the print is pro- jected. It is the producer's option, not the camera man's. 137 70 THE MOTION PICTURE Panoramic %'iews of poorly lighted scenes without moving figures, as the interior of churches, court yards, statuary, conserva- tories, etc., and factories with the machinery motionless, may be made by lengthening the exposure by turning slowly, but only by the most skilful actors is it possible to put any lifelike movement into such a picture. Duplicate Exposures. Exposure values are always doubtful even when calculated from the meter, ^^^len two cameras are working side by side to make duplicate negatives of the same scene, it is well to have the diphragm stop of one camera one number or even two numbers above the other, giving the developing room a better chance to get one really perfect negatiAe out of the pair of films. Duplicate exposures upon a scene are made for several reasons : That one negative may he held in reserve in case of accident in a printing machine or elsewhere. That two exposures may be available in case of accident before or during development. That one negative may be exported for printing abroad. That two filtyis may be exposed as assurance against accident in one of the cameras. That cameras of different makes may have their products confused. Trick Crank. The main crank gives a large number of pictures per second, and the camera operator acquires a skill in turning it which enables him to take fourteen pictures per second with great precision. AMien it is desired, for trick picture purposes, to take the pictures at a slow speed — that the action may be speeded up in projection — it is possible to turn the main crank at half speed, but better to use a "trick" crank, which the camera man may turn at his normal accustomed speed. This trick crank is geared down in the camera and gives only half the inside speed, or less, sometimes making only one picture per turn of the crank. The opening in the shutter must be changed accordingly, half the opening for half the picture taking speed, in order that the exposure time of 1/37 second may be maintained. Correction by the diaphragm is possible, but results in too much motion in the object if rapidly moving. Where the main crank is detachable, it may be put on either the main shatf or the trick shaft of the camera. 138 MOTOGRAPHY 71 Reversing. The camera may reverse the action in three methods, of which the third mentioned is the usual one employed. First, some cameras are so constructed that the handle may be turned backward or forward. When making reversed scene with such a camera, load the film into the take-up position and the take-up box into the feed position, then change the take-up belt or gears to wind upon the feed spindle position which now is reversing take-up. Second, mount a reversing prism in front of the camera and turn as usual. Third, the camera is provided with a tripod screw or socket in the top. Turn the camera top down on the tripod, and turn as usual except that the crank now is upon the opposite side of the camera from that to which the operator is accustomed. Finders. A finder for focusing is not convenient for deter- mining the view while panoraming. It is possible to panoram accu- rately by sighting along the side or top corner of the camera, par- ticularly when two operators are working the camera, but when there is but one and he stands at the side of the camera, turning two cranks at the same time, a finder bringing the view into convenient position will be an advantage. Indicator. A film-measuring device w^orks upon the constant feed of the film and has its dial outside. The indicator can be reset by the operator. The operator sets the hand to zero when loading the camera, and the hand then wdll read upon the scale the length of film turned through. Know^ing the length put into the camera when loading, the operator can by subtraction know the length still remain- ing. When not enough film remains for the next scene, the camera must be reloaded, the lens being capped and the film "marked," and the remainder of the film wound through into the take-up box before opening the camera to reload. It is possible to make the dial of the film indicator read "remain- ing film" instead of "used film," the operator setting the hand back- ward to the equivalent of the film length when loading the camera, and the hand reading upon the dial at all times just the amount of film remaining as the hand approaches zero. Marker. The marker is a push button or pull knob on the outside of the camera, and usually operated to punch a hole in the film near the film window. Its use is to indicate on the film the end of a scene. For the benefit of the developing room, a "test exposure" 139 72 THE MOTION PICTURE of a few feet of film is made before beginning the taking of the scene for the final motion picture negative. The camera is set up, focused, and closed ready for use, the light-struck leader is turned off into the take-up box, and then several turns of the crank are given, ex- posing a dozen feet of the film before the action is ready to begin. The "marker" then is operated to punch a hole in the film, or two or three holes with single picture space between them. The scene then is taken. In the developing room, the leader of film ahead of the marker holes may be cut off and developed to learn whether the exposure is correctly timed, and whether regular or special de- veloper shall be used in the development of the scene of the film. ^Mien the unused film in the camera is not enough to cover the length of scene which the producer is about to enact before the camera, the marker is operated again and the remainder of the film wound through. A memorandum of the number of feet of unex- posed film is sent with the reel when it goes back to the factory, that length is measured off and the film is cut at the marker holes, thus sa\4ng the unused film. Bianchi Camera. This camera does not use the intermittent motion, but uses a continuously moving film and passes the rays of the image through a revoh-ing prism. The only difference to the camera operator is the method of threading up the film. Hamacek Camera. This camera uses no sprockets, and the film is not perforated. The method of use is in all ways similar to the camera using perforated film, except in the detail of threading. No matter what the mechanism of the camera, the operator should understand it thoroughly, and keep it clean, properly oiled, and in perfect adjustment and nmning condition. Factory Floor Plan. Fig. 15 shows a floor plan suitable for a small motion-picture film factory. This shows only the "photog- rapher's" department, the sales offices and the studio being adjacent or elsewhere. The plan is self-explanatory outside of the developing room and the light-trap entrance to the developing and printing rooms. The perforating room is entered only through the printing room. Partitions form a tortuous pathway into the developing room and printing room from the shipping room, permitting the free access to and from these rooms without doors, and without danger of accidental 140 MOTOGRAPHY 73 light flashes into the rooms by reason of the opening of the doors. At the end of the developing room next the washing room a large door shown double is of sufficient size to permit a developing cage to pass through. Because of the opening of this outer door to the developing room, there is no door between the printing room and developing room, passage being had through the entrance passage- ways, or by a turntable in the partition. Development of Films. Cages. For development, the exposed or printed film is wound spirally upon cages 3 feet in diameter and 5 feet long, one such cage taking a 200-foot roll of film. The ends ■ 1 1 DEVEL0PIN6 ROOM 1 1 PERIVPATIN6 -.PPINTIN6 1. WASHING 1 /POOM / ROOM 1 2 3 4 ' 6TAININ6 eo ' 60FTENIN6 1 ROOM \ \ J JTORASe / \ \ "- — \ DI?YIN6 1 , ' ffOOM 1 OFFICe IN5P5CTINe PACKING ai 5mPPIN6 ROOM 1 Fig. 15. A Film Factory Floor Flan of the cage are built like wheels of feUies and spokes, the ends being connected by round polished wood rods, the whole appearing like a large cylindrical cage with an axle through the center. Trays. The developing tray is of wood, 6 inches deep, and has within it a zinc trough curved with the curvature of the develop- ing cage. Standards at the ends of the developing tray take the axles of the developing cage and support its surface within h inch of the bottom of the zinc tray which it fits closely but does not touch, turning freely on. its axle. A few gallons of developer in the zinc tray will develop several cages of film, the cage being turned con- stantly during development. The wood tray catches what developer splashes over the zinc. 141 74 THE MOTION PICTURE Trays for washing do not have the inner zinc trough, being filled with water, running water if convenient. The hypo trays also should have an abundance of hypo solution, and do not require the inner zinc trough for economy of solution as is the case with the developer. Room. Four trays are shown in the floor plan, No. 1 developer, No. 2 water. No. 3 water, and No. 4 hypo fixing bath. The cages are handled by the developing room operator and an assistant, lift- ing at the two ends of the axle. The routine of development is as follows : Developing. Through the large door, a developing cage is brought in and hung over the developing tray on high journals, a few inches above the developer. The large door being securely closed and the room lighted by red light only, the operator opens a tin box of exposed film, attaches one end with a clamp to one of the slats of the cage, at one end; the assistant turns the cage and the operator feeds the film on from the roll, attaching the end when all is fed on. The cage now is set down on lower journals and turned in the developer by the assistant while the operator watches the images until fully developed. The cage then is lifted to the wash water tray, turned a few times, then to the second wash water and turned a few times, then to the fixing bath. ^Mien the milkiness is gone, the big door is opened, the cage with the wet film is carried out to the washing room, and another empty cage is brought in and the big door closed again. Wofthing. Two assistants in the washing room wash the film through several waters or in running water to free it from hypo, then turn it in a tray of diluted glycerine — 1 part glycerine, 33 parts water — for a minute and carry it into the drying room. Drying. The drying drums differ from the developing drums in having smooth surfaces instead of being cyhnders of slats. Also, they may be larger than the developing cages, since they do not have to be handled — 4 feet in diameter by 8 feet long is reasonable, and will hold 600 feet of film. Two attendants are required in the drying room. The end of the film is attached to the drum with a thumb tack and one attendant turns the drum by hand, while the other attendant guides the wet film from the developing cage to the sur- face of the drying drum. When the end is reached, it is attached 142 MOTOGRAPHY 75 with a tack or push pin, and the drying drum is belted to a motor wliich drives it continuously until the film is dry. The developing drum is sent back to the washing room for use again in the develop- ment of films. When films are dry, they are unwound from the drying drums to reels or into baskets and taken to the inspection room, if positives, for shipment, or sent to the photographer for inspection and proofs, if negatives. Making Titles. The making of a title is a simple case of the making of a motion picture of an object which as a general rule is not moving. The titles are set up and properly lighted and pho- tographed with a motion-picture camera, using the length of film called for by the synopsis. Most conveniently, titles are prepared in batches, a number of titles being photographed upon a long strip of film which then is developed in the usual way and a proof print taken. The titles then are cut apart and spliced into the motion scenes as required for the complete film pictures. To make titles with movable letters, a table top is covered with black cloth and a motion-picture camera is permanently mounted above it and focused upon the surface of the table. Lamps are placed around the table for lighting the title. The light need not be excessively bright, as the camera may be turned slowly and with a large shutter opening. Upon the table top, white letters are arranged to form a title, the title is photographed by turning the camera above the table, and the letters immediately are arranged again for the next title. Letters cut by dies from white paper may be bought in various sizes, or porcelain letters, such as are used for signs on window glass, also are obtainable in various sizes and in various styles of lettering. Lines upon the table top show the edges of the field of the camera and within the lines the desired title is formed, arranging the letters of each line against a straight edge which is removed before pho- tographing. The table top is a convenient means for copying all kinds of titles, merely laying the title upon the table, if the suspended camera is arranged so that it can be moved to different heights to provide for different enlargements of the various titles, and further arranged so that it can be focused conveniently. 143 76 THE MOTION PICTURE In photographing either a yellow telegraph blank printed with black ink or a white telegraph blank printed with blue ink, a heavy yellow ray filter should be used over the lens to increase the contrast in the resultant title. A suggestion for the photographing of titles is that a slow film be used for the negative instead of the extremely fast sensitive film used for the motion scenes, since a slow film will give a greater con- trast in the resulting titles. A reversed title is made as follows: With a title in black letters on a white card, photograph the title and develop as usual ; this nega- tive has clear letters on a dense background. Make a reversed print by printing with the celluloid side of the negative against the gelatine side of the printing stock. This print when examined will have its letters reading backward, like a negative, but will have black letters on a clear background. This reversed print is the reversed negative, to be spliced in with the negatives of the motion scenes for printing the titles for the finished pictures, the printing for the final scenes being gelatine to gelatine, as for the motion scenes. In the print, the reversed title will appear with clear letters upon a dense back- ground, making the title when projected show white letters upon a black screen. Printing. Room. The proper location for the printing room is between the perforating room and the developing room, as shown in the floor plan of Fig. 15, with entrances into both perforating and developing rooms as conveniently arranged as possible. The print- ing room constantly requires supplies of perforated film from the perforating room, and constantly supplies the developing room with printed film for development. The connection between the print- ing room and the developing room is particularly close, since by immediate development of the film after printing the developing room operator may be able to note errors in printing which might spoil large quantities of film if printed far in advance of development. The printing room is provided with printing machines and power to drive them. Machines. Obviously, a negative for a reel of film 1,000 feet long cannot well be handled in a contact printing frame such as is used for printing the negatives from a fixed camera, nor is it prac- ticable to cut the negative into sufficiently short lengths for such 144 MOTOGRAPHY 77 contact printing even if proper results could be obtained in that manner. Since the standard roll of film furnished by the makers of the raw film is 200 feet, and since the developing cages are also of a size to handle the 200-foot rolls of fihn, the 1,000-foot negative is cut into five pieces of 200 feet each and the 200-foot length is the standard length through the factory up to the time for splicing together into the reel for shipment to the film exchange. The printing machines are of two types, stepping and rotary. The stepping printing machine has a film window and an inter- mittent film movement. There is no lens. An incandescent lamp is arranged to shine upon the film window, being adjustable in dis- tance from the window. The lamp is enclosed, to prevent leakage of white Ught into the printing room, and the film window is backed with ruby glass to permit the operator to see the image in the win- dow and to prevent leakage of white light. A framing device is a desirable feature of a stepping printing machine, and a necessity if the intermittent film movement is not entirely reliable. A project- ing motion head may be used as a printing machine, or in the case of amateur work the lens may be removed from the camera and the camera may be used as a stepping printing machine. The pro- jecting head has the framing device, while the camera has not, and either requires the printing lamp with its adjustment for distance to be added, after removing the lens. Two feed reels are provided, one for the negative and one for the raw positive film stock, the two ends being started through the film window together, film sides together and the negative next the light, so the light shines through the negative upon the positive. The shutter remains upon the machine. The operator then applies the power and keeps the image framed in the film window. A take- up reel rolls up the printed positive film, but it is customary to run the negative into an open basket and to rewind it before making the next print, so that the printing always proceeds from the same end of the negative. The stepping machine will print from 10 to 100 feet per minute. The continuous printing machine is much faster in operation than the stepping machine, printing from 40 to 500 feet per min- ute according to the quality of the negative, but the greater perfec- tion in mechanism required renders the continuous machine difficult 145 78 THE MOTION PICTURE to construct, and the greater accuracy required in adjustment and operation sometimes results in losses of film not encountered with the stepping machines; and if the defective film be not discovered and discarded, then the manufacturer is giving to his customers an inferior product, which is the worst condition of all. In the continuous machine, the two films, negative and positive, are wound with a steady motion from the feed rolls to the take-up rolls, passing together in contact in front of a window lighted with the printing lamp. This sounds very easy, but the slightest slipping of one film upon the other will produce an effect upon the picture screen when projected which will drive a spectator to insanity, and the slight- est lack of registration in the perforations of the two films will pro- duce the undesirable slipping. Exposure. By the term "exposure" in printing, the same mean- ing is conveyed as in using the camera, namely, the amount of light which is permitted to pass to the sensitive film. In the printing machine this depends upon the intensity of the printing light in the window, the size of the window or shutter opening, and the speed at which the printing machine is driven. With either the stepping or contiiuious machine, the amount of exposure may be regulated without stopping the machine by changing the distance of the printing lamp from the film; doubling the distance cuts the exposure value by four; and dividing the print- ing-lamp distance by three, multiplies the exposure value by nine, according to the law of squares. With either the stepping or continuous machine, the amount of exposure may be regulated by changing the speed of driving the machine. This regulation does not apply the law of squares but gives a lineal inverse ratio to the exposure, half the speed giving double the exposure, double the speed giving half the exposure, and so on. With the stepping machine, the opening of the shutter may be changed from i-open to j-open or |-open, the change in exposure value being in direct ratio to the size of the open portion of the shut- ter. It is possible to construct printing machines in which the shutter opening may be changed without stopping the machine, inasmuch as some motion-picture cameras have this feature in the shutter and such a camera shutter may be used in a stepping printing machine. 146 MOTOGRAPm^ 79 With the continuous machine, the size of the film window or slit of light shining upon the film may be changed without stopping the printing machine. The printing window or spot of light which impresses the image upon the positive film as the two films pass may be large enough to cover a full image, or two images, or may be only a quarter of an inch in width, or even narrower, extending always from side to side of the film. The narrower this band of light, the less injurious to the resulting print wnll be any lack of accuracy in the adjustment of the printing machine, or in the perforations of the two films. With a narrow band of light, the printing lamp must be nearer, or brighter, or the speed of the machine must be slower. Incandescent electric lamps are used because of the uniformity of their illuminating power. Film Adjustment During Printing. The 200-foot piece of negative is composed likely of half a dozen motion scenes, some inside studio work and some outdoor work, interspersed with titles. That all these short negatives, made under varying conditions, should have the same printing density and require the same exposure in the printing machine is quite unlikely. Each 200-foot length of negative is inspected by the chief photographer and ticketed for exposure. Following is a sample exposure ticket for a stepping printing machine having lamp distance as its only adjustment w^hile moving. First Negative, "The New Boarder" Speed 25 feet per minute Shutter |-open 12' title 3" 30' interior scene IC" 6' title 3" 20' interior scene 10" 10' outside scene 8" 60' interior scene 10" 6' title 3" 40' outside scene G" The number of feet given at the beginning of each line of the ticket indicates the length of film which is taken up with the title or scene, that the printer may anticipate the instant when the next change is to be made. The exact instant is known in a stepping machine by watching the images of the negative in the film window. In a continuous printing machine, the images are blurred by the 147 80 THE MOTION PICTURE steady motion, but the change in density of the negative will be noticed, and further guidance may be had by cutting a small notch in the edge of the negative film and arranging an electric circuit to tap a bell as the notch passes. The lamp of the printing machine is movable by a lever which is provided with pointer and scale and with movable stops which may be set to stop the lever at different lamp distances. To print the negative ticketed according to the specimen ticket given, the printer sets stops permanently at 3" and 10", the limiting positions, holding the lever against the stops for that portion of the negative for which those stops are correct, and holding the pointer on the scale at the proper number for other sections of the negative. For use with a continuous machine, the exposure ticket would give at the head the film speed and slot width, or would give at the head the speed and lamp distance and then give the slot width for each portion of the negative, the adjustment being made by slot width rather than by lamp distance. Making the Exposure Ticket. By experience, the photographer in charge can judge the printing exposure required by looking through the negative, or comparing it with standard specimens. The first print should be developed promptly and inspected, the ticket being changed if required. In case of doubt before printing, the negative may be run through the printing machine under known conditions with a foot of positive film, this foot being attached to the develop- ing drum with tacks while a roll is being developed. By the result- ing specimen print, the proper exposure may be judged. Developing Prints. Processes suitable for developing lantern slide plates in fixed camera photography are suitable for the motion- picture positive prints. Hydro-metol or hydro-quinone developer are usual. The positive print is developed, washed, fixed, washed, softened in glycerine, and dried. Inspection. After drying, the prints are carefully looked over, foot by fcot, for defects of any character whatever. The five 200- foot pieces of each 1,000-foot reel then are spliced together in proper order and the reel is ready for packing and shipment. Isolated defective images are cut out and a splice made. AMiere more than a limited number of images in one place are found defective in the print, the place is marked and a short length printed from the negative 148 MOTOGRAPHY 81 and substituted for the defective length of film. Hand staining, hand coloring, and hand spotting of the prints are done in the inspec- tion department unless of such quantity that a special department is created for the work. After passing the inspection, the film is packed in its sheet iron shipping cases, one reel in a case, and sent to the storage room until required for shipment. Print Spotting. Very little hand work is done upon the print after it is dried, but sometimes a reel of negative will have a scene which requires hand work on each print to bring it up to the standard of the factory, or to make it passable at all. If the scene cannot be retaken to secure an improved negative, the hand work upon the prints must be done. In many instances, it is possible to balance the cost and inconvenience of necessary hand work upon prints or negative against the cost of reproducing the scene and securing an improved negative. Staining. Staining of a print is done in the wash-room as a part of the washing process, and is done in the same manner that a laundress uses in bluing her clothes. The last rinse water, or the glycerine bath, or both, are charged with an aniline dye or other water-soluble dye stuff, and the film takes the color in passing through the baths. This produces a stained gelatine film on which the silver image is still black. \^Tien projected it produces a black picture upon a tinted screen. It is largely used for reversed titles, producing the title in tinted letters upon a black picture screen and giving a more pleasing effect than a plain white title. The Western Union Telegraph Company uses a yellow telegraph blank, and titles show- ing such messages sometimes are stained yellow to lend realism to the title. Toning or Monochroming. In the toned or monochromed film, the gelatine remains clear and the shadows of the image are colored, giving the effect upon the picture screen when projected of a picture painted with color upon a white sheet. The processes may be classi- fied as those which obtain the colored image in the first development of the positive film and those which obtain the color by subsequent manipulation. With hydro-metol or hydro-quinone developer having no bromide or insufficient bromide, the image will come up in olive green. Be- cause of the absence of bromide, the development is very rapid 149 82 THE MOTION PICTURE and difficult to control, and the printing exposure must be corre- spondingly short to secure a good print. With a proper adjust- ment of printing exposure, developer strength and bromide, neutral blacks can be secured. With a developer rich in bromide, develop- ment is slower and the resulting film shows shadows tending toward brown, and with still more bromide the print shows purple or even red. Printing exposure must be increased to avoid unduly prolonged development. With a printing exposure of ten times normal for black and a development period of ten times normal for black and with sufficient bromide in the developer to restrain the development to that period of time after that exposure, the resulting images will be a purple which tends toward red. ^Nlonochroming of this class is done in the developing room, before the print is passed out to the daylight washing room. Processes in which the colored image is not obtained in the first development may be carried on in the daylight washing room, before the film is bathed in the glycerine bath. Re-developing for sepia, and intensification and toning for blue, green, and red may be done as for lantem-shde plates. The literature of the photographic art is amply provided with formulas for these processes. Repeater Printing. Where it is desired to give a special tone to a single scene or short portion of a complete film picture, the negative for that scene may be omitted from the complete negative, a few inches of blank film or special code film being inserted instead. The short scene now is placed in the printing machine and the two ends stuck together, forming a belt. A 200-foot roll of positive film is started through the printing machine, and the belt of negative is printed repeatedly for the entire length of the positive roll, if required, or for as many rolls as are required. A large number of repetitions of a short scene thus may be developed and toned at once, being cut apart after drying and spliced into the regular prints at the proper place, the bit of dummy film put into the negative acting as a guide to the inspection room to put the special scene in its proper place. Hand Staining. Titles or short scenes forming parts of long pictures and re(|uiring staining may be done more conveniently by staining each positive print with a brush, by hand, than by special work in the developing or washing room and the subsequent splicing 150 MOTOGRAPHY 83 required in the inspecting room. One of the desirable features of hand-staining is that there is no danger of errors in the order of scenes in sphcing up, since the sphcing is avoided. The slight unevenness of hand-staining is entirely negligible in reversed titles. Hand-staining is done in the inspection room after the film has been dried. Coloring Films. Hand Process. The primitive method is to take the positive film and a set of brushes and water colors and color each of the small images as though they were so many separate and distinct photographs, as indeed they are. In connection with this method of hand-coloring the intermittent mechanism of the camera or projecting machine may be used with great convenience. The strip of film to be colored is arranged over a glass plate through which the light may pass, since the colorist should look through the film to get the effect of the color. A leader is spliced (or pinned) to the film to be colored and is taken through an intermittent move- ment controlled by the colorist's foot upon a pedal, that by a single pressure upon the pedal the film being colored may be stepped for- ward one picture. This change will take place very quickly, so that the colorist seems to be worldng upon the same image. Taking the blue color for the sky, the colorist colors the sky of the first image, lifts the brush, and presses the shift pedal, proceeding to color the sky of the next image without lifting the hand from the position of applying the color, merely lifting the brush from the film while shifting the images. Having colored all the skies, a certain tree, house, or chimney is colored throughout the length of the scene; then the moving figures are colored, the brush of the colorist follow- ing the figure over the small picture as the figure moves in the action of the play. Taken in connection with the pedal shift, the coloring of some film scenes becomes surprisingly rapid. Hand-colored scenes are spliced up with monochromed and stained scenes and titles. A "full hand-colored film" picture has been reported by colorists as requiring a day's labor of a worker for each 35 feet of film. The time for different scenes will vary widely, and this 35 feet per day may be taken as a maximum of labor in hand-coloring. Stencil Process. A stencil is made for each color to be applied to the film, and the proper colors are applied through the stencils with brushes operated by hand. Assuming that it is decided to color 151 84 THE :\IOTION PICTURE a scene with three colors, red, yellow, and blue: Four prints of the scene are taken by the colorist; upon one is painted with red all of the parts of each image which are to be colored red in the finished colored picture, just as the hand colorist would finish with the red before taking up another color. The colorist next takes the yellow, but takes also the second of the prints and colors upon the second print all of the parts which are to be colored yellow in the finished picture. The blue color and the third of the prints now are taken and all parts to be blue in the finished picture are colored blue in the third film print. By looking through all three of the prints together, the colorist may judge what the result of the combination of colors upon one print will be, and may change any of the prints. When finished, there are three colored prints, each of which bears but a single color. If more than three colors had been decided upon there would be more than three of the partly colored prints. The three prints now are cut with a sharp knife or with stenciling chisels, re- moving all of the colored portions and leaving all of the uncolored portions. The result is a set of stencils, in one of which every red spot on the finished colored motion film is indicated by a hole in the stencil, in another of which the yellow is represented similarly by holes, and in the third of which the blue is represented by holes. The fourth print of the scene is taken, the red stencil is placed upon it and a brush charged with red ink is run over the stencil. The yellow stencil then is placed upon it after removing the red stencil and a brush charged with yellow ink is run over it. The yellow stencil being removed, the blue stencil is placed upon the film and a brush charged with blue ink is run over it. The result is a tri- color print with the colors stenciled upon the black lines of the photographic print. A monochromed or stained print may be sten- ciled over in the same way, producing desired effects. Machine Process. The machine feature consists of the appli- cation of the ink through the stencil by a stenciling machine. An illustration from the published American patent of a French film coloring machine is reproduced in Fig. 16. The method of making the stencil is the same as for a hand-stenciled film. The operation is as follows: Having the stencil for one color, and the film to be colored, each in a roll, the roll of stencil is placed in the machine at 23 and the roll of film to be colored is placed at 24- The ends then 152 MOTOGRAPHY 85 are taken through the guide blocks 25, the stencil band being shown by the dotted line 2 and the film to be colored being shown by the solid Hne 3. These are passed together over the large roller or drum 1. Just above this drum there is a short endless band of ribbon 21. This, the inventor tells us, should be of velvet, so that it offers a soft brushlike surface which is well suited to pass through the holes in the stencil band and touch the film to be colored, which lies just underneath. The band 21, which is really an ink brush, runs over three rollers, and runs in a direction opposite to the direction of the film and stencil band, the directions of the movements of the parts being shown by the arrows close to the different bands; thus there is a considerable brushing effect between the inking band and /:-> Fig. 16. Film-Coloring Machine the film to be colored wherever a hole in the stencil band permits the brush band 21 to get through to touch the film. This charges the film with ink or dye, coloring it in every spot where the color is desired, that is to say, everywhere that a hole has been made in making the stencil band 2. The supply of ink is taken from the tank 30 and is carried first upon a short belt 27; it is taken from the belt 27 and put upon the inking ribbon 21 by the revolving brush 26. The whole device is driven by a belt and runs continuously, the teeth upon the drum 1 keeping the stencil band and the film to be colored traveling con- stantly at the same speed, and keeping them always in register. 153 86 THE MOTION PICTURE As in hand stenciling, a separate stencil is required for each color, and the film to be colored is run through as many coloring machines, each having a different stencil and a different color of ink, as there are colors in the finished picture. Waterproofing. The picture film is celluloid upon one side, gelatine upon the other. The celluloid side is hard, glossy, water- resisting, scratch-resisting, dust-resisting, but the gelatine side is easily scratched, collects dust in the scratches and sometimes with- out them, and is ruined by a drop of water, yet requires a moist atmosphere or it will crack by becoming too dry and brittle. In the process called "waterproofing" celluloid or a similar sub- stance in solution is applied over the gelatine film, strikes through the film and unites with the celluloid body, forming a celluloid skin over the delicate film and imprisoning the gelatine like the ham in a railroad sandwich. After that treatment, both sides of the picture film are hard and scratch-resisting, and the film may be washed with water (by special machinery for the purpose) to remove dirt. At the same time, the moisture which made the film flexible is imprisoned with the gelatine and the film remains flexible. The process is patented. Either plain or colored films may be waterproofed, or the negatives in the print- ing room. The proper time for waterproofing is before the film is shipped for use. Packing Films for Shipment. The films are shipped in full reels, or 1,000-foot lengths, wound with open center with the title end out. Each reel is packed in a circular, flat sheet-iron can and then in a wood box; this is a requirement of the express companies. A further requirement is regarding a danger label, which must be printed on red paper not less than 3 inches square, reading as follows: "Moving picture films must not he loaded or stored near a radiator, stove, or other source of heat." The reason for the last rule is that celluloid when warm gives off explosive vapors. Reclaiming Waste. Light-struck films develop black, and these may be sold to film exchanges for leaders. The punchings from the perforating room contain silver, and this may be reclaimed at a profit by a chemical process. The black silver in junk or spoiled film may be reclaimed but usually is not, and the same is true of the silver in the used hypo bath. 154 SCENE FROM PHOTOPLAY, "THE INHERITANCE" Courtesy of Thomas A. Edison, Inc., Orange, IV. J. MOTOGRAPHY 87 PHOTOGRAPHIC EQUIPMENT All supplies needed by the manufacturer, other than cameras, printing machines, perforating machines, and film stock, may be bought in any city in the open market. Buying Cameras. Urban and other English and French cameras may be purchased and imported into the United States at costs ranging from $300 to $400; printing machines cost about the same prices as cameras, for either the stepping or continuous move- ment. The importation or manufacture of cameras in the United States is influenced by the patent situation. Cameras have been offered for sale in the United States at prices quoted from $475 to $2,500. Making Cameras. A projecting machine may be converted into a camera, though rather bulky for field work and requiring some ingenuity to accomplish all the desired features of a camera for both studio and field work. A projecting machine with lens removed and a hooded lamp at the aperture becomes a printing machine almost without change. The pin or claw intermittent movement is preferable to the sprocket for cameras. Buying Films. Several prominent makers of roll films for hand cameras have taken up the manufacture of film for motion- picture cameras and are supplying the market. The price charged is about four cents per foot, unperforated. From some dealers it may be bought perforated. Fire Risk in Storing Films. A rolled film in its tin box is a per- fectly safe proposition at ordinary temperatures. The celluloid body of the film, whether raw film, prints, or junk, gives off an in- flammable and explosive gas, giving it off more rapidly when warm than when cold. A vault for storing films must have a vent; a slow but continuous draught of air through the vault seems a logical pro- vision for safety. CHRONOPHOTOQRAPHY The requirement for scientific study usually is a clear sharp picture taken at regular intervals. The intervals may be short or long, either at the rate of several hundred pictures per second or at the rate of one picture per hour, or one per day. The results occasion- ally are of interest to the general public. 155 88 THE INIOTIOX PICTURE Motographic Microscopy. The image of the thing to be moto- graphed is taken through microscopic lenses to the motion camera in a manner easily accomplished when the lenses are available. The greatest difficulty is found in illuminating the subject sufficiently to achieve the short motographic exposure without destroying the subject by the heat of the source of light. By carrying the light through water or an alum cell before it reaches the subject, and by operating a shutter between the light and the subject so that the light is cut off from the subject except while the exposure is being made, such relief from the heat may be attained as will permit making a motographic picture without destroying the thing motographed. Motographic L Itramicroscopy. Ultramicroscopy is the name given to the process of microscopic study which makes use of the ultra-violet (invisible) rays, recording the image upon a photographic plate and studying it after development. Motographic film has been operated successfully with this class of microscopic study. X=Ray Motograpliy. The invisible X-ray penetrates many solids which are impenetrable by light, and the X-ray is able to influence the photographic dry plate or motographic film. Passing through the body, the X-ray is obstructed by the bones and the heavier and denser organs, throwing a shadow of them upon the photographic surface. By arranging the motographic camera with proper shutter and protective X-opaque shields for the reels and film, motion pictures of the heart in action, of circulation of the blood, etc., are possible. TRICK PICTURES There is no standard "box of tricks" beyond which lies nothing of interest. The interest never ceases when trick-picture making has been begun. This subject was opened under the discussion of tricks in the production of the specimen film, "High-Jumping Johnnie." The thoughts there given were but the simplest of tricks, easily understood or almost guessed by the audience in watching the picture. In addition to the tricks used so much that they may be considered standard illusions in motography, special effects may be attained by tricks as subtle as those of the accomplished magician before his audience. A few of the standard tricks of illusion are here described. 156 MOTOGRAPHY 89 Reversals. The method is to show upon the screen the series in the order just reversing the order in which the pictures were taken. When this is done, all the characters would walk backward, objects would fall from the floor upward to the shelves and table, smoke would float do^Ti into the chimney, etc. Means. Turn the camera bottom up on the tripod — by a tripod socket in the top of the box — this will reverse tlie action. Or print by a special printing machine which steps the film negative in one direction and the positive stock in the other direction. Effects. A nmaway horse may run backward and push the wagon before him just as easily as running forward if there are no people on the street who also would walk backward and thus reverse the illusion. A witch desires to create money from a piece of tallow candle. She melts the candle and pours it on a surface to cool. From this point a picture of coin casts in tallow melting on the same surface is inserted reversed, giving the appearance that the melted tallow magically takes the form of coins and hardens. The witch then ap- parently picks them off as good coins magically created. A sculptor makes a wonderful statue in record time, with a wealth of detail, by skilfully pulHng apart a clay model before the camera, the film then being run reversed whereby he seems to build up, not to tear down. A swimmer, having jumped into the water, by a reversed film jumps just as easily out again, landing safely upon the bank, pier, or springboard, feet first, every time. Speed Pictures. AMien pictures are taken slowly and projected at the standard rate, the action of the picture seems correspondingly faster. Means. Reduce the shutter opening and turn the handle slowly, or turn the camera mechanism, by a specially provided gear to a special handle or shaft called the "trick handle." Effects. Chases may be made to appear much more rapid than they really are, and acrobatic actions on the part of a comedian in the scene may be made so violent as to be ludicrous. The ordinary traffic of a street may be thus speeded up. Dummies. "\Mien a character is required by the plot of the picture to pass through some hazardous experience, such as having 157 90 THE MOTION PICTURE his head cut off or falling from a high building, a dummy is sub- stituted. Means. The action having progressed to the point where the substitution of the dummy is necessary or convenient, the producer cries "Hold it," or "Freeze," and all actors instantly become motion- less and remain so, the camera man stops turning, the actor to be dummied gets off the scene, the producer and his assistants arrange the dummy figure where the actor was, the camera man is given the signal to turn, the remaining actors are given the signal to go on with the action until it is required to replace the dummy with the actor, when the same plan of freezing over the change is carried on. ^Mien the film is developed a short length may be cut out at each of the freezes if need be to improve the picture. Effects. An accident frequently is a part of the plot of the picture. The dummy substitute may be used to relieve the actor from danger in that scene. The film picture story says that the hero rushes to the rail of an ocean liner in mid-ocean, hurls himself over- board and swims to shore. The picture is made by his rushing to the rail, picking up a dummy of himself and throwing it overboard, while the photographer or producer cuts out that part of the film where he picks up the dummy and lifts it above the rail. The swnm to shore and the landing on the distant beach is made in the tank in the studio backyard. Ghosts. Apparitions are made by exposing the negative film twice before developing it. Means. A lens with an iris diaphragm so that it may be opened and closed gradually while the camera is running. The full picture having been made, the ghost is staged upon a stage set all in black and the film already exposed is run through the camera again as noted in advance, so many feet with the lens closed, then gradually opening the diaphragm to about one-tenth of a normal exposure continuing for so many feet and gradually closing if the ghost is to fade away, but suddenly capping the lens if the ghost is to vanish instantaneously. Effects. Only white or light figures may be brought into the picture in this way. The good white fairy may appear thus to wave a signal to the favored hero.. A fairy symbol may appear upon the wall of the room and disappear. The actor may lie dowTi to sleep 158 MOTOGRAPHY 91 and upon a blank wall (left blank for the purpose in th^ scene setting) appears the action of his dream. When the actor thus appearing under the ghost effect is required to take an active part in the play subsequently, or when the figure thus to be produced is not white or substantially so, then the illusion may be made under the plan for dissolving views. Dissolving Views. ^Mien it is desired to have an actor appear in magical manner slowly and to take a part in the action thereafter, the producer causes the actors to freeze, and the camera man reduces his aperture gradually to a closed shutter. The camera man turns his camera back to the point where he began to close, the actor to be produced takes his position and the camera man begins to turn and gradually opens his shutter diaphragm; when the diaphragm is nearly open the action may proceed. INIuch practice on the part of the camera man, or. a special camera with automatic diaphragm is required. Disappearance of any character is effected in the same manner. DouWe Printing. Apparitions may be produced by making the two exposures upon separate films and running the two negatives through the printing machine together with the printing stock, so that the images of both the negatives are impressed upon the sensi- tive print stock. AMiere the object to be added to the scene is a dark object to be added in a light area of the original scene, it is added by running the printing stock through the printing machine v/ith the first nega- tive and again with the second negative, separately. ^Mien a satisfactory print has been produced by the double printing process, the print is copied upon another strip of film stock, thus producing a single negative of the double print, from which single negative as many double-printed positives as may be desired may be had, with less trouble than maldng the total number of double prints. Double Exposures. The making of ghosts by double exposures has been discussed. An explosion in the midst of a number of men may be made by making an exposure of many feet of film in which at a given signal the men all aci upon the cue that the explosion has occurred. The camera man then goes to a black backe;roimd, having noted the place in the film at which the explosion cue occurred, 159 02 THE IMOTIOX PICTURE and runs the film from that point upon an explosion which produces a large amount of white smoke. In the projected picture, the men will be seen enveloped in the smoke of the explosion, which did not occur perhaps until next day. This effect might be made double by printing with the negatives together. It is desired to photograph the semblance of an actress swimming in deep water, presumably at the bottom of the sea. An aquarium is photographed, or an aquatic background scene is photographed upon the motion film. The actress then is attired in light color, the camera is attached near the ceiling or mounted in the rafters, the actress lies upon the studio floor and simulates the movements of swimming. In the finished picture she is seen swimming among the details of the aquarium or aquatic background scene. Mirrors. The appearance of a character in a scene may be effected by a mirror upon the stage, the actor standing off the stage but in view of the camera through the mirror at all times, appearing in the picture according to the amount of light which he receives from lamps near him. ^^'hen lighted he is seen in the play; when darkened, he is not seen. By mirrors also the effect of diminutive characters upon the stage may be effected. A table is backed by a nu'rror which is not noted except as a part of the paneled wall. In the mirror is visible an actor who really stands beside the camera. Owing to the greater distance of this reflected actor from the camera, he will appear of shorter stature than those actors who are viewed directly by the camera without reflection. Thus a fairy of diminutive size may be made to appear. The secret of success in this illusion rests upon the accuracy with which the reflected image is placed in the picture, and upcn keeping out of the picture any intermediate objects between the reflected actor and the directly photographed parts of the picture. Such a picture may be made by double exposure, by double printing, l)y mirror, or l)y blackroom methods. Blackroom. In making a negative of a single figure which is to be printed in with another scene, or in making the second ex- posure of a double exposure, the stage is hung in black or non-actinic color value. With a black stage, the distances of all objects on the stage 160 MOTOGRAPHY 93 are deprived of their perspective values since all connecting features of the stage are invisible photographically. A man sits at a table near the camera. The camera lens is level with the table top. Upon the distant side of the room a girl is dancing upon a black platform of the height of the table. To the eye of the camera, the dancer's feet just touch the table top, but because of her distance the image is proportionately smaller than that of the man. The resulting picture shows the man sitting at a table upon the top of which is dancing a fairy no more than ten inches tall. Stop Picture. The dummy picture is called a stop picture be- cause the camera is stopped while the dummy substitution is made. Pictures in which sudden appearances and disappearances are made, are called stop pictures because the camera is stopped while the actors remain frozen. There is another type of stop picture to which the name is particularly applicable, the camera being stopped after every exposure. Means. A camera making one exposure with one turn of the handle, and which may be left always with its shutter closed by leav- ing the handle in a latched position. Effects. By the stop picture it is possible to give inanimate objects the appearance of life. Dolls are made to walk. Toy animals of the "humpty-dumpty" type are made to perform circus feats. Saws are made to cut off boards without hands; hammers are made to drive nails without hands; shoe laces tie themselves, etc. Method. The stage being set, the handle is turned once on the camera, making one picture, or perhaps several at the beginning before starting the action. The handle being left in its latched position, with the shutter of the lens closed, the moving object of the stage setting is moved slightly. If a box of matches upo;i a table top is the subject of the picture, the inner box is pushed from the cover a sixteenth of an inch. The handle of the camera is turned once. The inner box is pushed an eighth of an inch; the handle is turned again. The inner box is pushed another eighth and the handle is turned again, the person or the hand which moved the match box having been safely out of the field of the camera before the crank was turned. The box b^nng opened a little farther and a little farther each time soon is far enough open to permit the matches to be extracted. One match raises one end to the edge of the box; the 161 94 THE MOTION PICTURE handle is turned once. The match is advanced a sixteenth of an inch and the handle is turned again; another sixteenth, and another, and the handle may be turned several times without moving the match, giving the match the appearance of having paused in its motion to obser^^e whether it is being watched in its escape from the box. Careful study of the extent of each motion of the match and the direction, and the taking occasionally of more than one picture between moves makes it possible to give to an inanimate object a wonderful simulation of life. This class of stop pictures take unlimited time. Perhaps it is a job for rainy days in the studio. Film manufacturers are permitting the popularity of trick pic- tures to decline because of the expense of producing them. The time consumed overbalances all features of apparent economy over ordinary methods for producing the legitimate motion picture. 162 O £g ^ Is CO S^ w c; ■ -) =o O '-;^ X ^^ w ^ s X -^ Ha? w _^ = o -> = :„ Jiff Moo MOTION-PICTURE THEATER MANAGEMENT It is stating a platitude, to say that a motion-picture theater will not operate itself at a profit. If such a condition ever existed, competition and the multiplication of theaters has eliminated it from the ordinary, and has made such instances rare, if not obsolete. Picture theaters from time to time close their doors and go out of business because they do not pay a profit, and others "change hands" because the manager has found that he is making less money operat- ing the theater than he could make doing something else. If the theater would only "operate itself" and pay a profit merely by the condition of its existence, the manager might be a negligible quan- tity in the picture theater, and his personality, his duties, his special training, and the limitations of his business might be neglected in a book of instruction whose scope is to cover the entire motion-picture industry. The "Sick" Motion=Picture Theater. A picture theater is giving service to the citizens of a district of the city, conjointly with several other theaters in the neighborhood. Each gets a share of the people who seek entertainment in the evenings in that portion of the city, but one of them, it will be assumed, gets less than the others, while its cost of operation is about the same. It is only a matter of time until the familiar sign "This Place Has Changed Hands" will be seen, the place is closed for a week to emphasize the change of ownership and to advertise the new opening, a few changes are made in the theater, and business is begun again. From this time on, it gets its full share of the neighborhood's theater traffic, or even more. What is the change? The only fundamental change is the manager. The new manager has brought with him either a knowl- edge of the motion-picture theater business, or an ability to learn the business while nmning his theater. The new manager under- Cop'jrigfil, 1011, by American School of Correspondence. 165 2 THE MOTION PICTURE stands from experience or study, or is able to learn and understand, not only his theater itself, but the people, his people, his patrons who come to his theater. They are his people, for he makes them his. He studies them, learns them, pleases them, and gets their money. Several instances of change of o^\Tiership have been studied especially for the purpose of setting forth the obsers^ations in this book in order that theater managers might profit by them. Change of Management (1). There were three theaters in the same city block, with no other theaters within three city blocks in either direction. The difference in traffic among the theaters in the block was easily noticeable to a motion-picture scout who gave the following two reasons why one of the theaters got less business than its proper share. First, it was the oldest of the three and had the least attractive front, each of the later houses having been de- signed to surpass the older house in outside attractiveness. Second, it was at the distant end of the block from a busy cross-street, so that the larger number of people coming to that block reached the other two theaters first, and could reach the oldest theater only by passing the other two. When the place "changed hands" — an event which came to pass just after the midwinter holidays — the only new element in the theater was the new manager. The place was not even closed for spectacular effect of an "opening night." The new manager, how- ever, was noticed at once. He took upon himself the duties of usher in his theater, and made it a point to stand at the exit door as the patrons who had seen the show came out. If a patron chanced to glance at liim, the glance was met with a smile and a remark, "Call again," or "Good night," or "Did you Hke the show?" or, apologetic- ally, "We are not so crowded except on Saturday nights." He was studying his people as they came out of the theater; he learned them, and they learned to know him and came to expect him to be there. Many of them learned to express praise of a good program which had pleased them particularly, while others by such questions as "\Mien are you going to have another Biography" or a compHment upon any specific film picture, told him just what pictures were pleas- ing his people. He began to put out signs of "Good Selig Tonight" and "Repeated by Request," from time to time, and gained for his theater its just share of the business of the block. 166 MOTION-PICTURE THEATER 3 Under one manager, this theater failed; under another manager the same theater, unchanged except as to manager, succeeded. The pay roll was the same, the quality of film about the same, the projection about the same;- but the manager tried to learn what films would please his people, then obtained that class of subject and from popular factories, and advertised in front of his theater in the par- ticular manner which he found best to attract his passers-by. Change of Management (£). Of three theaters in two adjacent blocks in a city, one had a front of really artistic design in mission style, finished in the dark stain familiar in mission furniture. This place "changed hands" during the summer. The new manager painted that mission finish a pure white, just like the other two theaters, his competitors. A handsome wall sign at the entrance, containing the announcement of the films, and decorated with minia- ture electric lights, completed the only changes noticeable as im- provements. The "Happy Hour" always had had as good a program as its competitors in the next block, but from this time on it had also just as good a patronage as they. Change of Management (3). A small "store front" theater in a large city was located on a cross-street near the principal retail business street of the city. The owner and manager lost money all through his lease of a year and at the end of the year was glad to sell his fittings at a sacrifice to relieve himself of the burden of removing them to vacate the building for the owner. The purchaser was an experienced motion-picture theater man, nmning two theaters on other streets in the same city. He studied the location (before purchasing) and saw that the situation was peculiar. Because the theater was located on a side street, the crowds of shoppers did not pass its door. Just around the corner, on the main business street for shoppers, were two other picture theaters, taking the trade of the shoppers and leaving the side street theater almost deserted. The experienced theater man saw that this theater location did not have an equal chance to obtain the patronage of the shoppers, but he conceived the idea that there must exist a class of people other than empty-headed shoppers strolling into the first open theater door, and he decided to buy the place, thoroughly renovate it, put in a sloping floor, and make an appeal to a special class of patrons by offering a special class of program. 167 4 THE MOTION PICTURE The old show had been running a program of two reels of film, a new reel and a holdover each day; one song illustrated with lantern slides and changed twice a week, the singer being the pianist; and one vaudeville act. This program was given for five cents. The new manager reduced the size of the picture screen, thereby giving a brighter picture and reducing the jiggle of the picture while still using the same projecting machine. Then the vaudeville act was eliminated and a really good singer was employed. The picture films were changed to a program of "daily change" of the two reels without holdover — for this manager hoped to build up some patron- age with office and store people who would come every day, either noon or evening. To this end, his song was changed every day. This gave him a complete change, both pictures and song, every day, with a short program of only about forty to forty-five minutes, but with the quality at the very top, particularly in the matter of the music. The result was unqualified success, and profit. The difference lay in the training of the manager. The first manager did not under- stand his environment thoroughly, and tried to run a do\\Tito\STi theater for shoppers on a street where there were no shoppers; the new manager recognized this limitation of location and did not strive to fight against it, but instead reasoned that there must exist in that section a clientele de luxe, a class of busy people with an inclination for good music, and who would come every day for a short program of high quality. His success with the theater formerly a failure has proved his wisdom. Change of Management (4). This theater was one of two, about a block apart, on a business street through a residence dis- trict of a city. It was run by a man who owned the store building and who, lacking a tenant, thought 'it only necessary to put in a theater front and a picture screen and hire an operator and a film service. He did not make his rental value. A young man living in the neighborhood and working downtown flu ring the dav offered to take the management of the theater, which was open evenings only. This young man had no experience whatever as manager, but studied the traffic of the neighboring picture show close enough to see that the only difference between the two shows was the quality of the films and projection. He took the management of the house, 168 MOTION-PICTURE THEATER 5 changed his fihn service, hired a good projection operator — thereby increasing the running expenses— put out a "changed hands" sign to induce the people to make a trial visit, advertised a special program with hand-bills every week, and got his share of the trade from the first week. In this case, the first manager made a failure because he did not study his own theater to find out what was the matter with it. The second manager made a success, because he studied the two theaters comparatively to learn wherein the one which he thought of taking was inferior to the competitor, knowing that it was necessary only to equal his competitor to obtain his half of the traffic, and knowing — from a head count and an expense sheet — that half the traffic in his theater would pay him a profit. Change of Management (5). This case was pure economy in pay roll. One man started a store-front theater and quit before the end of the first winter. The second winter, another man started in the same store, ran it for two winters, and continues to operate it. This picture show is isolated, being in a small town, the only show in the town. The man who ran this show for the first winter knew notliing of the motion-picture business. He furnished a store room with screen and chairs, a piano and a projection machine, hired a pianist, an operator, and a film service, and started the show, act- ing himself as doorkeeper. The show ran evenings only, and paid no profit. The owner concluded that the town was too small to support a motion-picture theater, and closed the house. The second manager, who ran the theater the second year, was a projection operator. He did not take in any more nickels than the first manager, but he paid less money to his pianist, he got his film ser\dce at a lower figure because he knew what he could afford and did not pay more than it was worth, and, being the pro- jection operator himself, he did not have that expense to deduct from the receipts before calculating his own personal profits from the show business. The net profits to him were such as enabled him to nm the show year after year, and to prove that the to\vn would support a motion-picture theater when the theater was run by a manager who understood the limitations of his field and governed his program and his expense sheet accordingly. Art of the Manager. These illustrations of theaters which have 169 6 THE MOTION PICTURE failed under one manager and then have succeeded under another, every one with only some small difFerence in paint, or program, or pay roll, are given to illustrate the statement that in many if not nearlv all cases the eleinent of success or failure lies with the manager. Every one of the instances show merely that the new manager adapted his theater to the conditions wliich he found existing as limitations upon the theater when he took charge of it. In the example (1), the new manager decided to make his theater different from his competitors by learning the particular things which would please his people and by giving them a personal courteous attention. He won success. In the example (2), the new manager decided that his theater was as good as his competitor's except that it had a sober front, almost repellent to the joy seeker. He changed the color of the front, and won success by eliminating his theater's handicap. In the example (3), the new manager decided that an ordinary theater could not be run successfully in that location, so he tried an extraordinary program, and won success. In the example (4), the new manager decided that his theater had only one handicap over his competitor, the quality of films and projection. He removed this fault, and won success. In the example (5), the new manager saw that the expense could be reduced even though the receipts could not be increased, and his profit lay in the difference. Notice that he did not give a poorer program, but gave the same quantity and quality program at a smaller expense. In (2) and (4), the new manager found a single feature in which his theater was behind his competitors; he brought that feature up to his competitors and won his share of the business. In (1), in (3), and in (5), the location of the theater was not good, but each of the managers found a different solution; in (5), it was simple economy; in (1), it was personal attention to the likes and dislikes of his patrons; in (3), it was a Napoleonic stroke of generalship. Reviving a "Sick" Picture Theater. There is only one symptom which attracts attention to the disease of the theater, and that is the lack of satisfactory net profit. This symptom may be due to either of two diseases .-/r.^/, that the income is not large enough; and second. 170 SCENE FROM PHOTOPLAY, "THE LAST APPEAL" Courtesy of Independent Moving Pictures Co., Xeic York MOTION-PICTURE THEATER 7 that the expense is too large. In example (5), the new manager did not think the income could be increased, but he reduced the expense. In examples (1), (2), and (3), the new manager did not decrease the expense, but by his skill he increased the income. In example (4), the new manager found both income and expense too low, and increased both, increasing the income more than the expense. The "sick" picture theater must be studied particularly with reference to its competition and its location. Then the traffic of the community must be studied to learn whether there is sufficient traffic to support the theater. The question of traffic may be studied in two phases: first, whether there is enough to support the "sick" theater if it were to get its proportion of the total; and second, whether it is necessary or advisable to try to surpass competition and secure for the "sick" theater more than its proportion. The second propo- sition is a case for a doctor of experience. Competition. Study every point of difference which can be found between the theater in question and its competitor or competitors: The color of the front; the decorations of the front; the announcement signs for number, attractiveness, and general desirability; the poster service used for the films; the style of ticket window; the courtesy of the cashier; the method of taking the tickets at the door and the courtesy of the doorkeeper; the seat arrangement; the width of aisles and the confusion or convenience of incoming and outgoing patrons when the place is handling a crowd; the comfort of the seats, their style, their width, and the space between the rows, whether cramped or liberal to permit passing an occupied seat; the number of seats; the decoration of the walls; the illumination during the pictures and during the intermissions; the quality of the films, w^hether new or old and whether clean or dirty or scratchy; the quality of the pro- jection, whether dim or brilHant, whether steady in light or full of flicker, whether steady in position or full of jumps and jiggles on the screen, and whether the whole picture on the screen rises and falls with a wave-like motion; the quality of the song slides and their projection; the quality of the singer; the music or entertainment during intermissions in the program ; the character of the vaudeville, and whether it suits the audience or displeases them, being endured only for the remainder of the program; the frequency of change of program, pictures, songs, and vaudeville. 171 8 THE MOTION PICTURE ^^^len a point of difference is found, study it to see whether the difference is to the advantage of the theater under study or whether it is to the advantage of the competitor. Then decide whether any change should be made in the theater studied. The result of tliis study should determine whether it is possible at a reasonable expense to bring the theater studied up to equaUty with its neighbors, and the study should permit the making of an expense sheet for running the theater in equahty wath its neighbors. The new expense sheet may be smaller or larger than the old; that is immaterial, for the question is: "What will be the expense of making this theater equal to its neighbors or competitors that it may divide the trade with them?" Traffic. An actual "head count" of the patronage of the neighbor- ing or competing theaters must be made, and a count of the number of people "held out" during the heavier hours of traffic, if such occurs. Add the total of all admissions for the theater studied and its com- petitors, and divide by the number of theaters for the hours of lighter traffic and divide by the number of seats in the capacity of the houses for the hours of heavier traffic when patrons are being held 'out at the door. This will give the revenue to be expected in the theater studied if it were brought up to quaUty with its competitors. Income vs. Expense. The two amounts thus obtained — the income from the ticket w^indow and the expense account for equaling competition — will give the profit of the theater without consideration for side lines of profit. The ticket-window profit may be increased by a judicious use of side lines for profit, unless the matter of such devices has been abused and thus brought into disrepute in the neighborhood. The side lines which may be considered are: (-/) paid adver- tising on a drop curtain, displayed during intermissions; (2) paid advertising sUdes for the stereopticon ; (5) paid advertising space on printed programs handed to the patrons either on entering or leaving the theater; (4) paid advertising on hand-bills containing theater announcements and distributed through the neighborhood; (5) sales of candy in the theater during the intermissions ; (6) control or co-operation of a confectionery and refreshment business adjacent to the theater; (7) automatic slot vending machines. Managing a Theater for Profit. Continuous study of the theater, 172 MOTION-PICTURE THEATER 9 day by day and week by week, comparing it with its competitors and comparing it with other theaters at a distance but similarly located, similarly surrounded, and similarly equipped, will enable the manager to determine just what his theater ought to do in the way of gross receipts, expense, and net profits. This gives him a theoretical result which should be attained by his account books. If his books do not show the amount of profit, and from the different sources, which his study shows, he should study his theater as a "sick theater" and strive to learn why he is not doing as well as his competitors, or as well as some other theater operated by another manager under comparatively the same conditions. A study of other theaters, near and far, a study of the technical papers, and a study of the advertising and educational matter constantly sent out by manufacturers in the motion-picture industry, films, machines, accessories, and sundries, will give the manager a correct idea of what his theater should accomplish. Then he may study his own house to learn whether it accomplishes what it should, and if not, he may learn by still further study what is lacking that prevents it from attaining daily its just deserts and its maximum profits. STARTING A THEATER The first detail is to choose a location, then to decide how ex- tensive an investment the location will justify because of its prospective patronage. After that, the building and operating of the theater becomes routine detail, the theater succeeding or failing according to the ability of the manager, his attention to the details of the theater and its patronage, and his ability to learn and understand the salient facts in his studies. Selecting a Location. Among Competitors. In this case, the proposed location may be studied as though the site were already occupied with a "sick theater." The traffic upon the existing theaters may be tallied up and expressed in dollars per week; then a reason- able increase may be figured, for a new theater added to the ones already existing will increase the total of the traffic. This total may be divided to learn how much money will be taken at the ticket window of the proposed new house. Side lines for profit then are studied and added, the total income and the total expense are ob- 173 10 THE MOTION PICTURE tained and compared, and the answer is obtained to the question: How much will another theater in this locality pay in profits? This study may be made upon the basis of another small store- front theater competing with one or two already established, or it may be made upon the basis of constructing a larger theater. If a larger theater is to be compared with a store-front competitor, the total traflBc may be increased largely, say doubled, for the larger, more pretentious house will draw traffic over a larger area, for a greater distance both ways on the street, and then in turn will take a larger share as its proportion of the total, particularly in view of larger seating capacity on the rush evenings when all houses are holding the patrons out for want of seating capacity. Neiv Territory. The only difference is that the traffic to be ex- pected is more indefinite in calculation. It may be predicted very closely by a "head count" of the people passing a possible location. The count should be made every evening for a week, or during all such hours of the week as the theater would be open for business. In the absence of other data, this number may be divided by ten to obtain the number of nickels which may be expected, or one-half cent for each person passing the possible theater. Towns vary in this respect. To obtain the proper figure for the town in which the possible theater is being studied, go to other theaters in the town, count for a few evenings the number of people passing the theater and the number of people passing into the theater, and learn whether the theater gets one out of eight, or one out of twelve, or one out of twenty who pass the door. To the casual mind, the following law may seem without reason, but it will hold true: The proportio7i of people who pass into an ordinary picture theater to the people who pass by will be about the same in all parts of the same city, and the patronage of a theater in open territory may be predicted from a count of passers at the site where it is proposed to start the theater. Having thus by "head count" obtained a figure for the ticket window receipts, the expenditure for establishing the theater, and the pay roll for operating it may be determined in advance, and a theater may be built in that location which will pay a reasonable profit on its investment and running expenses — in short, a success- ful theater may be established, because it will be established in har- mony with the possibilities of its location and environment. 174 MOTION-PICTURE THEATER 11 A person looking for a theater location will find many "possible" places where he might rent or build and start his theater. All of these, or at least several of the more promising of them, should be studied carefully and in detail, making up an income and expense acco\mt for each of the locations; then the best may be selected and the theater started. Small Town. This is a case for study, not so much to determine the place in the town where the theater should be located, but to determine whether the town itself is a suitable location for a theater, whether it will support a theater and how much of an investment and pay roll will be justified. The "head count" for a town so small that only one theater is possible may be taken from the census reports. Any town of 1,000 people will support a motion-picture theater if it is nm by the right man and in the right way. It is found that a "one theater" town will pay weekly at the ticket window from two and one-half to five cents per capita on its census population. A town of 1,000 people will yield from $25 to $50 per week on a show running six nights per week and Saturday afternoon or whatever day of the week the coun- try people use for market day, usually Saturday, but not always. The gross revenue of the small town being determined by mul- tiplying the census population by a reasonable amount to be ex- pected, say three and one-half or four cents per week, it remains for the prospective theater manager and owner to decide whether he can bring his expense sheet sufficiently below the gross receipts to leave an acceptable profit for his time and whether with such an expense sheet he can give an acceptable show which will continue to bring the money after the first few weeks, when the novelty of the theater has worn away. The manager must make himself thoroughly familiar with any city ordinances regulating the operation of motion-picture theaters. Even small towns are having such laws enacted. Financing. For the man who believes that he can make money in managing a picture theater, whether he has experience in the picture theater business or not, yet who has not the necessary funds for starting it, there occurs the problem of securing the money, and upon such terms as will yield him a profit and not pass all the profits to the capitalist who furnishes the money and does no work. 175 12 THE MOTION PICTURE For a small enterprise, which will not require more than, say S2,000, with anticipated profits (excluding manager) of S50 to $75 per week, the manager and promoter may profitably arrange to "spUt the profits" with the capitalist. This will yield the manager a revenue of S25 to §37.50 per week if he can nm the theater accord- ing to his expectations, while the capitalist, who is sole owner of the theater under the agreernent, will receive a liberal return on his in- vestment, even allowing for depreciation of the theater fittings. For a larger enterprise involving much more capital the capitahst may insist upon an unequal division of profits, because the anticipated salarv' for the manager and promoter would look large. In such an instance, the manager should insist upon a fixed salary for himself carried as a part of the expense pay roll of the theater; and in addi- tion an unequal dix-ision of the net profits, giving the capitalist the greater portion. For any enterprise where more than one man puts up any money, a form of stock company or partnership agreement should be drawn up and signed by all. This cannot be much more than informal unless placed in the hands of an attomey-at-law for proper form, but in any event it should be a signed agreement. In such a financing plan, the manager operating the theater will receive a salary as a theater expense, and all profits will be di^•ided by the partners or stockholders in proportion to the amounts of money each of them furnished. A share of the net profits is provided for the manager and promoter by giving him a share in the ownership which he earns by his work in organizing the company instead of by papng cash. This may be one-tenth to one-half stock interest or ownership. A Store=Front City Theater Building. A vacant business house having been selected both for location and for size, the process of con- verting it into a motion-picture theater is to remove the glass front and framing for the door and window, to replace it with a closed front a few feet back from the sidewalk fine into which are built the ticket seller's booth and the entrance and exit doors and on the inside of which is built the projection operator's booth. At the inner end of the room a muslin screen about 3 by 4 yards is stretched. The room is filled with rows of chairs, either kitchen chairs or opera chairs, as the expense justified by the location will permit, and a piano is placed near the picture screen. 176 MOTION-PICTURE THEATER 13 Floor Plan. A few general rules which may be followed in floor- plan construction are given herewith; aside from these a large varia- tion in floor plan is possible. The projecting machine should be at one end of the room and the picture screen at the other end, both being so high above the floor that the rays of light from the projecting machine to the lower edge of the screen will not be interrupted by patrons passing dowm the aisle. The front of the room must be closed against the lights of the street, even when a patron is entering. The operator's room mv^t be laid out with reference to comfort and convenience, 6 feet square is a desirable smaller limit. The floor space, if limited, must be laid oid to seat as many people 05 possible, up to the number which the traffic study will require. 1- := I I I : : 1 1 ^ i ? :iii:i::iz !x> 1 ^ 1 lUJ LJ LjJ ID LJ a_J UJ LU lL'^--I r-r/ _ e- _^ ._.___.__ ^ o — — ^ — — — — — _ _ ^ — — — — — ^^^^^^^^ — e'-o'— — J'-O'-^ -#''0' — —I — 6-0' i Fig. 1. Floor Plan for a Small Store -Front Theater The operator's booth must be lined with sheet iron, top, bottom, and sides, with a door having a latch, and with two look-out holes, one for the beam of light from the lenses and another at least a foot square and with the center at the height of the operator's eye, through which the operator may look to see his picture on the screen; these requirements are for protection against flrc. A floor plan which is adaptable to the general requirements of any store-front theater is given in Fig. 1. This shows an arrangement for the maximum seating capacity for a store room 22 feet by b^ feet in- side the walls. The seating capacity shown is 192. The front partition of the theater is placed 6 feet back from the sidewalk. The ticket booth extends forward from this partition. A still deeper front is desirable if the floor space can be spared; it gives advertising space; 177 14 THE MOTION PICTURE it gives opportunity for decorative efforts without the expense of decorating the entire front of the business house; it suggests retire- ment in the theater, and when the prospective patron steps off the sidewalk he feels that he is already within the theater, even before he has purchased his admission ticket. The entrance and exit doors in the partition should be double doors. The entrance doors at A should swing both ways, while the exit doors at B should swing outward but not inward. The ticket booth in Fig. 1 is 6 feet by 5 feet inside, with a shelf 1 foot wide across the front for making change. The three glass windows should be made with removable sash in order that screen wire or grille mav be substituted in the warm weather. The operating booth occupying the upper part of the space D is built over the ticket booth upon an elevated platform about 5 by 9 feet in size. As the patrons of the theater are required to pass under this platform it should be built upon a platform about 7 feet from the floor. A stanchion is set from floor to ceiling at E, about 9 feet from the side wall and 5 feet from the partition, and with this stanchion as a corner post a platform is built to cover the space D, then closed in with walls from the platform to the ceiling to form the operating room. ^Yindows for projection and lookout are left in the wall toward the screen J, and another window may be left in the end for ventilation and over the doors A in the partition. Entrance to the operating room is obtained by means of the ladder at F, which extends upward along the wall and through a hole about 30 inches square in the floor of the operating room. Below the operating-room platform, extending from the stanchion E to the wall, a screen G should be placed to prevent the light of the street from reaching the screen when the doors A are open; this may be a curtain hung from the edge of the operator's booth. The doorkeeper stands at the post marked H. A movable chain or bar is provided to extend from the stanchion E to the wall of the ticket booth to close the passage at the dotted line I. This enables the doorkeeper to hold back patrons who come so near the close of a picture or act that they would be interfered with by patrons passing out, or by patrons for whom there is no seat.- The piano may be at K, either automatic or manual. The screen J is shown at one side of the center; this has two advantages in the 178 MOTION-PICTURE THEATER 15 floor plan as shown. It gives more room for the piano and singer at the side of the screen, and it brings the center of the screen nearer to the direct line from the projection machine at the end I of the operating room at D. Another method of building an operating room is to build it over the cashier's booth, extending through the partition and pro- jecting into the theater room as far as the stanchion E. Set two stanchions like E and build the platform to the ceiling, placing the ladder F beside the short wall of the cashier ticket seller's booth, just inside the entrance door. The projecting machine will stand against the wall of the operating room at the exit-door side, and the projection and look-out windows should be placed in the front wall accordingly. A space of 6 or 8 feet between the front chairs and the picture screen should be allowed, as the pictures cannot be viewed at a very close range. If the seats marked X are left out, the added con- venience to patrons in passing out of the theater may more than compensate for the decreased seating capacity. Lighting Methods. Ceiling lights, say a sixteen-candle-power lamp for each 50 square feet of floor, should burn during the inter- missions. Shaded wall lamps, say an eight-candle-power lamp every 10 or 12 feet along each wall, should burn all the time, includ- ing the time during the pictures. The wall lamps should be so shaded that the light will not shine upon the picture screen nor upon the eyes of the audience. The term "daylight-theater" is used to designate a theater in which the auditorium lights are not turned off during the projection of the pictures. This result is attained by hanging the ceiling lamps in sixty-degree conical shades, or the equivalent in ornamental shades, so that the light from each ceiling lamp covers a circle on the floor under the lamp but does not shine on the picture screen, nor does it shine back toward the entrance into the eyes of the seated patrons. The lamps thus shaded must be distributed over the theater ceiling, and not grouped, as then the desired eft'ect would be lost. Low-Cost Store Front. To build for the lowest cost of starting operation, in a location where only the minimum expense is justified or where only the minimum expense is desired, the front partition may be modeled upon the style shown in Fig. 2. This is all simple 179 16 THE MOTION PICTURE carpenter work and painter work. The complete change in the store room, ready for chairs, piano, wiring and projecting machine, should not exceed S150; 200 chairs of the kitchen variety at $100; electric lamps and \^aring at $100; a projecting machine at $165; and a rented piano — the total expense amounting to about $500. With a small additional amount for supplies and initial advertising expense, the manager will be able to open his doors to the pubhc at a total cash expense of not more than $600, and no debts. Only country towns of small size without competition, or un- rig. 2. A Simple Front Design for a Store-Front Theater occupied or non-competitive city territory, will permit a successful theater with so simple an estabUshment. Such a theater could be established upon a prospective ticket sale of $110 to $150 per week, since the return for the manager's labor and a return for the cash invested must be earned in addition to the expense sheet given below. The item of "Supplies" includes tickets, carbons, condensers, lamp renewals, machine repair parts etc., and piano tuning, including in this case also the rent of the piano. This is a fair expense account for a small city house, even though at 180 MOTION-PICTURE THEATER 17 a much larger initial cost, where competition does not compel a larger expense, yet where the patrons constantly are comparing this residence district theater with the more pretentious down-town motion-picture theaters. With such distant competition for comparison, it is neces- sary to maintain a quality of picture projection and music which will stand the comparison, if the theater is to be a continued business with profits. The cost of operating this theater, evenings only — for it would be either in a small town or in a residence territory of a city — for a program of two reels of film and a song, would be, by the week, about as follows : % Rent and heat $ 10 . 00 Electricity 5.00 Film 20.00 Song Slides 2 .00 Supplies 13.00 Operator 15.00 Cashier 3.00 Doorkeeper 5.00 Pianist 5.00 Singer • 5.00 Weekly Expense $ 83.00 In a non-competitive small city, not only will the rent be lower, but the wage rate will be lower throughout. Elaborate Store-Front. The floor plan will be the same in this case as in Fig. 1, the difference being found in the quality and appear- ance of the elements going to make up the theater. A decorative front such as is illustrated in Fig. 3 will cost $500 to $2,000 for the front partition complete with operating room and cashier's booth, including all the decoration in front of the partition. Another $500 or more will be needed to raise the floor and to install 200 opera chairs at $1.20 to $1.60 each. The inside decorations and the picture screen of modern type will raise the expense $200 to $300 at least. The total expense need not exceed $6,000; with any pre- tensions toward beauty and luxury, it cannot be kept below $2,000. For designing and building the front, a firm in the special work should be employed, unless the manager who is starting the theater is of long experience and knows exactly what he wants. The large number of such theaters which have been built has developed con- 181 18 THE :^IOTIOX PICTURE struction firms and workmen particularly skilled in such work, whose very presence on the job will insure that refinement and perfection of detail which the manager desires but which the inexperienced Fig. 3. A Decorative Front Design for Store-Front Theater. manager employing inexperienced workmen is Hkely to overlook, leaving his house inferior to those of his competitors. In selecting or approving a plan by a professional designer, the manager should see that the cashier's booth is large enough for com- fort all the year round and that the projection operator's booth is large 182 MOTION-PICTURE THEATER 19 enough for two operators and two projecting machines. Not only may competition enforce the employment of two operators, but it will be found positive economy to give the operator an assistant during the rush hours of Saturday night. In a house of this class, a manager's control panel and signal system should be installed at the door where the ticket-taker stands, that he may signal the operator to begin projection, and may ring for the singer, etc., controlling the conduct of the program par- ticularly during the rush hours when the passing of numbers cf people in or out may delay the beginning of the next picture. The program selected — by this term "program" is included the cjuality as well as quantity of pictures, song, music, and vaude- ville — must follow the custom of the city in which the theater is located, if the certainty of a proper division of patronage is desired. A departure from the custom of the city may result in a larger suc- cess, or may result in failure. Such a departure was made in the theater discussed in "Change of Management (3)," and serves as an example. A specimen expense sheet of a high-class store-front picture theater is here given. WEEKLY EXPENSE SHEET Rent, of complete theater, week $ 40.00 Film rent, three reels daily change.. . 50.00 Carbons 1 . 00 Pianist 15.00 Violinist 10.00 Drummer 12 .00 Usher 2.50 Electricity 18 .00 Song Slides 2.00 Cashier 5.00 Singer 18.00 License 4 . 00 Projection operator 18 .00 Porter 4.00 Ticket taker 5.00 General Expense 10 .00 Total weekly expense, not including manager $214 . 50 Receipts, average, six nights $240, Sunday $100; total weekly receipts, average. 183 20 THE MOTION PICTURE Specimen Expense Sheet of a High-Closfi Store-Front Picture Theater. The figures given above are the actual expense sheet of a house of this class in a residence district of Chicago. The rent item is the amount paid per week, making a rental of $173 per month or $2,080 per year, but this is for the house equipped with chairs and projecting machine, so that the expense sheet is carrying the item of depreciation of investment as a part of the rent item. The cost of opening this house for business was in the neighborhood of $3,000. This particular theater charges a five-cent admission seven days in the week. The seating capacity is 300. A one-hour program is given at 7, 8, 9, and 10 P.M. on week days and at 2, 3, 4, 5, 6, 7, 8, 9, 10 p.m. on Sundays — thirty-three shows per week, three reels and a song in each program. The film is one reel third-run, one reel not more than ten days old, and one reel not more than three months old, daily change, for which $50 per week is paid. Two different songs are given, alternating in every other program, with one singer. Music is furnished by an orchestra of three. The item of "Sundry Expense" includes tickets, coal, condensers, poster service, machine repairs, lamp renewals, piano tuning, etc. In this theater, the manager takes profits rather than a salary. He has no capital invested, but in the $40 per week rent he is paying a return to the capitalist for the investment. Slo'ping Floor. This method of floor construction raises the eyes of patrons in the back seats above the heads in the front rows, givino- the patrons at the back of the house a better view of the pic- ture screen or stage. The sloping-floor construction is necessary in houses classing above the simplest of store-front theaters. It is a good bid for business to equal or excel a competitor, because it gives a greater comfort to the patron, and makes the picture theater resemble more closely the larger, more pretentious city houses. A side view of a store-front theater with one wall removed is shown in Fig. 4. This shows the sloping floor, and one method of constructing it for store-front houses. AMiere the building is erected specially for theater purposes, even though it be a part of a business block and a store-front in appearance, this plan is easily followed, but where an old building is remodeled it is necessary to cut the floor joists at the picture screen end if the entrance doors are to be level with the street or sidewalk. A raised floor may be constructed upon the store-room floor by building a few low trestles or "horses" across the house, say 18 inches or 2 feet high at the street partition of the house, and getting lower toward the picture screen. Joists for the inclined floor are laid sloping upon these trestles, and taper to a point at the toe where the new sloping floor meets the old level floor. .The slope may extend 184 MOTION-PICTURE THEATER 21 two-thirds the way to the picture screen, and the front third of the house may be level. Steps may be built between the street level and the raised floor, or the floor may be sloped up from the street line to avoid steps, even carrying a slope into the aisle of the theater. The floor plan arrangement for the street end of the theater of Fig. 1 is suitable for the theater of Fig. 4, or the projection booth may be built over the ticket booth. In the theater of Fig. 4, the requirement for the height of the projection room floor and for the height of the projection window is that the rays of light from the lens to the lower edge of the picture screen should clear the heads of persons standing in the aisle. A comfortable amount of slope for the theater floor is 1 foot in 8. This is the slope shown in Fig. 4. Seats upon a sloping floor must be the "theater seat,'' as shown in end view in Fig. 4; or if chairs the legs must be sawed to make Fig. 4. Theater with Sloping Floor the chair comfortable. \\Tien theater seats are bought, it should be specified that they are for use upon a sloping floor, and they will be furnished accordingly by the manufacturer. The seats between the bottom of the slope and the picture screen are ordered for level floor. Stage. If a stage is to be built, either for vaudeville purposes, or for scenic effect in the theater, the stage floor should be 3 feet above the theater floor in front of the stage. The proscenium arch in such a stage may extend to within 1 foot of a low ceiling, and within 3 feet of each side wall. 185 22 THE MOTION PICTURE If for decorative effect only, the picture screen may be stretched permanently across the opening. The projected picture should be kept a foot or two above the bottom of the screen. If for use for vaudeville, the stage should be 10 or 12 feet deep, with two wings on each side. An interior flat should be at the back and a street scene half-way between the back flat and the drop curtain. The picture screen should be at the front, just behind the drop cur- tain. By "interior flat" is meant a flat painted scene showing the interior of a room. There may be two pairs of wings for the interior scene setting and one pair of wings for the street scene, with flies sufficient to conceal the ceiling from the patrons in the front row of chairs. If the stage is used for vaude^^lle, footlights must be installed, with switch at the ticket-taker's station at the entrance, and the projection operator must be provided with a mask for his stereopticon which will cover the stage opening but not the sides of the arch. Picture Screen. For a screen against a wall, the wall may be painted white, or given a "white finish" coat, such as plasterers use in finishing a wall smooth. Over this white surface, stretch a sheet of thin muslin, with as few seams as possible. Have the seams run horizontally, and tack the musUn all around the edges. A neat and inexpensive finish is obtained by nailing to the wall a frame of wide picture-molding, mitering the corners as though the screen were framed and hung upon the wall. Any wall screen or drop curtain screen may be treated by a coat of paint containing finely divided particles of some glittering sub- stance, such as finely-divided aluminum dust, or finely-powdered glass, or the curtain may be painted with any sticky paint and the metallic dust or powdered glass thrown or blown upon it and, when the sticky paint dries, a glittering surface will remain upon the screen producing what is known as the metal-surfaced screen. These tricks of producing metal surfaces are well known by sign painters. The picture projected upon such a metallic-surfaced screen is more brilliant in its light portions, while retaining all the detail of its darker or shadowy portions. At the same time, the dead white screen may be a matter of personal preference, or where all com- petitors use a metallic surface, the dead white of thin cloth backed by white plaster cleaned from dust occasionally to keep it white, 186 MOTION-PICTURE THEATER 23 and kept free from stains at all times, together with a smaller and brighter picture, may be urged as an advertising point of advantage over the methods of competitors. The mirror screen increases the brilliancy of a picture. Also, it is Hkely to give "haloes" or radiant bright spots to some places of the auditorium if the surfacing is not sufficiently dense. The cost runs to $300 or $400. The theoretical mirror screen as announced to the public consists of a sheet of plate glass, the size of the projected picture; this glass is silvered upon the back and ground to a smooth ground- glass finish upon the front surface. The ground-glass surface gives a good screen surface for projection, even if not backed, being equiva- lent to a surface of finely-powdered glass, but all light which passes through the ground-glass surface is reflected by the mirror back to the surface again and through it to the spectators in the theater. The result is a large increase in brilliancy in the picture projected with the same conditions of lamp and lenses. ^lirror screens are made also by painting the surface of a large mirror with a frosting surface, such as a thin mixture of English "whiting" with water and a little glue. A substitute for the real mirror screen is a mirror over which is stretched a sheet of tliin muslin. The muslin should be seamless — muslin sheeting 8 feet wide may be obtained in the market — or the seams must be made by setting the two selvedged edges against each other and whipping them together with a very fine stitch without lapping the fabric. \Miere a lap seam is used, the mirror beliind the fabric shows the seam so very plainly that it becomes decidedly objectionable. The thin fabric screen backed by a mirror is an improvement upon the fabric screen backed by a white wall. The cheapness of such an arrangement is based on the fact that the mirror used to back such a fabric screen may be made economically of small sheets of silvered glass rather than of a single large sheet, the small sheets being set snugly together without bevel edges and without mounting, that the lines of joining may not be noticed by the patrons. Small clamps may hold the mirrors to a supporting wall or vertical plat- form, care being taken to make the entire mirror surface fiat. AMiere, because of clearing the stage for vaudeville acts, it is necessary to roll the picture screen, the screen must be made of 187 24 THE MOTION PICTURE opaque white fabric, and fitted with a heavy roller to stretch it when rolled down, or tackle must be used at the bottom to stretch it. A waving curtain produces a very objectionable effect in the picture. Metallic surfaces have been used on roller 'picture screem. Great care must be used to avoid wrinkles when the metallic surface is used, for the small wrinkles are much emphasized by the reflecting nature of the sparkling surface. Special Buildings. A theater building having a 50-foot front and seating five hundred or more people may be built at a cost aside from the lot of S10,000 to .$20,000, according to design and location. Such houses usually are run to a longer program than an hour of pictures, being vaudeville houses rather than simple picture houses. The principles of operating such a house do not vary from those of the smaller picture theaters. The same tact, skill, and ability to learn from experience and from observation of other houses of the class are required of the manager. The same balancing of gross income against expense, and the same possibilities of side lines for additional profits, exist. A house of this size in the residence districts usually runs a vaude- ville program and charges an admission of ten cents or more. Example of Special Theater Building. The class of theater occupy- ing a specially constructed building, in the residence districts of Chicago, is well represented by the particular theater from which the following facts are taken : The lot, 50 by 125 feet, upon which the building is erected, was estimated in value at $10,000; and the erection of the building and its equipment ready for the public, cost $15,000, making a total expense in the building itself of $25,000. For this investment the owner takes a rental of $5,200 per year from the receipts of the theater. This item is considered an item of rent in the theater expense sheet, and is paid weekly at the rate of $100 per week, as rent. The program consists of four acts of vaudeville, two reels of film, and a song. There is an orchestra of four pieces. The program lasts about an hour and a half to an hour and three-quarters. The program is given twice each night, once on Wednesday afternoon, once on Satm-day afternoon, and twice on Sunday afternoon; eighteen performances per week, of which four are on Sunday. In case of a long vaudeville program, the song is omitted. The house contains 800 seats, of which 600 are on the main floor and 200 on the balcony. Of these, 350 seats are sold at twenty cents and 450 at ten cents; the total value of a full house is $115. An average evening in fair weather is a house and a half for the two performances. Of the twenty-cent seats, fifty are the front rows of the balcony; this raises the tone of the balcony as a seat location and helps to sell the house out when nearly full. The film service is one reel ten days old and one reel not more than three 188 MOTION-PICTURE THEATER 25 months old, change twice a week; for this service, the price paid is $20 per week. The entire program, vaudeville and film and song, is changed twice each week. The illustrated song slides, when used, and the singer as well, are fur- nished free by the music publishers for the advertising value. WEEKLY EXPENSE OP A SMALL VAUDEVILLE THEATER Rent, per week $100 .00 Film service, per week 20 .00 Carbons 1 .00 Orchestra of four pieces, per week .... 91 .00 Two ushers '. 5 . 00 One fire guard 7 .00 One stage manager 20 . 00 One stage helper 7 .00 Electricity, per week 30 .00 Cashier 7.00 License 4 . 00 Poster title ser\ace 5 . 00 Projection operator 18.00 Vaudeville, average weekly 500.00 Porter and watchman 12 .00 Ticket taker 8.00 Sundry small expenses, average per week 25.00 Weekly expense sheet $860 .00 Average receipts for six days, fourteen performances, $900.00; for Sunday, four performances, $315. Average weekly receipts, $1,215. Large Exclusive Picture House. Only in the shopping district of a city can a sufficient number of patrons be found to fill a large house repeatedly for short programs. The data given here for such a theater is taken from a theater on the busiest retail business street of one of the largest cities of the United States, a theater representative of the highest class of motion-picture theater. The house is open fourteen hours per day, seven days each week, from 9 a. m. until 11 p. m. The program is three reels of film (or three pictures, not necessarily each a full reel) and two illustrated songs. The film is all first run, changing the three reels three times each week, without holdovers, but a good film picture frequently v/ill be repeated a few weeks later, with the advertising sign, "Repeated by request." The songs are changed weekly. Two 189 26 THE MOTION PICTURE singers are employed for the two songs of each program, one male voice and one female voice. Three projection operators, working at the same time in the operating room, put on the program. Two of these operators have motion-picture projecting machines, while the third operator pro- jects notliing but stereopticon slides, both announcement slides and song slides, attending also to the illumination of the auditorium dur- ing the intermission. The order of the program is as follows: The show starts with a few announcement slides; then the first motion-picture operator puts on the first film picture. As the end of the film picture approaches the stereopticon operator stands ready and projects the song title upon the tailpiece of the film, the pianist opens the introduction to the song as the title appears and the song follows without a second of lost time. At the close of the song, the second motion-picture operator stands ready and begins projection at a signal from the stereopticon operator, the last slide of the song dissolving into the title of the next film picture. In the same manner the screen con- tinues without interruption of projection into the second song and then into the third film picture by the first projection operator. At the close of the third film picture the lights are turned on, the crowd is allowed a few minutes for passing out and in, the candy man makes a trip, and the program is repeated. The house is "dark ' about fifty minutes for the program of three pictures and two songs, and is "light" for about five minutes for the intermission. For the ordinary day, fifteen performances are given in the fourteen hours. On Saturday, the busy day, an extra performance is given, making sixteen in all. The house, equipped fully for the operation of the theater, represents an invested capital of $100,000. The building was com- pletely remodeled for the theater, under lease to the theater mana- gers. It is not owned by the theater managers, and a rental of $48,000 per year is paid. This includes heating. Figured upon a weekly basis for the weekly expense sheet, this rental is $923 per week. The theater seats seven hundred people. The admission price is ten cents, anywhere in the house, giving a value for a "full house" of $70. The attendance averages about six-tenths of the total capacity 190 IMOTION-PICTURE THEATER 27 — six-tenths of seven hundred seats, filled fifteen times on an average for six days, 6,300 tickets per day for six days and 400 more on Saturday for the extra performance, about 44,500 tickets per week, or $4,450 weekly receipts at the ticket window. On many Saturdays — the busy day with sixteen performances — the ticket sale reaches nearly 10,000, or $1,000. The theater is operated by two sets of employes, called the day force and the night force, each working seven hours continuously. The day force works from 9 a.m. until 4 p.m., the night force then coming on and working until 1 1 P. m. Thirty-five employes are on the pay roll of the theater itself, aside from the manager and his clerical help. The orchestra comprises pianist and drummer, and a "sound effect" man for adding something of realism to the pictures by supply- ing some of the sounds attendant in nature upon the scene represented. Weekly Expense. The item of rent is a matter fixed by contract with the owTier of the building. It appears high when compared with rental values of theaters of similar seating capacity but located in the residence districts of the city w^here the land values are not so high. In the item of electric current, it must be noted that this theater runs fourteen hours per day, against an average of five hours per day for a residence district theater. The electric lighting and electric signs in front of the theater are profuse, and most of the lamps burn the full fourteen hours per day that the theater is open. The film rental item of SI 26 per week for three reels changed three times a week takes into account the large nimiber of times that each reel is run through the projecting machine. The wear upon the film naturally is greater for the fifteen shows per day which this theater gives than it would be in a residence district show of four performances daily. It is true further that "first run" film is the most e.xpensive run of film for the theater manager to buy, and that all of this theater's film is first run film. The item of "sundry expenses" includes tickets, carbons, lamp renewals, machine repairs and depreciation, piano tuning, painting a large sign three times per week with each change of program, and many minor expenses. In each of the items where the pay roll is involved, it is remembered that the item is doubled to provide for the two forces of employes covered by the list, the day force and the night force. Six projection operators are employed, three for the day force and three for the night force; of each set of three, are two motion operators and one slide operator. A guard in full police uniform is in attendance at the entrance door. A fire guard is required by the rules of the fire department of the city. The orchestra of six employes comprises the two pianists, the two drum- mers, and the two sound artists. 191 28 THE MOTION PICTURE Of the fovir singers, each is required to sing seven or eight times — a day's work. Two are on the day force and two on the night force; each sings once in each show. WEEKLY EXPENSE SHEET Rent and heat, per week $923 .00 • Electricity, per week 200 .00 Film rental 126.00 Song slides 2.00 Sundry expenses, per week 130.00 License 8.00 6 Projection operators 112.00 2 Cashiers 30.00 2 Uniformed police at door 36 . 00 2 Fire guards 28 .00 2 Ticket takers 30 .00 6 Orchestra and soimd effects 210.00 4 Singers 100.00 3 Porters 36.00 8 Ushers 80.00 Manager, per week 40 . 00 Assistant manager, per week 25.00 Stenographer and bookkeeper 15.00 Messenger boy 6 . 00 Telephone 2,00 Office supplies and sundry 6.00 Average weekly expenses $2,145.00 Average weekly receipts, $4,450. Country Theater (1). The theater from which this expense sheet was taken was unsuccessful. The expense seems about a minimum for a theater in which the manager must employ help for all of his ser\^ice, yet the gross receipts of the theater did not justify even this expense. WEEKLY EXPENSE SHEET Rent $ 3.50 Film service, 7 reels weekly 18.00 Express charges 1 .00 Electricity 3.00 Operator 10 .00 Ticket seller 1 . 50 Pianist 3 . 00 Coal (winter expense) 2 .00 Tickets, carbons and sundry 1 .00 Total weekly expense $43.00 192 MOTION-PICTURE THEATER 29 Average weekly receipts, $40. This town had a census population of 1,100 people, giving a probable weekly ticket window income of $27.50 to $55. Country Theater (2). In the same town, under a different manager. The experience of the first theater had showii about what gross income could be expected. The expense account was planned to fall below the anticipated income by enough to leave a profit for the manager. WEEKLY EXPENSE SHEET Rent $ 3.50 Film, eight reels, express paid 12.00 Electricity 3 . 00 Operator Ticket seller 1 .00 Pianist 2 . 50 Coal (winter expense) 2 .00 Tickets, carbons and sundry 1 .00 Newspaper advertisements .50 Total weekly expense $25.50 Average weekly receipts, $45. The commercial run of film satisfied his audience for quality, and age of subject was immaterial, as all were new to his patrons. The eight reels were run as follows: Two on ^Monday night, one new and one holdover on Tuesday night; one new and one holdover Wednesday night; one new and one holdover Thursday night; one new and one holdover Friday night; two new reels and one holdover Saturday afternoon and Saturday evening. This gave a three-reel show on Saturday and prices of ten cents for adults and five cents for children were charged. The manager ran the projecting machine himself, thus avoiding an expenditure for an operator's salary. The ticket seller sold tickets and noted that the patrons dropped them into a ticket box at the door, which box could be seen by the manager from time to time as he chanced to look. The pianist seems the only luxury on the bill of expense. The small advertisement in the local newspaper seems good business judgment. Country Theater (3). In the same town, during the summer. 193 30 THE MOTION PICTURE During this season, the patronage of the country folk is largely with- drawn except on Saturdays. The operation of the picture theater was changed to suit the changed conditions for the summer months. The theater building or room was held over the summer at the uniform rental rate for the following winter's business. The film service was reduced to three reels for the Saturday show, and shows were given only on Saturday afternoon and evening. Admission was five and ten cents, as on Saturdays during the winter. WEEKLY EXPENSE SHEET Rent $ .3.50 Film, three reels express paid 5.00 Electricity 1.00 Ticket seller .25 Pianist .75 Sundry expense .50 Newspaper advertisements 1 .00 Total weekly expense $12 .00 Receipts averaged between $15 and $20 weekly. In addition to the profit of the one day at the theater, the manager had other employment during the week. Country Theater (4). This theater is located in a country town whose census population is but six hundred people. The gross income which might be expected in such a town, according to the rule, would be S15 to $30 per week, and this is based upon a show running six nights and one afternoon per week. WEEKLY EXPENSE SHEET Rent, heat and ticket seller, two days $ 3 .00 Film, five reels, two days 4 . 50 Express charges .35 Expense for acetylene-lamp supplies .30 Sundry expenses 1 .00 Total weekly expense $ 9.15 Average weekly receipts, $14. For an exhibition room, a lodge hall seating about one hundred and twenty-five people was obtained at a price of two nights for $3, including the heating, and a ticket s-eller was furnished as a favor. The item of film, five reels for $4.50, was attained by "splitting the week" with another theater in a neighboring town, which used the five reels during the remainder of the week. 194 MOTION-PICTURE THEATER 31 The total expense of starting this theater was about $60 for a complete projecting outfit with acetylene lamp. Aside from this there was no expense but the curtain for the picture screen. The manager and operator was regularly employed during the day, his show profits, being "velvet." The program given was three reels the first night and two new reels and a selected holdover reel for the second night. The price was five cents. Airdome. This name has been adopted to define a motion- picture theater in the open air. A fenced enclosure is chosen, or a canvas 8 to 10 feet high is erected upon stakes to form an enclosed yard. At one end a projection house or even a projection platform is built; at the other end, a picture screen of usual theater size is erected. Chairs are arranged before the screen as in any motion- picture theater, and the entire conduct of the airdome is quite the same. A platform may be built before the screen for vaudeville. The airdome is for fair weather only. The novel idea seems to please the general public, whether the airdome is operated in a coun- try to^vn or upon a vacant lot in a large city. The illustration, Fig. 5, shows an airdome upon a city lot Fig. 5. The Airdome beside a business house. The lot is divided by the picture screen and the admission gate, the front portion of the enclosure being used as a refreshment park in which the music from the airdome piano or orchestra (if any) is heard, while the rear portion of the lot is the theater itself. OPERATION Studying Audiences. The manager will learn much about his show by watching his patrons as they come out. It is not necessary to inquire what they think of the show Comments will pa.ss among them which may be overheard by the manager and by the casliier 195 32 THE MOTION PICTURE as they pass the ticket window, commenting favorably and un- favorably upon the film pictures which they have seen a few minutes before. In this manner the manager may learn when any particular picture has favorable comment, and may endeavor to have his film exchange supply more of the same class; likewase, when any picture has a flood of unfavorable comment among the theatergoers them- selves, the manager may try to influence his film exchange to avoid sending him that class of subject. The words, "try to influence his film exchange," are chosen carefully to express the true position of the exhibitor, or theater manager, in the matter of obtaining film pictures acceptable to his patrons. The film exchanges as a rule take all the film pictures pro- duced by the particular manufacturers from whom they buy. All of these film reels look alike to the film exchange man, and he would like to send them indiscriminately to his customers, to the exhibitors, or to theater managers. The service the theater manager will get, therefore, w\\\ be "hit or miss" of the film exchange stock of reels unless some influence is used by the manager to govern the classes of pictures furnished him. Film exchanges are notoriously lax in the matter of selecting pictures for particular theaters. If the film service is to be what the manager desires, the deliveries of the film exchange must be watched constantly and carefully. The manager who has learned the tastes of his audience should consider their tastes as a requirement upon him to obtain the pre- ferred classes of pictures from his film exchange. The responsive- ness of the audience in the theater is one barometer of public ap- proval; the attitude and conduct of patrons leaving the theater is another. The ticket sales will be another, but this last is not so quick in its indications of response. AVhen a picture pleases the audience, it may be the specific picture, or it may be the general class to which the picture belongs; in one neighborhood, dramatic and scenic may please more than comic or historical; in another nothing but comics can draw the crowds and send them away smiling. The Program. \Miether vaudeville is advisable and profitable, and whether the song is a drawing card or whether the audience would rather have solid pictures, all may be learned from watching the house during the performance and watching the faces and com- 4 196 MOTION-PICTURE THEATER 33 merits of the patrons as they pass out after seeing the performance. Choice of a program is a great factor where the theater is in a competitive position. There is but httle difference in expense between a three-reel program and two reels and a song. Advertising. A sign at the door of the theater may announce the titles of the films being shown, or may announce merely that motion pictures are being shown. It is customary to announce the titles of the films if the films can be obtained from the film exchange Fig. 6. A Title Poster long enough in advance to prepare the sign, or if posters are delivered with the films. At times it may help business to advertise the name of the maker rather than the name of the film, or to post the announce- ment as to the nature of the picture, "A roaring farce tonight," or "Beautiful colored picture tonight," rather than a title which might not suggest the nature of the film. In all of these details of his an- nouncement boards at the front of the theater, the manager must use his judgment as applied to his patrons. Variation in signs is 197 34 THE MOTION PICTURE advisable; and always bear in mind that the program, the film pic- tures, the song and the music, or vaudeville, if any, if mentioned in the theater-front signs, must justify the sign and fulfil all its promises. Poster Service. Title posters may be obtained from the film exchanges at a very small cost — five cents each is the usual charge — or they may be obtained from companies making a specialty of supplving title posters for films. These come in one-sheet size — the standard title poster size adopted by all film makers— and have something the appearance of the poster of Fig. 6. The charge for a poster service consisting of a weekly shipment of posters for the current films, which the theater manager then holds until he gets the films and ultimately throws away the posters which he has received for which he never got the films, is from $5 to $10 per month. In addition to simple "title posters" containing a stock form of border design (sometimes in color) and the title of the film printed upon it, the film manufacturers publish with each film an attractive colored poster, one-sheet size. A quantity of these are delivered to the film exchange with every film sold, and in turn the film exchange will furnish them to the exhibitor to whom the film is rented. As to the terms upon which the exhibitor may secure these posters, that is a matter individual to the film exchange. Usually they are furnished free to the customers who get the films first, paying the higher prices for the early runs of the film. I^ater users of the film do not get any posters because they are all gone. The "title poster" service is a resource when the manufacturer's more desirable picture posters cannot be obtained. Electric Signs. An electric sign, with a word in letters formed by electric lamps, such as "Theater," "5c Theater," "^Motion," or "Pictures/' or even "5c," can be seen a long way up and down the street. A simple electric sign is illustrated in Fig. 7. This has the words, "Theater 5c," in letters studded with electric lamps. With 4-candle-power lamps taking about 12 watts each, and with electric current at 10 cents per kilowatt, the cost of current for operating this sign four hours in an evening would be about fifty cents. To this may be added cost of lamp renewals, interest, and depreciation on the sign, if so desired. The cost of such a sign is about $50. 198 Fig. 7. A Simple Electric Sign MOTION-PICTURE THEATER 35 Another type of electric sign is shown in Fig. 8, in which the letters are not studded with lamps, but in which the lamps of the sign form the attractive feature. The figure 5c in the middle of the sign is set with lamps, and the zigzag line from the upper right- hand comer to the lower left- hand corner is set with a line of lamps. A sign flasher is con- nected with this sign, lighting the lamps in this order: The zigzag line represents a lightning flash. The first lamp at the top is lighted, then the next, and so on until about eight are lighted, then as each lamp ahead is lighted the lamp earliest lighted of the eight is put out, so that the string of eight lamps seems to move along the zigzag line. This action is very rapid, and the lightning flash crosses the sign very quickly. Then the 5c is lighted for a few seconds, then extinguished for a few seconds, and the light- ning flash is repeated, beginning the next cycle. The flashing of the lamps is done by a drum of contacts run by a small motor. The number of lamps is about the same as in the sign of Fig. 7, and the cost of current is about the same, the lamps burning but a part of the time, and the motor running all the time. The first cost of the sign is much greater. In a simple sign bordered by *: ^ '' Fig. 8. Electric Sign with Flasher lamps, the lamps may be made to "run around" in the same way that the flash crosses the sign of Fig. 8, adding to the attractiveness of an otherwise very plain sign. Announcement Slides. The program of the theater always may be announced by advertising announcement slides. These take the form of "Pictures Changed Daily," "Song Changed Twice a Week," "New Song Tomorrow," "Colored Picture Tomorrow Night," "Special Educational Show for School Children, one hour, beginning at four o'clock Friday," all of which are direct advertising slides, but will not be so considered by the patrons because they pertain to the show. Although they take but a minute or two, they may well be omitted on Saturday night's rush, particularly if so doing will put on one more show in the evening. 199 36 THE MOTION PICTURE "Next show" slides are of doubtful utility, announcing the sub- lects for tomorrow. It is doubtful whether at any time it is advisable to announce the subjects for tomorrow, if competitive theaters are near by, unless the subject is a special one and, therefore, specially advertised. AMien used, the "next show" slides must be prepared by the theater manager or projection operator, from day to day, as the titles are learned ahead. Printed Programs. With "daylight pictures" — the expression is used to mean that the lights of the room are not turned off while the pictures are being shown — a printed program may be given to the patron at the door. The printed program always carries advertising matter, and should be so designed as to advertise the theater properly, as well as to serve its paid advertisers. Newspapers. Advertisements inserted in the newspapers are seldom profitable in the large cities; in the smaller cities, it may be found so; but in the country town, where the newspaper is a weekly and everybody reads all of it, 50c or SI per week is well spent. The simple announcement, with some display line in it, may or may not give the titles. Handbills. In the large city, the theater located in the residence district will find that the handbill will take the place of the newspaper in the small toA\'n, and cost but little more. A thousand bills, 6 by 9 inches in size, may be had from the local printer for a price not to exceed S2, and a boy, at SI for the afternoon, will deliver them. This expense should put a handbill into every residence within five blocks of the theater. Such a handbill should contain some special announce- ment as an excuse for its existence; the title and short mention of the nature of some special film to be featured will be sufficient excuse; or a prize voting contest, or special program of specific nature. Noise Wagon. Painted banners are mounted on a wagon — sometimes called a "sandwich wagon" — and driven through the streets, a bell being hung inside which rings continually, or a dnimmer or l)ugler being carried. Its utility is limited. Days when the country people are in town form one excuse for this advertising device. Feature Films. The manager should see the film himself before deciding to feature it. It may be seen at some other theater or at the film exchange; the film exchange will be able to tell the manager where the film is being shown, that he may go there to see it. The 200 MOTION-PICTURE THEATER 37 fact that a specific film is being advertised largely by its manufac- turer is not sufficient basis for a manager to decide to feature it for his patrons, for such advertising may not be justified by the film, or even if so warranted, the film may have real merit and still not be suited to the tastes of the theater as the manager understands them. Having selected a feature film, advertise it only a day ahead, both by theater-front signs and handbills. In addition, a printed program for the next night with the feature film advertised may be handed to patrons leaving the theater on the night before the feature is put on. Be careful that the word "Tomorrow" is promi- nent in the theater-front announcement which is posted a day ahead, or some patron, reading the sign carelessly, may go inside and be disappointed because he did not see the feature film mentioned for the next night. Special F^ograms. An entire program made up of films of some specific nature may be called a special program, and advertised accordingly. "Biograph Night" on which nothing but biograph reels are used, might strike the popular fancy of some neighborhood, while "Travel Night" on which the majority of films are scenic, might "make a hit" with another neighborhood. School Children. A special program of films particularly pleas- ing to children, and to some extent educational or travel, may be given in the afternoon after the close of school, and the result of the experiment noted. Special arrangements with the film exchange will be necessary, and a talk will be needed with the educational or travel films, otherwise they are usually too unfamiliar to the child mind and, therefore, dry and uninteresting. Amateur Night. As a part of one show of the evening, amateurs are invited to entertain the audience, with a time limit of five minutes each; after all have done their acts, each walks upon the stage; each patron in the audience has been requested to decide upon the prize-winning act, and when the selected amateur enters the patrons favoring him applaud. The amateur getting the greatest applause is awarded the advertised prize of the evening. "Amateur Night" is usually made a weekly event in theaters where it is introduced. Contests. This is merely a specialized "amateur night" in which all acts are limited to the same nature, thereby placing the several acts in direct contest with each other. 201 38 THE MOTION PICTURE Double Price. A five-cent theater may run on Saturday night at a ten-cent admission fee. This not only increases the gross receipts for Saturday evening but acts as an advertising feature for the theater. A better show should be given, to justify the double price, in order that the patrons may not think the double price is being charged merely because the manager can get it on Saturday. The program, however, should not require double time, or there will be no gain by the double price. It may be slightly longer in time, and may have advertisable differences in quality if desired. The live manager wnll find some excuse to make a special noise once in a while to get a few new patrons to come to his theater be- cause of the special feature advertised. Renting Films. Subscribe for a magazine devoted to motion- picture interests, and read the advertisements of the film exchanges. Select two or three liberal advertisers near the theater and get their prices. Films contracted for as "not more than thirty days old" will be about the cheapest, quality considered. In the 'city, two reels, daily change, should cost $20 to $25 weekly. This is much better than "one reel ten days and one reel commercial," for "com- mercial" means "junk" to the exchange man If you have film with a timt limit, keep the file of the motion-picture magazine with its list of releases or clip and file the lists of releases and look up every film recei^•ed to make sure that the exchange man is not giving you film older than your contract age. In a small town, the price to be paid for film will be limited by the gross income, and the manager must shop around the film exchanges to get the best he can for his money. Get the benefit of competition among film exchanges by learn- ing what others would charge for the service you are buying, but never change film exchanges without giving your own exchange a chance to meet the other fellow's prices and terms. Song Slides. The slides are rented from the film exchange, although there are some exchanges handhng song slides only. The price is 25 cents to $1 for the set of slides for a week or less, and extra for the sheet music if not returned with the slides. Hiring Employes. In the cities, singer and pianist may be obtained in the neighborhood, by advertising in the daily papers or on the special program handbills. Either one should be em- 202 < ^ « r O S to o < <^ . o> f- ^ W :^ O -3 O ^ 3/ fa t w o w o Pi w a H MOTION-PICTURE THEATER 39 ployed at SI to $1.50 per night. A drummer who is employed else- where during the day should have the same price. Cashier at $4 to $7 weekly is ample in the city. In the small towns, these prices may be cut one-half. The projection operator, with a license and a union in the city, must have $15 for evenings only. In the smaller towns, unless employed for the full day, he may be scheduled for one-half that price; this assumes that he is employed during the day elsewhere. Automatic Music. An automatic piano may be rented or bought — $800 usually will buy one — and the perforated strip music may be obtained from a music exchange or "library" with daily or weekly charge at a price of $1 to $2.50 per month. The automatic piano may furnish the only music for an "all picture" show, or may be used early and late in the evenings to make die pianist's hours shorter and reduce the expense, besides being ready always to furnish music for a full evening when the pianist fails to appear. Vaudeville. The acts must be booked from a dramatic booking agency; no other method is reliable nor satisfactory. A single act by a single actor may be put on at $25 per week and up. Any act will cost $25 per actor, and up from that price. If you are rimning vaudeville, by all means keep posted on what other theaters are doing, and get acquainted with their booking agencies, for com- petition's sake, to see that you are getting the best your money will buy. Splitting the Week. Vaudeville is "weekly change." In the city, where the patronage of a residence district theater is limited to a small area, and in smaller cities, where a large proportion of patrons are likely to visit the theater oftener than one nighf in the week, the plan of "splitting the week" between two theaters is adopted to give each a change of vaudeville in the middle of the week. AMien two theaters are co-operating thus, films as well as vaudeville acts may be "split," particularly if the theaters are in two nearby country towns. Each theater hires a vaudeville act and a few reels of film for the week, and the entire program changes theaters in the middle of the week. Booking agencies will arrange for "spUt weeks" as desired. Keeping Accounts. For theaters whose expenses and incomes run into hundreds of dollars weekly, a full double-entry set of books should be kept. For the smaller theaters, two books will answer 203 40 THE MOTION PICTURE the purpose very well. All theater accounts should be strictly cash. Since the ticket window account is strictly cash, there can be no good business policy in not having the expense account run on the same basis; if the cash from the income account will not pay cash for the expense account, quit the business or think of a good reason why not. For a small theater, a little leather-covered pocket memorandum book may be used to write down all amounts paid out and received, for any purpose whatsoever. ^Memoranda of contracts and agree- ments may be entered in this book. The other book is a book of ruled pages, one for each week of the theater's operation; perhaps a book of fifty-two pages would be a convenient size, covering just a year of operation. The ruling of the pages of this book may be m DAY TITLE -/FimS TITLE e^ SONGS Kzcnns EXPENSES SUN. RENT ELECTRICITY MON. FILM RENT FIANO RENT TUES. SLIDES ADVERTISING WED. EXPRESS SALARY-OPERATOR THUR SINGER FIANST FRl. .. TICKETSaiER ■ " DOOR KEEPER SAT. ■• USHER EXTRAS REMARKS: ADniSSIOM ff£CEJFT5 TOTAL RECEIPTS 0THEF7 RECEIPTS TOTAL EXPENSES TOTAL RECEIPTS NET PROFITS Fig. 9. Blank Form for Weekly Account of a Mot ion- Picture Theater as shown in Fig. 9, or any modification of that form which suits the manager's fancy. A local printer would print a thousand of these on a good quality of letter paper for $4, and he would want about the same money for fifty-two of them, the principal labor being in the preparation of the printing form. By having them printed, the manager may have his own preferred ruling. Books answering the purpose may be bought for a year's business for a dollar or less. Each day the titles of the films may be entered on the page. This is to prevent running the same film twice without a proper inter- 204 MOTION-PICTURE THEATER 41 val between, as might result from an error of the fihn exchange, or from a change in fihn exchanges. The songs are recorded Hke- wise. Fihns and songs which seemed to be "hits" with the audience may be marked with a cross and asked for from the exchange as specials, "repeated by request" for advertising effect. The ticket-window receipts and other receipts should be entered in the pocket memorandum book, and may be noted on the back of the weekly sheet until the end of the week, when the totals may be entered on the face of the weekly sheet, and the net profits for the week may be determined. An extra sheet at the back of the book may have entered upon it in each space the total of the same space on all the weekly sheets. The net profits for the year thus may be shown, as well as a classifica- tion of the expenses for the year. Dull Season. In summer-time in the country, the farmers are too busy to come to town except on Saturday afternoon. In summer- time in the city the people go to the parks or sit on their front porches. "In the good old summer-time," what is the picture-theater manager to do? If he worked hard during the winter, and expects to do the same next winter, it may be to his advantage ultimately to shut up the place for July and August, pay the rent on the vacant house, and take a thorough rest. A little painting and polishing may be done during this interval, and he can open the house with a big whoop and hurrah about September 1. Another method is to make the show straight pictures, and cut the expense sheet to the absolute minimum; perhaps the ticket win- dow will be able to get enough small coin to pay the operating charges. Nothing but a shopper's theater in the shopping center of a large city can run a summer show at winter profits. This excepts the pic- ture show which is a part of a summer amusement park, and also the airdome. They are shows which flourish in the summer-time only. A study of the weekly account sheets as summer approaches will show the dwindling profits. The manager then must decide what his policy for thf^ summer will be. Tickets and Chopper. Tickets will be furnished by the film exchanges, at 15 to 20 cents per thousand, in rolls. They are sold by the cashier, and the proper amount of money which the cashier is 205 42 THE MOTION PICTURE to turn over to the manager may be determined by noting the number of the end ticket of the roll before the show and subtracting it from the end ticket of the roll after the show, multiplying the difference by the price of admission. This number of tickets should be found in the "ticket chopper," or ticket box, and also the numbers of the tickets in the box should correspond, if they were examined. The ticket chopper takes its name from its function. It muti- lates the ticket which is dropped into it in such manner that it may not be used again. Some choppers slit them into ribbons, while others punch holes in them, passing the tickets into one box and the small bits from the holes into another receptacle. In either case, the ticket if reclaimed from the box by fraud would not be suitable for use again. Where a ticket box which does not chop is used, the manager should give his personal attention to destroying the tickets each day, preferably by burning them. Every ticket that is not destroyed by the manager himself means a possible loss of five cents, for it might be used at the door again, even though its destruction is intrusted to another. Change the color every day, having several rolls of different color, and using sometimes one and sometimes another. A ticket of the wrong color dropped into the ticket box will reveal an irregular- ity which may lead to important discoveries in the accounting system. A quiet and accurate "head count" of people entering the theater door on an occasional night, compared with ticket numbers and cashier's receipts, will help to keep this most vital detail of the theater under control. The manager sometimes is confronted with a class of patrons who stay in the theater longer than one show, and, therefore, longer than one admission fee justifies. AMien the house is "holding out" the crowds, each patron of this class reduces the profits of the theater. One method of handling this problem is to take tickets at the door until the first show begins; after that, do not take up the whole ticket, but tear off about one-quarter, permitting the patron to retain the large part of the ticket. This gives each patron entering during the show a torn ticket. Between shows, collect tickets from all in the theater. Those having no torn tickets must have seen the entire performance, and should pay another admission fee or leave the theater. 206 r MOTION-PICTURE THEATER 43 Side Lines for Profit. The patron has a sentiment agaitist any form of advertising in the theater. For the theater in a competitive position, it is a good plan to avoid all semblance of advertising inside the theater — upon the walls or upon the picture screen, either drop curtain or lantern slides. The tone of the theater is improved by leaving the show clean and free from advertising of any kind, par- ticularly if the competing theaters offer objectionable advertising matter. At the same time, the big vaudeville houses of the cities use their advertising drop curtain before the performance and put ad- vertising matter in their street scenes. Also, the legitimate theaters sell candy in the auditorium between the acts and before the per- formance begins. The manager must judge his people on these points and handle his advertising accordingly. Following are a few plans available for increasing the revenue of a theater beyond ticket-window receipts: Mall Posters. This plan is borrowed from the street-car prac- tice of assigning a wall space for advertising matter. The street- car practice is not objectionable, because the space is well chosen and advertising matter is confined strictly to the selected space. As to its application in any specific theater, the sentiment of the patrons must be judged. Many things will pass in a small country town which would not be endured by patrons in a city. Advertising Drop Curtain. The picture screen is an unsightly object in the theater when there is no projected picture upon it. The appearance of the room is improved greatly during the inter- mission by lowering an ornamental drop curtain oyer the picture screen. This drop curtain may contain advertising matter. It should be well put on — at the expense of the advertising client — and a liberal price charged. Advertising Slides. Advertising slides bear advertising matter for the advertising patron, and such slides are thrown upon the screen along with the set of announcement slides with which the program begins, before the motion pictures start. A single advertising slide is hardly objectionable anpvhere, but too many will ruin the show. In connection with advertising slides, insist that the slides be pleasing in appearance and brief in words. Of course the cost of making the slide is paid by the advertiser. Remember that the same people come to your theater every week, and insist upon a 207 44 THE MOTION PICTURE weekly change of the advertising sHde also. The patron who comes the second time comes to see a different show. Not only the adver- tising slides of the paid advertiser must be changed often, but the announcement slides which are in substance advertising slides of the theater itself, must be ehanged. Old slides which have been on the shelf a few weeks may be "run" again as new from time to time, but change the slide program for the same reason that you change the picture program and the song program. Your people want some- thing: new all the time. Don't let any patron get the thought that the manager is asleep or that the theater is not keeping up with every other theater in the land. Program Advertising. This is a practice set by the large theaters. No theater program is complete without advertising matter upon it, and this can be obtained from local merchants at prices which will assist in paying tb.e expense of printing the theater's program, or even yield a profit. In soliciting program advertising, remember that the adver- tisement will increase the size and cost of the program, so that the price must be still greater than the difference in cost which the printer will make. The difference in cost may be learned by getting prices from the printer for the programs with and without advertising. Handbills. The weekly handbill is worth its cost in any city show. The cost may be reduced by carrjdng the advertisement of a local merchant, or two or three in different lines of business, for a ])rice in excess of the added cost of the bills at the printer's. In addition, a proportion of the distributing charge is added to the price for the merchant, always keeping the price to him lower than what it would cost him to print and distribute bills of his own. Candij Kid. The practice of selling candy in theaters before and between acts is well established. Remember in this connection that the patrons come to the theater to beamused. The candy vendor can help much in their entertainment if his "act" is studied. One successfid candy vendor waits only until the old crowd is out and then as soon as the new patrons start in he walks before the picture screen and says something like this: "I know, ladies and gentlemen, that you have come here tonight for a little fun, sport and amuse- ment, and I am going to add to your fun just as much as I possibly 208 MOTION-PICTURE THEATER 45 can; I have tonight a package of candy which I am selling for five cents; as I pass up the aisle please have your change ready." He passes up the aisle with his basket as soon as the aisle is clear, selling candy and making remarks to entertain the crowd: "Don't be afraid to buy it; it's worth the money;" "The young man takes two packages because the young lady knows it's good;" "Every package guaranteed to send you home fat and happy;" "After you eat it, if you don't like it, give it back and I'll refund the nickel;" when the show starts before he has finished his trip, he says, "Keep your eyes on the pictures and hand me your money." ^^our people have come to your theater to be entertained; your candy vendor is making the intermission seem shorter and is positively adding to their entertainment. Avoid the error of giving the candy vendor too much time. An intermission of eleven minutes has been observed and reported, "to allow the candy man to distribute his free samples, make a second tour of the audience to sell his confectionery, then a third tour to sell some songs." Not only will the audience resent the delay to the pictures, but the theater may actually lose money. When the house is running crowded, and patrons are waiting at the door, the number of tickets sold depends upon the speed with which those inside may be shown the entire program, that they may leave and make room for others. A 300-seat house, at 5-cent admission, run- ning a 45-minute program, inider crowded conditions, is making $15 for each program, or about 33 cents per minute while the pictures are on the screen. Assuming that the candy vendor will be able to sell fifty packages of candy at five cents each — a phenomenal sale for so small a house — and at a profit of two cents each to the theater, then for that SI profit on the candy he is entitled to just three minutes' intermission. To extend the intermission one minute is to lose more money at the ticket window than is made at the candy basket. ^Mien the theater manager understands this clearly, he will be in possession of a fundamental principle which applies to all other side lines for profit: Only when the side line does not decrease the ticket window receipts, only when it leaves thtvi unchanged or actually increases them, may it be considered as desirable or profitable. Slot Machines. The lobby, or entrance of the theater in front 209 46 THE MOTION PICTURE of the partition, offers space for a few compact automatic vending machines, if, in the manager's best judgment, such a plan is advisable. If the police regulations of the town will permit, an automatic vend- ing machine may stand on the sidewalk at each side of the theater, just in the foot square of sidewalk space at the end of the theater's side walls. Sheet Music Sales. It is a favor to many patrons to advise them where sheet music of the song may be obtained. An announcement slide, "The song on our program is always for sale at our ticket win- dow," has no objection and does not seem advertising matter because it pertains to the theater. Refreshment Annex. In the airdome, the refreshment business is so much associated with the motion-picture business, and they are so mutually helpful to each other that they usually are nui in con- junction, each to boost the other. In the motion-picture winter theater, the relation cannot be so boldly emphasized or the depart- ure from custom will be noted and adversely commented upon, but a candy store and soda foinitain located near a motion-picture theater will do a larger business than if the theater were not there. 210 i o _ |i H 3 2 « ^^ a, .2 >■ 2:2 « o W ^ O SCENE FROM PHOTOPLAY, "THE LAST APPEAL" Courtesy of Independent Mating Pictures Co., New York I ELECTRICAL PRINCIPLES In the management of a motion-picture machine and theater the operator, even if he be well versed in the practical methods of running circuits for his machine, finds that he needs a knowledge of the elementary principles of electricity and some clear conception of how the electric current behaves in various types of circuits. It must be borne in mind, therefore, that only material deemed perti- nent to the case has been included in this book. Those desiring more information are referred to any standard text. ELECTRICITY IN MOTION— ELECTRICAL CURRENTS Magnetic Effect Due to a Charge in Motion. An electrical charge at rest produces no magnetic effect whatever. This can be proved by bringing a charged body near a compass needle or suspended magnet. It will attract both ends equally well by virtue of the principle of electrostatic induction. If the effect were magnetic, one end should be repelled and the other attracted. Again, if a sheet of zinc, aluminum, or copper is inserted between the deflected needle and the charge, all effect which was produced upon the needle by the charge will be cut off, for the metallic sheet will act as an electric screen. But if such a metal screen is inserted be- tween a compass needle and a magnet, its insertion has no effect at all on the magnetic forces. If, however, a charged Leyden jar is discharged through" a' coil which surrounds an unmagnetizerl Icnitting needle in the manner showai in Fig. 1, the needle will be found, after the discharge, to have become distinctly magnetized. Copyright, 1911, by American School of Correspondence. Fig. 1. Magnetic Effect of Electric Current 213 2 THE MOTION PICTURE This experiment demonstrates the existence of some connection between electricity and magnetism. Just what this connection is, is not yet known with certainty; but it is known that magnetic effects are always observable near the path of a moving electrical charge, while no such effects can ever be observed near a charge at rest. An electrical charge in motion is called an electrical current, and the presence of such current in a conductor is most commonly de- tected by the magnetic effect which it produces. Galvanic Cell. When a Leyden jar is discharged, but a very small quantity of electricity passes through the connecting wires, since the current lasts but a small fraction of a second. If we could keep the current flowing continuously through the wire, we should expect the magnetic effect to be more pronounced. This might be done by discharging Leyden jars in rapiil succession through the wire. In 1786, .however, Galvani, an Italian anatomist at the University of Bologna, accidently discovered that there is a chemical method for producing such a continuous current. His discovery was not understood, however, until Volta, professor of physics at Como, devised an arrangement which is now known sometimes as the voltaic, some- simpic times as the qalvanic cell. Galvanic Cells "^ ....,„ Such a cell consists in its simplest form of a strip of copper and a strip of zinc immersed in dilute sulphuric acid, Fig. 2. If the wires leading from the copper and the zinc are connected for a few seconds to the end of the coil of Fig. 1, when an unmagnetized needle lies within this coil, the needle will be found to be much more stronglv mafjnetized than it was when the Leyden jar was discharged through the coil. Or, if the wire connecting the copper and zinc is simply held above the needle ill the manner shown in Fig. 3, the latter will be found to be strongly deflected. It is evident from these experiments that the wire which connects the terminals of a galvanic cell carries a cur- rent of electricity. Historically, the second of these experiments, performed by the Danish physicist Oersted in 1819, preceded the discovery of the magnetizing effect of currents upon needles. It created a great deal of excitement at the time because it was the first 214 ELECTRICAL PRINCIPLES clew which had been found to a relationship between electricity and magnetism. It might be inferred from the above experiments that the two plates -of a galvanic cell when not connected by a wire carry static Fig. 3. Magnetic Effects of Current positive and negative charges just as do the two coats of a Leyden jar before it is discharged through the wire. This inference can be easily verified with an electroscope. Thus, if a metal plate A, Fig. 4, covered with shellac on its lower side and provided with an insulating handle, is placed upon a similar plate B which is in contact with the knob on an electroscope; and if the copper plate, for example, of a galvanic cell is connected to A and the zinc to B; then, when the connecting wires are removed and the plate A lifted away from B, the leaves of the electroscope will di- verge and when tested will be found to be negatively charged. If the deflection observed in the leaves of the electroscope is too small for the purposes of demonstration, the con- ditions can be bettered by using a battery of from five to ten cells instead of the single cell. If, how- ever, the plates A and B are sufficiently large — say, 3 or 4 inches in diameter — and if their surfaces are very flat, a single cell will be found to be sufficient. If, on the other hand, the copper plate is connected to B and the zinc to A in the above experiment, the elec- Fig. 4. Static Charges on Plates of Galvanic Cell 215 4 THE MOTION PICTURE troscope will be found to be positively charged. This shows clearly that the copper plate possesses a positive electrical charge, while the zinc plate possesses a negative charge, these charges originating in the chemical action within the galvanic cell. In this experiment the two metal plates separated by shellac constitute an electrical condenser which is charged positively on one side and negatively on the other by connecting it with the two plates of the galvanic cell, in precisely the same way in which a Leyden jar is charged by connecting its two coats one to one terminal and the other to the other terminal of a static machine. The poten- tial of the plate B is increased by moving A away from it. This device makes it possible to detect very small potential differences. Comparison of a Galvanic Cell and Static Machine. If one of the terminals of a galvanic cell is touched directly to the knob of the gold-leaf electroscope without the use of the condenser plates A and B of Fig. 4, no divergence of the leaves can be detected; but if one knob of a static machine in operation were so touched, the leaves would be throwTi apart very violently. Since we have seen that the divergence of the leaves is a measure of the potential of the body to which they are connected, we learn from this experiment that the chemical actions going on in a gah anic cell are able to produce between its terminals but very small potential differences in com.- parison with that produced by the static machine between its ter- minals. As a matter of fact, the potential difference between the terminals of the cell is but one volt, while that between the terminals of an electrical machine may be several hundred thousand volts. On the other hand, if the knobs of the static machine are con- nected to the ends of the wire shown in Fig. 3, and the machine operated, the current will not be large enough to produce any ap- preciable effect upon the needle. Since, under these same circum- stances the galvanic cell produced a very large effect upon the needle, we learn that although the cell develops a much smaller p. d. than does the static machine, it nevertheless sends through the wire a very much larger amount of electricity per second. This means merely that the chemical actions which are going on within the cell are able to recharge the plates when they become discharged through the electric wire, far more rapidly than is the static machine able to recharge its terminals after they have once been discharged. 216 ELECTRICAL PRINCIPLES Shape of Magnetic Field about a Current. If we place the wire which connects the plates of a galvanic cell in a vertical position, Fig. 5, and explore with a compass needle the shape of the magnetic field about the current, we find that the mag- netic lines are concentric cir- cles lying in a plane perpen- dicular to the wire and having the wire as their common center. If we reverse the direction of the current, we find that the direction in which the compass needle points reverses also. If the current is very strong, say 40 amperes, this shape of the field can be shown by scattering iron filings on a plate through which the current passes, in the manner shown in Fig. 5. The relation between the direction in which the current flows and the direction in which the positive end of the needle points — this is by definition, the direction of the magnetic field — is given in the following rule: If the right hand grasps the wire as in Fig. G, so that the thumb points in the direction in which the positive electricity is moving, that is, in the direction from the copper toward the zinc, then the magnetic lines encircle the wire in the same direction as do Fig. 5. Magnetic Field Around a Conductor Fig. 6. Right-Hand Screw Rule for Direction of Magnetic Field the fingers of the hand. Another way of stating this rule is as follows: The relation between the direction of the current in a wire and the di- rection of the magnetic lines aboid it, is the same as the relation be- tween the direction of the forivard motion of a right-handed screw and the direction of rotation when it is being driven in. In this form the rule is known as the right-hand screw rule. 217 6 THE MOTION PICTURE Measurement of Electrical Currents. Electrical currents are, in general, measured by the strength of the magnetic effect which they are able to produce under specific conditions. Thus, if the wire carrying a current is wound into circular form as in Fig. 7, the right-hand screw rule shows us that the shape of the magnetic field at the center of the coil is similar to that shown in the figure. If, then, the coil is placed in a north-and-south plane and a compass needle is placed at the center, the passage of the current through the coil tends to deflect the needle so as to make it point east and west. The amount of deflection under these conditions is taken as the measure of current strength. The unit of current is called the ampere and is, in fact, approximately the same as the current which, flowing through a circular coil of three turns and 10 centimeters radius, set in a north-and-south plane, will produce at Washington Fig. 7. Plotting Field About Circular Conductor a deflection of 45 degrees in a small compass needle placed in its cen- ter, as in Fig. 7. Nearly all current-measuring instruments, com- monly called ammeters, consist essentially either of a small magnet suspended at the center of a fixed coil as in Fig. 7, or of a movable coil suspended between the poles of a fixed magnet. The passage of the current through the coil produces a deflection, in the first case, of the magnetic needle with reference to the fixed coil, and in the second case, of the coil with reference to the fixed magnet. If the instrument has been suitably calibrated, the amount of the deflection gives at once the strength of the current in amperes. Electromotive Force and Its Measurements. The potential difference which a galvanic cell or other generator of electricity is able to maintain between its terminals when these terminals are not connected by a wire, i. e., the total electrical pressure which the 218 ELECTRICAL PRINCIPLES 7 generator is capable of exerting, is commonly called its electromotive force, or e. m. f. The e. m. f of an electrical generator may then be defined as its capacity for producing electrical pressure, or p.d. This p. d. might be measured by the deflection produced in an electroscope, or other similar instrument, when one terminal was connected to the case of the electroscope and the other terminal to the knob. Potential differences are in fact measured in this way in all so-called electrostatic voltmeters, which are now coming more and more into use. The more common type of potential difference measurers, so- called voltmeters, consists, however, of an instrument made like an ammeter, save that the coil of wire is made of an enormous number of turns of extremely fine wire, so that it carries at very small current. The amount of current which it does carry, however, and therefore the amount of deflection of its needle, is taken as proportional to the difference in electrical pres- sure existing between its ends when these are touched to the two points whose p. d. is sought. The prin- ciple underlying this type of voltmeter will be better understocxJ from a consideration of the following water analogy. If the stop- cock K Fig. 8, in the pipe connecting the water tanks C and D is closed, and if the water wheel A is set in motion by applying a weight W , the wheel will turn until it creates such a difference in the water levels between C and D that the back pressure against the left face of the wheel stops it and brings the weight W to rest. In precisely the same way, the chemical action within the galvanic cell whose terminals are not joined, Fig. 9, develops positive and negative charges upon these terminals, that is, creates a p. d. between them, until the back electrical pressure through the cell due to this p. d. is sufficient to put a stop to further chemical action. Fig. 8. Hydrostatic Analogy of Potential Difference 219 8 THE MOTION PICTURE Now, if the water resen-oirs, Fig. S, are put in communication by opening the stop-cock K, the difference in level between C and D will begin to fall, and the wheel will begin to build at up again. But if the carrying capacity of the pipe a b is small in comparison with the capacity of the wheel to remove water from D and to supply it to C, then the difference of level which permanendy exists between C and D when K is open will not be appreciably smaller than when it is closed. In this case the current which flows through AB may obviously be taken as a measure of the difference in pressure which the pump is able to maintain between C and D when K is closed. In precisely the same way, if the terminal C and D of the cell. Fig. 9, are connected by attaching to them the terminals a and b of any conductor, they at once begin to discharge through this conductor, and their p. d., there- fore, begins to fall. But if the chemical action in the cell is able to recharge C and D very rapidly in comparison with the ability of the wire to discharge them, then the p. d. between C and D will not be appreciably lowered by the presence of the connecting conductor. In this case the current which flows through the conducting coil, and, there- fore, the deflection of the needle at its center, may be taken as a mejisure of the electrical pressure developed by the cell, that is, of the p. d. between its unconnected terminals. The common voltmeter is, then, exactly like an ammeter, save that its coil offers so high a resistance to the passage of electricity through it that it does not assist appreciably in discharg- ing, that is, in reducing the p. d. between the points to which it is connected. The unit of p. d. may be taken for practical purposes as the electrical pressure produced by a simple galvanic cell consisting of zinc and copper immersed in dilute sidphuric acid. It is named a volt in honor of Volta. Electromotive Forces of Galvanic Cells. ^Mien a voltmeter of any sort is connected to the terminals of a galvanic cell, it is found that the deflection produced is alt(jgether independent of the shape Fig. 9. Principle of Com- mon Voltmeter 220 ELECTRICAL PRINCIPLES 9 or size of the plates or their distance apart. But if the nature of the plates is changed, the deflection changes. Thus, while copper and zinc in dilute sulphuric acid have an e. m. f. of one volt, carbon and zinc show an e. m. f. of at least L5 volts, while carbon and copper will show an e. m. f. of very much less than a volt. Similarly, by changing the nature of the hquid in which the plates are immersed, we can produce changes in the deflection of the voltmeter. We learn, therefore, that the e. m. f. of a galvanic cell depends simply up- on the materials of which the cell is composed and not at all upon the shape, size, or distance apart of the plates. Electrical Resistance. If the terminals of a galvanic cell are connected first to, say, 10 feet of No. 30 copper wire, and then to 10 feet of No. 30 German-silver wire, it is found that a compass needle placed at a given distance from the copper wire will show a much larger deflection than when placed the same distance from the German-silver wire. A cell therefore, which is capable of develop- ing a certain fixed electrical pressure is able to force very much more current through a given wire of copper than through an exactly similar wire of German-silver. We say, therefore, that German-silver offers a higher resistance to the passage of electricity than does copper. Similarly, every particular substance has its own characteristic power of transmitting electrical currents. Silver being the best con- ductor of any known substances, the resistances of different sub- stances are commonly referred to silver as a standard, and the ratio between the resistance of a given wire of any substance and the resistance of an exactly similar silver wire is called the specific re- sistance of that substance. The specific resistance of some of the commoner metals are as follows: Silver 1.00 Soft iron 7.40 German silver 20.4 Copper 1.13 Nickel 7.87 Hard steel 21.0 Aluminum 2.00 Platinum 9.00 Mercury 62.7 The unit of resistance is the resistance of 0° of a column of mer- cury 10G.3 centimeters long and 1 square millimeter in cross-section. It is called an ohm, in honor of the great German physicist, Georg Ohm (1789-1854). A length of 9.35 feet of No. 30 copper wire, or 6.2 inches of No. 30 German-silver wire, has a resistance of about one ohm. Copper wire of the size shown in Fig. 10 has a resistance of about 2.62 ohms per mile. 221 10 THE MOTION PICTURE The resistances of all metals increase with rise in temperature. The resistances of liquid conductors, on the other hand, usually decrease with rise in temperature. Carbon and a few other solids show a similar be- ^'^ ^"c^ppTr^wfre"^ '^°' havior: the filament in an incandescent lamp has only about half the resistance when hot that it has when cold. The resistances of wires of the same material are found to be directly proportional to their lengths, and inversely proportional to their cross-sections. Ohm's Law. In 1827, Ohm announced the disco\cry that the currents furnished by different galvanic cells, or combinations of cells, are always directly proportional to the e. m. f.'s existing in the circuits in which the currents flow, and inversely proportional to the total resistances of these circuits; that is, if C represents the current in amperes, E the e. m. f. in volts, and R the resistance of the circuit in ohms, then Ohm's law as applied to the complete circuit is E electromotive force C = — ; i. e., current = ; R resistance As applied to any portion of an electrical circuit, Ohm's law is pd . potential differeJice C= — ; /. parts of conimerfial suli)luiric acid. 226 ELECTRICAL PRINCIPLES 15 chromate attacks the zinc even when the circuit is open, it is neces- sary to lift the zinc from the hcjiiid by the rod A, when the cell is not in use. Such cells are useful where large currents are needed for a short time. The great disadvantages are that the fluid deteriorates rapidly, and that the zinc cannot be left in the liquid. Danicll Cell. The Daniell cell consists of a zinc plate immersed in zinc sulphate, and a copper plate immersed in copper sulphate, the two liquids being kept apart either by means of a porous earthen cup, as in the types shown in Fig. 14, or else by gravity, as in the type shown in Fig. 15. This last type, commonly called the gravity, or % O o o9 ziOCfG Fig. 14. Section of Daniell Cell Danio'l Cell (Commercial Type) croicfoot type, is used almost exclusively on telegraph lines. The copper sulphate, being the heavier of the two liquids, remains at the bottom about the cop])er plate, while the zinc sulphate remains at the top about the zinc plate. In this cell polarization is almost entirely avoided, for the reason that no opportunity is given for the formation of hydrogen bubbles. For, just as the hydrochloric acid solution consists of positive hydro- gen ions and negative chloride ions in water, so the zinc sulphate (ZnSO^) solution consists of positive zinc ions and negative SO^ ions. Now the zinc of the zinc plate goes into solution in the zinc sulphate in precisely the same way that it goes into solution in the 227 16 THE MOTION PICTURE hydrochloric acid of the simple cell. This gives a positive charge to the solution about the zinc plate, and causes a movement of the positive ions between the two plates from the zinc toward the copper, and of negative ions in the opposite direction, both the Zn and the SO^ ions being able to pass through the porous cup. Since the posi- tive ions about the copper plate consist of atoms of copper, it will be seen that the material which is driven out of solution at the copper plate, instead of being hydrogen, as in the simple cell, is metallic copper. Since, then, the element which is deposited on the copper plate is of the same molecvilar structure as that of which it already consists, it is clear that neither the electromotive force nor the resistance of the cell can be changed by the presence of this deposit, i. e., the cause of the polarization of the simple cell has been removed. The great advantage of the Daniell cell lies in the relatively high degree of constancy in its e. m. f. (1.08 volts). It has a com- paratively high internal resistance — one to six ohms — =and is, therefore, incapable of produc- ing very large currents, about one ampere at most. It will furnish a very constant cur- rent, however, for a great length of time; in fact until all of the copper is driven out of the copper sulphate solution. In order to keep a constant supply of the copper ions in the solution, copper sulphate crystals are kept in the compartment »S of the cell of Fig. 14, or in the bottom of the gravity cell. These dissolve as fast as the solution loses its strength through the deposition of copper on the copper plate. The Daniell is a so-called closed-circuit cell, i. c, its circuit should be left closed — through a resistance of thirty or forty ohms — whenever the cell is not in use. If it is left on open circuit, the copper sulphate diffuses through the porous cup, and a brownish muddy deposit of copper or copper oxide is formed upon the zinc. Pure copper is also deposited in the pores of the porous cu|). Both of these actions damage the cell. \Mien the circuit is cl.)sed, however, since the electrical forces always keep the copper Fig. 15. Gravity Cell 228 ELECTRICAL PRINCIPLES 17 Leclanche Cell ions moving toward the copper plate, these damaging effects are to a large extent avoided Leclanche Cell, The Leclanche cell, Fig. 16, consists of a zinc rod in a solution of ammonium chloride — 150 g. to a liter of water — and a carbon plate placed inside of a porous cup which is packed full of manganese dioxide and powdered graphite or carbon. As in the simple cell, the zinc dissolves in the liquid, and hydrogen is liberated at the carbon, or positive, plate. Here it is slowly attacked by the manganese dioxide. This chemical action is, however, not quick enough to prevent rapid polarization when large currents are taken from the cell. The cell slowly recovers when allowed to stand for a while on open circuit. The e. m. f. of a Leclanche cell is about 1.5 volts, and its initial internal resistance is somewhat less than an ohm; It, therefore, furnishes a momentary current of from one to three amperes. The immense advantage of this type of cell lies in the fact that the zinc is not at all eaten by the ammonium chloride when the circuit is open, and that, therefore, unlike the Daniell or bichromate cells, it can be left for an indefinite time on open circuit without deterioration. Leclanche cells are used almost exclusively where momentary currents only are needed, as, for example, on door-bell circuits. The cell requires no attention for years at a time, other than the occasional addition of water to replace loss by evaporation, and the occasional addition of ammo- nium chloride (NH^Cl) to keep positive NH^ and negative CI ions in the solution. Dry Cell. The dry cell is only a modified form of the liCclanche cell. It is not really dry, since the zinc and carbon plates are im- bedded in moist paste which consists usually of one part of crystals of ammonium chloride, three parts of plaster of Paris, one part of zinc oxide, one part of zinc chloride, and two parts of water. The plaster of Paris is necessary in order to give the paste the re- quired rigidity. As in the Leclanche cell, the current is produced by the chemical action of the ammonium chloride upon the zinc plate which forms the outside wall of the cell. 229 18 THE MOTION PICTURE Combinations of Cells. There are two ways in which cells may be combined: First, in series; and second, in parallel. When they are connected in series the zinc of one cell is joined to the copper of the second, the zinc of the second to the copper of the third, etc., the copper of the first and the zinc of the last being joined to the ends of the external resistance, Fig. 17. The e. m. f. of such a combina- tion is the sum of the e. m. f.'s of the single cells. The internal re- sistance of the combination is also the sum of the internal resistances of the single cells. Hence, if the external resistances are very small, the current furnished by the combination will not be larger than that furnished by a single cell, since the total resistance of the circuit has been increased in the same ratio as the total e. m. f. But if the ex- /Tnr2Rr\ /iymr\ TC^^Z^- lcj----: "ci^^^ Fig. 17. Cells Connected ki Series ternal resistance is large, the current produced by the combination will be very much greater than that pn^duced by a single cell. Just how much greater can always be determined by applying Ohm's law, for if there are n cells in series, and E is the e. m. f. of each cell, the total e. ra. f. of the circuit is n E. Hence if Re is the external resist- ance and Ri the internal resistance of a single cell, then Ohm's law gives nE ' C = Re + tfRi If the ?/ cells are connected in parallel, that is, if all the coppers are connected together ant! all the zincs, as in Fig. 18, the e. m. f. of the combination is only the e. m. f. of a single cell, while the internal .1 resistance is — of that of a single cell, since connecting the cells in 230 ELECTRICAL PRINCIPLES 19 this way is simply equivalent to multiplying the area of the plates n times. The current furnished by such a combination will be given by the formula E C = - /?. + R^ If, therefore, Rg is negligibly small, as in the case of a heavy copper wire, the current flowing through it will be n times as great as that which couid be made to flow through it by a single cell. These considerations show that the niles which should govern the combination of cells are as follows: When the external resistance is large in com- pnrison with the internal resistance of a single cell, the cells should be connected in series. When the external resistance is small in com- parison with the internal resistance of a single cell, the cells should he connected in parallel. Storage Battery. If two lead plates are immersed in sulphuric acid and the current sent through the cell, the anode or plate at which the current enters the solution will be foinid in the course of a few minutes to turn dark brown. This brown coat is a compound of lead with the oxygen which, in the case of the platinum electrodes, was evolved as a gas. The other lead plate is not affected by the hydrogen, which is, in this case, as in that of the platinum, evolved as a gas. Since the passage of the current through this cell has left one plate unchanged, while it has changed the surface of the other plate to a new substance, namely, lead peroxide, PbO,, it might be expected that if the charging battery were removed, and these two dissimilar plates connected with a wire, a current will flow through the wire, for the arrangement is now essentially a simple galvanic cell, which in its essentials consists simply of two dissimilar plates immersed in an electrolyte^a conducting liquid other than a molten metal. In this case the plate ha\nng the lead peroxide upon it cor- responds to the copper of an ordinary cell, and the unchanged lead Fig. IS. Cells Con- nected in Parallel 231 20 THE MOTION PICTURE plate to the zinc. The arrangement will furnish a current until the lead peroxide is all used up. The only important difference between a commercial storage cell and the two lead plates just considered, is that the former is provided in the process of manufacture with a very much thicker coat of the active material — lead peroxide on the posi- tive plate, and a porous, spongy lead on the negative — than can be formed by a single charging such as we considered. In one tyY>e of storage cell this active material is actually formed by the repeated charging and discharg- ing of plates which are originally ordinary sheets of lead. With each new charging a slightly thicker layer of the lead peroxide is formed. In the more common type of commer- cial cell the active material is pressed into interstices of the plate in the form of a paste. It will be seen from this discussion that a storage battery is not, properly speaking, a device for storing electricity. It is rather a device in which the electrical cur- rent produces chemical changes, and these new chemicals, so long as they last, are capable of generating a new electrical current. 19. Magnetic Prop- erties of a Loop ELECTROMAGNETISAl Magnetic Properties of a Loop. We have seen that an elec- trical current is surrounded by a magnetic field the direction of which is given by the right-hand rule. We have seen also that a loop or coil of wire through which a current flows produces a magnetic field of the shape shown in Fig. 7. Now, if such a loop is suspended in the manner shown in Fig. 19 while a current is passed through it, it is found to slowly set itself in an east-and-west plane, and so that the face of the loop from which the magnetic lines emerge, Fig. 20, is toward the north. In other words, the loop will be found to behave with respect Fig 20. Macnptic Properties of a Loop 232 ELECTRICAL PRINCIPLES 21 to the earth or to any other magnet precisely as though it were a flat magnetic disk whose boundary is the wire, the face which turns toward the north, that is, that from which the magnetic hues emerge, being an N pole and the other an S pole. Magnetic Properties of a Helix. If a wire carrying a current be wound in the form of a helix and held near a suspended magnet Fig. 21. Magnetic Properties of a Helix as in Fig. 21, the coil will be found to act in every respect like a mag- net, with an N pole at one end and an S pole at the other. This result might have been predicted from the fact that a single loop is equivalent to a flat-disk magnet. For when a series of such disks is placed side by side, as in the helix, the result must be the z'''' r~~--. Direction Fig. 22. Magnetic Field Fig. 23. Right-Hand Rule for a Helix About a Helix same as placing a series of disk magnets in a row, the N pole of one being directly in contact with the S pole of the next, etc. These poles would, therefore, all neutralize each other except at the two ends. We, therefore, get a magnetic field of the shape shown in Fig. 22, the direction of the arrows representing as usual the direction in which an N pole tends to move. Rules for North and South Poles of a Helix. The right-hand 233 22 THE MOTION PICTURE Fig. 24. A Simple Electro- magnet and Its Field nile as already given is sufficient in every case to determine which is the N and which the S pole of a helix, i. e., from which end the lines of magnetic force emerge from the helix and at w^hich end they enter it. But it is found convenient, in the consideration of coils, to restate the right-hand rule in a slightly different way, Fig. 23, thus: If the coil is grasped in the right hand in such a umy that the fingers point in the direction in which the current is flowing in the wires, the thumh will point in the direction of the north pole of the helix. Similarly, if the sign of the poles is kno\\Ti, but the direction of the current unknown, the latter may be determined as follows: If the right hand is placed against the coil ivith the thumb pointing in the direction of the lines of force, i. e., toward the north pole of the helix, the fingers will pass around the coil in the direction in which the current is flowing. Electromagnet. If a core of soft iron be inserted in the helix, Fig. 24, the poles will be found to be enormously stronger than before. This is because the core is magnet- ized by induction from the field of ■ — "^^^ "^^^^^ 'Mill y 111 ii 111 ii III II In Mill ll I lll 111''!' i' I" 111!'" v^ 111 II III II "'1' Hill till 1 1111 1 HM l| h I II h I 'i II II I Fig. 25. Horseshoe Electromagnet with Armature Fig. 26. Field of Horseshoe Electromagnet the helix in precisely the same way in which it would be magnetized by induction if placed in the field of a permanent magnet. The new field strength about the coil is now the sum of the fields due to the core and that due to the coil. If the current is broken, the core will at once lose the greater part of its magnetism. If the current is re- 234 SCENE FROM "POEMS IN PICTURES," BY GAUMONT ^ ^ ^ ^ A Series of Imaginative Conceptions Which Deeply Impressed ^he^^^^^^^ Element of the Country Courtesy of the Kleine Optical Co., Ltiicago ELECTRICAL PRINCIPLES 23 versed, the polarity of the core will be reversed. Such a coil with a soft-iron core is called an electromagnet. The strength of an electromagnet can be very greatly increased by giving it such form that the magnetic lines can remain in iron throughout their entire length instead of emerging into air, as they do in Fig. 24. For this reason electromagnets are usually built in the horseshoe form and provided with an armature A, Fig. 25, through which a complete iron path for the lines of force is estab- lished as shown in Fig. 2G. The strength of such a magnet depends Fig. 27. Simple Electric Bell and Connections chiefly upon the number of ampere-turns which encircle it, the ex- pression ampere-turns denoting the product of the number of turns of wire about the magnet by the number of amperes flowing in each turn. Thus a current of y^ ampere flowing 1,000 times around a core will make an electromagnet of precisely the same strength as a current of 1 ampere flowing 10 times about the core. Electric Bell. The electric bell, Fig. 27, is one of the simplest applications of the electromagnet. Wlien the button P is pressed, the electric circuit of the battery is closed and a current flows in at A, through the magnet, over the closed contact C, and out again at B. Rut no sooner is this current established than the electromagnet E pulls over the armature a, and in so doing breaks the contact at C. k 235 24 THE MOTION PICTURE This stops the current and demagnetizes the magnet E. The arm- ature is then thrown back against C by the elasticity of the spring s which supports it. No sooner is the contact made at C than the current again begins to flow and the former operation is repeated. Thus the circuit is automatically made and broken at C and the hammer H is, in consequence, set into rapid vibration against the rim of the bell. LAWS OF CURRENT FLOW RESISTANCE All substances resist the passage of electricity, but the resist- ance offered by some is very much greater than that offered by others. Metals have by far the least resistance and, of these, silver possesses the least of any. In other words, silver is the best conduc- tor. If the temperature remains the same, the resistance of a conduc- tor is not affected by the current passing through it. A current of ten, twenty, or any number of amperes may pass through a circuit, but its resistance will l)e unchanged with constant temperature. Re- sistance is affected by the temperature and also by the degree of hardness. Annealing decreases the resistance of a metal. Conductance. Conductance is the inverse of resistance, that is, if a conductor has a resistance of R ohms, its conductance is equal to A. R Resistance Proportional to Length. The resistance of a con- ductor is directly proportional to its length. Hence, if the length of a conductor is douliled, the resistance is doubled, or if the length is divided, say into three equal parts, then the resistance of each part is one-thin! the total resistance. Example. The resistance of 1,28.3 feet of a certain wire is 6.9 ohms. What is the resistance of 1 42 feet of the same wire? Soliitinn. As the resistance is directly proportional to the length we have the proportion required reaifttnnce : 6.9 : : 112 : 1283 required resistance 142 or, = 6.9 1283 142 Hence, required resistance = 6.9 X 1283 = .76 ohm (approx.) Ans. .76 ohm. 236 ELECTRICAL PRINCIPLES 25 Example. The resistance of a wire having a length of 521 feet is .11 ohm. What length of the same wire will have a resistance of .18 ohm? Solution. As the resistance is proportional to length, we have the pro- portion required length : 521::. 18:. 11 required length .18 or, = 521 .11 . , , , -18 Hence, required length = 521 X — = 852 feet (approx.) Ans. 852 feet. Resistance Inversely Proportional to Cross=Section. The re- sistance of a conductor is inversely proportional to its cross-sec- tional area. Hence the greater the cross-section of a wire the less is its resistance. Therefore, if two wires have the same length, but one has a cross-section three times that of the other, the resist- ance of the former is one-third that of the latter. Example. The ratio of the cross-sectional area of one wire to that of 257 another of the same length and material is — • The resistance of the former 101 is 16.3 ohms. What is the resistance of the latter? Solution. As the resistances are inversely proportional to the cross- sections, the smaller wire has the greater resistance, and we have the proportion required resistance : 10. 3 : : 257 : 101 required resistance 257 or, '■ = — 16.3 101 257 Hence, required resistance = 10.3 X — ^ 101 = 41.5 ohms (approx.) Ans. 41.5 ohms Example. If the resistance of a wire of a certain length and having a cross-sectional area of .0083 square inch is 1.7 ohms, what would be its resist- ance if the area of its cross-section were .092 square inch? Solution. Since increasing the cross-sectional area of a wire decreases its resistance, we have the proportion required resistance : 1.7 : : .0083 : .092 required resistance .0083 or, 1.7 .092 .0083 Hence, required resistance = 1.7 X .092 = .15 ohm (approx.) Ans. .15 ohm. 237 26 THE MOTION PICTURE As the area of a circle is proportional to the square of its diam- eter, it follows that the resistance of round conductors are inversely proportional to the squares of their diameters. Example. The resistance of a certain wire having a diameter of .1 inch is 12.6 ohms. What would be its resistance if the diameter were increased to .32 inch? Solution. The resistances being inverselj' proportional to the squares of the diameters, we have required resistance : 12. G : : .1^ : .32^ required resistance .1^ or, = — k 12.6 .32^ .1^ Hence, required resistance = 12.6 X — -„ .32^ 12.6 X .01 .1024 = 1.23 ohms (approx.) Ans. 1.23 ohms. Specific Resistance. The specific resistance of a substance is the resistance of a portion of that substance of unit length and unit cross-section at a standard temperature. The units commonly used are the centimeter of the inch, and the temperature that of melting ice. The specific resistance may therefore be said to be the resistance (usually stated in microhms) of a centimeter cube or of an inch cube at the temperature of melting ice. If the specific resistances of two substances are known, then their relative resistance is given by the ratio of the specific resistances. Conductivity. Conductivity is the reciprocal of specific resist- ance. Example. A certain copper wire at the temperature of melting ice has a resistance of 29.7 ohms. Its specific resistance — resistance of 1 centi- meter cube in microhms — is 1.594, and that of platinum is 9.032. What would be the resistance of a platinum wire of the same size and length of the copper wire, and at the same temperature? Solution. The resistance would be in direct ratio of the specific resist- ances, and we have the projiortion required resistance : 29.7 : : 9.032 : 1.594 IT • , • „ - 9032 Hence, required resistance = 29.7 X 1.594 = 168 ohms (approx.) Ans. 168 ohms. 238 ELECTRICAL PRINCIPLES 27 Calculation of Resistance. From the preceding pages it is evident that resistance varies directly as the length, inversely as the cross-sectional area, and depends upon the specific resistance of the material. This may be expressed conveniently by the for- mula L A in which R is the resistance, L the length of the conductor, A the area of its cross-section, and s the specific resistance of the ma- terial. Example. A telegraph relay is wound with 1,800 feet of wire .010 inch in diameter, and has a resistance of 150 ohms. What will be its resist- ance if wound with 40 feet of wire .022 inch in diameter? Solution. If the wires were of equal length, we should have the pro- portion required resistance: 150 : : (.010)^ : (.022)^ (.010)^ or, required resistance = 150 X = 30.99 + ohms (.022)2 For a wire 400 feet long, we have, therefore, by direct proportion, 400 required resistance = X 30.99 = 6.88 + ^ 1,800 Ans. 0.88 + ohms. If a circuit is made up of several dilTerent materials joined in series with each other, the resistance of the circuit is equal to the sum of the resistances of its several parts. In calculating the re- sistance of such a circuit, the resistance of each part should first be calculated, and the sum of these resistances will be the total re- sistance of the circuit. In Table I is given the resistance of chemically pure substances at 0° centigrade or 32° Fahrenheit in International ohms. The first column of numbers gives the relative resistances when that of an- nealed silver is taken as unity. For example, mercury has 62.73 times the resistance of annealed silver. The second and third col- umns give the resistances of a foot of wire .001 inch in diameter, and of a meter of wire 1 millimeter in diameter, respectively. The fourth and fifth columns give respectively the resistance in mi- crohms of a cubic inch and cubic centimeter, that is, the specific re- sistances. 239 28 THE MOTION PICTURE TABLE I Relative Resistance of Chemically Pure Substances at 32° F. Inter= national Olims Metals Relative Resist- ance Resistance of a wire 1 foot long .001 in. in diameter Resistance of a wire 1 m. long 1 mm. in diameter Resistance in Micro Imis Cubic Inch Cubic Cen- timeter Silver, annealed 1.000 9.023 .01911 .5904 1.500 Copper, annealed 1.063 9.585 .02028 .6274 1.594 Silver, hard drawn 1.086 9.802 .02074 .6415 1.629 Copper, hard drawn 1.086 9.803 .02075 .6415 1.629 Gold, annealed 1.369 12.35 .02613 .8079 2.052 Gold, hard drawn 1.393 12.56 .02661 .8224 2.088 Aluminum, annealed 1.935 17.48 .03700 1.144 2.904 Zinc, pressed 3.741 33.76 .07143 2.209 5.610 Platinum, annealed 6.022 54.34 .1150 3.555 9.032 Iron, annealed 6.460 58.29 .1234 3.814 9.689 Lead, pressed 13.05 117.7 .2491 7.706 19.58 German silver 13.92 125.5 .2659 8.217 20.87 Platinum-silver alloy (^ platinum, § silver) 16.21 146.3 .3097 9.576 24.32 Mercury 62.73 570.7 1.208 37.05 94.06 A very small portion of foreign matter mixed with a metal greatly increases its resistance. An alloy of two or more metals always has a higher specific resistance than that of any of its con.stituents. For example, the conductivity of silver mixed with 1.2 per cent in volume of gold, will be 59 when that of pure silver is taken as 100. Annealing reduces the resistance of metals. The following examples are given to illustrate the use of Table I in connection with the formula R = s -^ and to show the ap])li- cation of preceding laws. ExAMFLR. From the .specific resistance of annealed aluminum as given in the next to the last column of the tahlc, calculate the resistance given in the second column of figures for that substance. Solution. The resistance in microhms of a culiic inch of annealed alumi- num at 32° F. is 1.144, which is equal to .000001144 ohms. The resistance of a wire 1 foot long and .001 inch in diameter is recjuired. According to the formula s = .000001144, L = 1 foot = 12 inches and 4 3.1416 X .001^ = .0000007854 sq. in. 240 ELECTRICAL PRINCIPLES 29 Substituting these values in the formula L we have R = s ^ A 12 R = .000001144 X .0000007854 = 17.48 ohms Ans. 17.48 ohms. Example. The resistance in microhms of a cubic centimeter of annealed platinum at 32° F. is 9.032. What is the resistance of a wire of the same substance one meter long and one millimeter in diameter at the same temper- ature? Solution. In the formula for resistance we have the quantities s = 9.032 microhms = .000009032 ohms; L = 1 meter = 100 centimeters; and Tzd^ 3.1410 X .1^ A = — = = .007854 sq. cm. 4 4 * the diameter being equal to 1 millimeter = .1 cm. Substituting these values we have 100 R = .000009032 X .007854 = .115 ohm Ans. .115 ohm. Example. From Table I the resistance of 1 foot of pure annealed silver wire .001 inch in diameter at 32° F. is 9.023 ohms. What is the resistance of a mile of wire of the same substance .1 inch in diameter at that temperature? Solution. As the resistance of wires is directly proportional to their length and inversely proportional to the squares of their diameters, the re- quired resistance is found by multiplying the resistance per foot by 5,280 and the product by the inverse squares of the diameters. j .001 ) 2 Therefore, R = 9.023 X 5280 X j j" = 4. 70 ohms (approx.) Ans. 4.76 ohms. Example. A mile and one-half of an annealed wire of pure iron has a resistance of 46.1 ohms. What would lie the resistance of hard-drawn wire of pure copper of the same length and diameter, assuming each to be at the temperature of melting ice? Solution. The only factor involved by this example is the relative resist- ance of the two metals. From Table I, annealed iron has 6.460 and hard- drawn copper 1.086 times the resistance of annealed silver. Hence, the resist- ance of the copper is to that of the iron as 1.080 is to 6.460, and the required resistance is 1 .080 R = 46.1 X = 7.75 ohms (approx.) 6.460 Ans. 7.75 ohms. 241 30 'THE MOTION PICTURE Example. If the resistance of a wire 7,423 feet long is 18.7 ohms, what would be its resistance if its length were reduced to 6,253 feet and its cross- section made one half again as large? Solution. As resistance is directly proportional to the length, and in- versely proportional to the area of the cross-section, the required resistance is 02 53 2 R = 18.7 X X — =10.5 ohms (approx.) 7423 3 Ans. 10.5 ohms. Resistance Affected by Heating. The resistance of metals depends upon the temperature, and the resistance is increased by heating. The heating of some substances, among which is carbon, causes a decrease in their resistance. The resistance of the fila- ment of an incandescent lamp when lighted is only about half as great as when cold. All metals, however, have their resistance in- creased by a rise in temperature. The percentage increase in resist- ance with rise of temperature varies with the different metals, and varies slightly for the same metal at different temperatures. The increase is practically uniform for most metals throughout a con- siderable range of temperature. The resistance of copper increases about .4 per cent per degree centigrade, or about .22 per cent degree Fahrenheit. The percentage increase in resistance for alloys is much less than for the simple metals. Standard resistance coils are, there- fore, made of alloys, as it is desirable thnt their resistance should be as nearly constant as possible. The change in resistance of one ohm per degree rise in tem- perature for a substance is called the temperature coefficient for that su Instance. Table II gives the temperature coefficients for a few substances. If the resistance of a conductor at a certain temperature is known, the resistance the conductor will have at a higher temperature may be found by multiplying the temperature coefficient for the sub- stance, l)y the number of degrees increase and Ijy the resistance at the lower temperature, and adding to this result the resistance at the lower temperature. The product of the temperature coefficient by the number of degrees increase gives the increase in resistance of one ohm through that number of degrees, and multiplying this by the number of ohms gives the increase in resistance for the conduc- tor. The result obtained is practically correct for moderate ranges of temperature. 242 ELECTRICAL PRINCIPLES 31 TABLE II Temperature Coefficients Mateiiial Rise in R. of 1 Ohm When Heated 1 1' F. i^C. Platinoid Platinum-silver German silver Platinum Silver Copper, aluminum Iron .00012 .00014 .00022 .0019 .0021 .0022 .0026 .00022 .00025 .00040 .0035 .0038 .0040 .0046 The above method of calculating the resistance of conductors at increased temperature is conveniently expressed by the follow- ing formula where R^ is the resistance at the higher temperature, R^ that at the lower temperature, a the temperature coefficient for the sub- stance, anfl / the number of degrees change. From the preceding formula it follows that if the resistance at the higher temperature is known, that at the lower temperature will be given by the formula R R. ' 1 + at In calculating resistances at different temperatures, the tem- perature coefficient based on the Fahrenheit scale should be used if the number of degrees change is given in degrees Fahrenheit, and that based on the centigrade scale if given in degrees centi- grade. Example. The resistance of a coil of German silver wire at 12° C. is 1 ,304 ohms. What would l)e its resistance at a temperature of 60° C? Solidio7i. From the statement of the example R^ = 1,304, / = 60 — 12 48, and from Table II, a = .0004. Substituting these values in the formula /? 2 = Rj^ {l+at), we have R^ = 1304 (1 -;- .0004 X 48) = 1304 X 1.0192 = 1329 ohms (approx.) Ans. 1329 ohms. 243 32 THE MOTION PICTURE TABLE III American Wire Gauge (B. & S.) No. DiAMETKR IN Circular Mils Ohms per 1000 Ft. No. Diameter in Circular Mils Ohms per 1000 Ft. Mils Millim. Mils Millim. 0000 460.00 11.684 211600.0 .051 19 35.89 .912 1288.0 8.617 000 409.64 10.405 167805.0 .064 20 31.96 .812 1021.5 10.566 00 364.80 9.206 133079.4 .081 21 28.46 .723 810.1 13.323 324.95 8.254 105592.5 .102 22 25.35 .644 642.7 16.799 1 289.30 7.348 83694.2 .129 23 22.57 .573 509.5 21.185 2 257.63 6.544 66373.0 .163 24 20.10 .511 404.0 26.713 3 229.42 5.827 52634.0 .205 25 17.90 .455 320.4 33.684 4 204.31 5.189 41742.0 .259 26 15.94 .405 254.0 42.477 5 181.94 4.621 33102.0 .326 27 14.19 .361 201.5 53.563 6 162.02 4.115 26250.5 .411 28 12.64 .321 159.8 67.542 7 144.28 3.665 20816.0 .519 29 11.26 .286 126.7 85.170 8 128.49 3.264 16509.0 .654 30 10.03 .255 100.5 107.391 9 114.43 2.907 13094.0 .824 31 8.93 .277 79.7 135.402 10 101.89 2.588 10381.0 1.040 32 7.95 .202 63.2 170.765 11 90.74 2.305 8234.0 1.311 33 7.08 .108 50.1 215.312 12 80.81 2.053 6529.9 1.653 34 6.30 .160 39.7 271.583 13 71.96 1.828 5178.4 2.084 35 5.01 .143 31.5 342.443 14 64.08 1.628 4106.8 2.628 36 5.00 .127 25.0 431.712 15 57.07 1.450 3256.7 3.314 37 4.45 .113 19.8 544.287 IG 50.82 1.291 2582.9 4.179 38 3.96 .101 15.7 686.511 17 45.26 1.150 2048.2 5.269 39 3.53 .090 12.5 865.046 18 40.30 1.024 1624.1 6.645 40 3.14 .080 9.9 1091.865 Example. If the resistance of a copper conductor at 95° F. is 48.2 ohms, what would be the resistance of the same conductor at 40° F. ? Solution. In this case i?2 = 48.2, < = 95 — 40 = 55, and from Table II, a = .0022. Substituting these values in the formula /?j = 1 + 0/ we have _ 48.2 48.2 * " 1 + .0022 X 55 1.121 = 43 ohms (approx.) Ans. 43 ohms. Table III gives the resistance of the most common sizes of copper wire according to the American or Brown and Sharpe (B. & S.) gauge. Tlie resistance given is for pure copper wire at a tem- perature of 75° F. or 24° C. The fourth cokimn gives the equiva- lent number of wires each one mil or one-thousandth of an inch in diameter. This is called the size of the wire in circular mil and is etjual to the square of the diameter in mils. The fifth column 244 ELECTRICAL PRINCIPLES 33 gives the ohms per thousand feet and the resistance per mile is found by muUiplying these vakies by 5.28. Ordinary commercial copper has a conductivity of about 95 to 97 per cent of that of pure copper. The resistance of commercial wire is, therefore, about 3 to 5 per cent greater than the values given in Table III. The resistance for any metal other than copper may be found by multiplying the resist- ance given in Table III by the ratio of the specific resistance of the given metal to the specific resistance of copper. Table IV gives the size of the English or Birmingham wire gauge. The B. & S. is, however, much more frequently used in this country. The Brown and Sharpe gauge is a little smaller than the Birmingham for corresponding numbers. TABLE IV Stubs' or Birmingham Wire Gauge (B. W. Q.) No. Diameter in | No. Diameter in | No. Diameter in | Mils Millim. Mils Millim. Mils Millim. 0000 454 11.. 53 S 1G5 4.19 18 49 1.24 00 380 9. 05 10 134 3.40 20 35 0.89 1 300 7.02 12 109 2.77 24 22 0.55 4 238 G.04 14 83 2.11 30 12 0.31 6 203 5.16 16 65 1.65 30 4 0.10 EXAMPLES FOR PRACTICE L Wliat is the resistance of an annealed silver wire 90 feet long and .2 inch in diameter at 32° F.? Ans. .02+ ohm. 2. Wliat is the resistance of 300 meters of annealed iron wire 4 millimeters in diameter when at a temperature of 0° C? Ans. 2.31 + ohms. 3. What is the resistance of 2 miles of No. 27 (B. & S.) pure copper wire at 75° F.? Ans. 565+ ohms. 4. The resistance of a piece of cop})er wire at 32° F. is 3 ohms. Wliat is its resistance at 49° F.? Ans. 3.11+ ohms. 5. The resistance of a copptr wire at 52° F. is 7 ohms, ^^^lat is its resistance at 32° F.? Ans. C.70+ ohms. 6. What is the resistance of 496 ft. of No. 10 (B. & S.) pure copper wire at 45° F.? Ans. .483+ ohms. 245 34 THE MOTION PICTURE TABLE V Primary Cells, Electromotive Force, Resistance, Etc. Name OF Cell Volta (WoUas- ton, etc.) Smee Law Poggen- dorff (Grenet) Poggen- dortr (Grenet) two fluid Grove Bunsen Leclanch^ Lalande Lalande- Chaperon Upward Fitch Papst Obach (dry) Daniell (Meidin- ger Min- otto, etc.) De la Rue Marie Davy Clark (Standard! Anode Weston Zinc Zmc Zinc Zinc Zinc Zinc Zinc Zinc Zinc Zinc Iron Zinc Zinc Zinc Zinc Zinc Cadmium Kathode Copper Platinized Silver Carbon Graphite (Carbon) Graphite (Carbon) Platinum Graphite (Carbon) Graphite (Carbon) Graphite (Carbon) Graphite (Carbon) Graphite (Carbon) Graphite (Carbon) Graphite (Carbon) Copper Silver Graphite (Carbon) Mercury Mercury Excitant Solution of Sulphuric Acid (HjSO,) Solution of Sulphuric Acid (H^SO,) Solution of Sulphuric Acid (H.SO,) Solution of Sulphuric Acid (H2SO4) Saturated Solu- tion of Potas- sium Dichro- mate and Sulphuric Acid Sulphuric Acid dilute (HjSO^) Stilphuric Acid dilute (H2SO4) Ammonium Chloride (NH^Cl) Caustic Potash or Potassium Hydrate (KOH) Zinc Chloride (ZnCla) Ammoniiun Chloride (NH^Cl) Ferric Chloride (FejClg) Ammonium Chloride (NH.Cl) in Calcium Sul- phate (CaSO^) Zinc Sulphate (ZnSO.) Ammonium Chloride Sulphuric Acid dilute (H2SO4) Zinc Sulphate (ZnSo4) Cadmium Sul- Mercurous Sul- ) III""': -A p hate (CdS04) I h ate(Hg2S04) *At 15 degrees centigrade or 59 degrees Fahrenheit. Depolarizer None None None Potassium Dichromate (KoCrjO.) None Separate Nitric Acid (HNOJ Nitric Acid E. M. F IN Volts 1 to 0.5 2.1 1.96 l.Stol.98 Internal Resist- ance IN Ohms 0.5 .001 to .08 0.1 to 0.12 Chromic Acid Manganese Dioxide (MnO.,) Cupric Oxide Chlorine (CI) Sodium&Potas- sium Chlorates (NaC10,-f KCIO3) UFe,Cl ) Manganese Dioxide (MnOJ Copper Sul- phate (CuSO.) Silver Chloride (AgCl) Paste of Sul- phateofMercurj- (IIg2S04) Mercurous Sul- phate(Hg,SO^) 0.08 to o. 11 1.8 10. 1 to 0.12 1.4 to 1.6 1.13 to 1.15 0.8 to 0.9 2.0 1.1 1.3 1.079 1.03 to 1.42 1 52 1.434* 1.025 2 to 5 0.4 to 0.6 0.75 to 1 0.3 to 0.5 246 ELECTRICAL PRINCIPLES TABLE V (Continued) 35 Name OF Cell Von Helmholtz Chromic Acid single fluid Fuller GaifiFe Maiche Niaudet Schans- chiefE Skrivan- off Anode Zinc Zinc Zinc Zinc Zinc scraps in bath of Mercury Zinc Zinc Zinc Kathode Mercurv Graphite (Carbon) Graphite (Carbon) Silver Platinized Carbon Graphite (Carbon) Graphite (Carbon) Silver Excitant Zinc Cliloride (ZnClJ Sulphuric and Chromic Acids, dilute mixed Sulphuric Acid (H,SO,) Zinc Chloride (ZnCU) Common Salt Solution i. e. Sodium Chlo- ride (NaCl) Common Salt Sohuion i. e. Sodium Chlo- ride (NaCl) Mercurial Solution Caustic Potash or Potassium Hydrate (KOH) Depolarizer Mercurous Chloride (Hg,CL) None Separate Potassium Bichromate (K.Cr^O,) Silver Chloride (AgCl) None Separate Chloride of Calcium (Lime) (CaClj) None Separate Chloride of Silver (AgCl) E. M. F IN VOI.TS 2.2 1.25 l.OtO l.f Internai. Resist- ance IN OhM8 .016 to .OS 0.5 to 0.7 0.5 to O.G 1 to 2 5 to G 0.05to0.75 Resistances in last column measured in cells standing 6" X 4" Table V discloses among other data the resistance of various primary cells. The resistance of a circuit of which a battery forms a part is made up of the external resistance, or the resistance of out- side wires and connections, and the internal resistance, or the resist- ance of the battery itself. The terms anode and kathode appearing in the second and third columns, are commonly used with reference to electrolysis but may also be applied to primary cells. The current pavS-Sjes from the anode to the kathode through the cell and, therefore, with reference to the cell itself, the anode may be considered the posi- tive element and the kathode the negative element. In regard to the outside circuit, however, the current passes, of course, from the kath- ode to the anode, and hence with reference to the outside circuit the kathode is positive and the anode negative; ordinarily, the external circuit is considered. As the anode of almost all primary cells is zinc it may readily be remembered that the current pa.sses from the other element to the zinc through the external circuit. 247 36 ' THE MOTION PICTURE APPLICATIONS OF OHM'S LAW Ohm's law is one of the most important and most used laws of electricity. Current is directly 'proportional to the electromotive force and inverschj proportional to the resistance. That is, if the electromotive force applied to a circuit is increased, the current will be increased in the same proportion, and if the resistance of a circuit is increased, then the current will be decreased proportionally. Likewise a decrease in the electromotive force causes a proportional decrease in current, and a decrease in resistance causes a proportional increase in current. The current depends only upon the electromotive force and resistance and in the manner expressed by the above simple law. The law may be expressed algebraically as follows electromotive force current a ^ resistance The units of these quantities, the ampere, volt, and ohm, have been so chosen that an electromotive force of 1 volt applied to a resistance of 1 ohm, causes 1 ampere of current to flow. Ohm's law may, therefore, be expressed by the equation R where C is the current in amperes, E the electromotive force in volts, and R the resistance in ohms. It is, therefore, evident that if the electromotive force and re- sistance are knowm the current may be found, or if any two of the three quantities are known the third may be found. If the current and resistance are known the electromotive force may be found from the formula E = RC and if the current and electromotive force are known, the resist- ance may be found from the formula C Simple Applications. The following examples are given to illustrate the simplest applications of Ohm's law: 248 ELECTRICAL PRINCIPLES 37 Example. If the e. m. f. applied to a circuit is 4 volts and its resist- ance is 2 ohms, what current will flow? Solution. By the formula for current ^ E 4 C = — = — = 2 amperes R 2 ^ Ans. 2 amperes. Example. What voltage is necessary to cause a current of 23 amperes to flow through a resistance of 820 ohms? Solution. By the formula for e. m. f., E ^ RC = 820 X 23 = 18,860 volts. Ans. 18,860 volts. Example. The e. m. f. applied to a circuit is 110 volts, and it is desired to obtain a current of .6 ampere. What should be the resistance of the circuit? Solution. By the formula for resistance E 110 R =—r = = 183. + ohms. C .6 Ans. 183+ ohms. Series Circuits. A circuit made up of several parts all joined in scries with each other, is called a series circuit and the resistance of the entire circuit is, of course, the sum of the separate resistances. In calculating the current in such a circuit the total resistance must first be obtained, and the current may then be found by dividing the applied or total e. m. f. by the total resistance. This is expressed by the formula E C = R, + R + R^-^ etc. Example. Three resistance coils are connected in series with each other and have a resistance of 8, 4 and 17 ohms respectively. What current will flow if the e. m. f. of the circuit is 54 volts? Solution. By the preceding formula ^ E 54 54 1.8+ amperes R^ + R2 + R3 8 + 4 + 17 29 Ans. 1.8+ amperes. Example. Six arc lamps, each having a resistance of 5 ohms, are con- nected in series with each other and the resistance of the connecting wires and other apparatus is 3.7 ohms. What must be the pre.ssure of the circuit to give a desired current of 9.6 amperes? Solution. The total resistance of the circuit is 72 — (6 X 5) + 3.7 = 33.7 ohms and the current is to be C = 9.G amperes. Hence, by the formula for e. m. f., E = RC = 33.7 X 9.6 = 323.+ volts. Ans. 323+ volts. 249 38 THE MOTION PICTURE Ex.\MPLE, The current passing in a certain circuit was 12 amperes and the e. m. f. was 743 volts. The circuit was made up of 4 sections all connected in series, and the resistance of three sections was 16, 9, and 26 ohms, respect- ively. What was the resistance of the fourth section? Solution. Let x = the resistance of the fourth section, then i? = 16 + 9 + 26 + X = 51 + X, C = 12, and E = 743. By the formula for resistance R E or, 51 + X 743 72^ = 61.9 ohms (approx.) If 51 + X = 61.9 we have, by transposing 51 to the other side of the equation X = 61.9 - 51 = 10.9 ohms Ans. 10.9 ohms. Example. A current of 54 amperes flowed through a circuit when the e. m. f. was 220 volts. What resistance should be added in series with the circuit to reduce the current to 19 amperes? Solution. The resistance in the first case was 220 R = = 4.07 ohms (approx.) The resistance in the second must be 220 R 19 11.58 ohms (approx.) The required resistance to insert in the circuit is the difference of these two resistances, or 11.58 — 4.07 = 7.51 ohms. Ans. 7.51 ohms. Fall of Potential in a Circuit. Fls. 28 illustrates a series circuit in which the resistances A, B, C, D, and E are connected in series WVW^ WV\AV sA'VvVW^ Fig. 28. Baltpry Circuit Through Resistances in Series with each other and with the source of electricity. If the e. m. f. is known, the current may be found by dividing the e. m. f. by the sum of all the resistances. Ohm's law may, however, be applied to any 250 H g .2 Q. t ** S - W o ^ S "s 2- H So 0, ^5 fe r 3 o .-5 £5 ^^ O aS w P s ELECTRICAL PRINCIPLES 39 part of a circuit separately, as well as to the complete circuit. Sup- pose the resistances of A, B, C, D, and E are 4, 3, 6, 3, and 4 ohms, respectively, and assume that the source has no resistance. Suppose the current flowing to be 12 amperes. The e. m. f. necessary to force a current of 12 amperes through the resistance ^ of 4 ohms is, by applying Ohm's law, equal to£=7?C=4Xl2 = 48 volts. Herice, between the points a and b outside of the resistance A, there must be a difference of potential of 48 volts to force the current through this resistance. Also to force the same current through B, the volt- age necessary is 3 X 12 = 36. Similarly, for each part C, D, and E, there are required 72, 36, and 48 volts, respectively. As 48 volts are necessary for part A and 36 volts for part B, it is e\'ident that to force the current through both parts a differ- ence of potential of 48 + 36 = 84 volts is required; that is, the voltage between the points a and c must be 84 volts. For the three parts A, B, and C, 48 + 36 + 72 = 156 volts are necessary, and for the entire circuit, 240 volts must be applied to give the current of 12 amperes. From the above it is evident that there is a gradual fall of potential throughout the circuit, and if the voltage between any two points of the circuit be measured, the e. m. f. obtained would depend upon the resistance included between these two points. For example, the voltage between points b and d would be found to be 72 + 36 = 108 volts, or between d and c, 36 volts, etc. From the preceding it is apparent that the fall of potential in a part of a circuit is equal to the current multiplied by the resistance of that part. This gradual fall of potential, or droj) as it is commonly called, throughout a circuit, enters into the calculations for the size of conduct- ors or mains supplying current to distant points. Tlie resistances of the conductors cause a certain drop in transmitting the current, depending upon their size and length, and it is, therefore, necessary that the voltage of machines at the supply station shall be great enough to give the voltage necessary at the receiving stations as well as the additional voltage lost in the conducting mains. For example, in Fig. 28 the voltage necessary between the points e and h is 144 volts, l)ut to give this voltage the source must supply in addition the voltage lost in parts .1 and E, which equals 96 volts. 251 40 THE MOTION PICTURE Ex,\MPLE. The voltage required by 17 arc lamps connected in series is 782 volts and the current is 6.6 amperes. The resistance of the connecting wires is 7 ohms. What must be the e. m. f. applied to the circuit? Solution. The drop in the connecting wires isE = RC = 7X 6.6 = 46.2 volts. The e.m.f. necessary is, therefore, 782 + 46.2 = 828.2 volts. Ans. 828.2 + volts. Example. The source of e. m. f. supplies 114 volts to a circuit made up of mcandescent lamps and conducting wires. The lamps require a voltage of 110 at their terminals, and take a current of 12 amperes. What should be the resistance of the conducting wires in order that the lamps will receive the necessary voltage? Solution. The allowable drop in the conducting wires is 114 — 110 = 4 volts. The current to pass through the wires is 12 amperes. Hence, the resistance must be E ^ R = = ■ — = .33 4- ohms C 12 Ans. .33 ohms. Divided Circuits. ^Mien a circuit divides into two or more parts, it is called a divided circuit and each part will transmit a portion of the current. Such a circuit is illustrated in Fig. 29, the two branches being represented by h and c. The current passes from the positive pole of the battery through a and then divides; part of the current passing -]L+ Fig. 29. Divided Circuits through h and part througli c. The current then unites and passes through d to the negative pole of the battery. The part c may be considered as the main part of the circuit and 6 as a by-pass about it. A branch which serves as a by-pass to another circuit is called a shunt circuit, and the two branches are said to be connected in farcdlcl. In considering the passage of a current through a circuit of this sort, it may be necessary to determine how much current will pass through one branch and how much through the other. Evidently this will depend upon the relative resistance of the two branches, and more current will pass through the branch offering the lesser 252 ELECTRICAL PRINCIPLES 41 resistance than through the branch having the higher resistance. If the two parts have equal resistances, then one-half of the total cur- rent will pass through each branch. If one branch has twice the resistance of the other, then only one-half as much of the total cur- rent will pass through that branch as through the other; that is, one- third of the total current will pass through the first branch and the remaining two-thirds will pass through the second. The relative strength of current in the two branches luill he in- versely proportional to their resistances, or directly proportional to their conductances. Suppose the resistance of one branch of a divided circuit is r^, Fig, 30, and that of the other is r^. Then by the preceding law Also, and current m r^ : current m r^ current in r, : total current : : r^ : r, -\- r. current in r, : total current : : r,: r, i- r. Let C represent the total current, i^ the current through the resistance r^ and i^ the current through the resistance r^. Then the » Fig. 30. Joint Resistance of a Divided Circuit two preceding proportions are expressed by the following formulas Cr, . . Cr, 2j = and ?2 = r, + r3 r, + r^ Example. The total current passing in a circuit is 24 amperes. The circuit divides into two branches having resistances of 5 and 7 ohms, respect- ively. What is the current in each branch? Solution. In this case C = 24, r^ = 5, and r^ = 7. Substituting these values in the above formulas, we have ^H 24 X 7 I = — = = 14 amperes ^ '"i + '"2 5 + 7 -^'"1 24 X 5 and z, = ■ * — = = 10 amperes ^ T^\r^_ 7 + 7 j In .5 ohm branch, 14 amperes. " " ohm branch, 10 amperes. j In h '• ] In 7 253 42 THE MOTION PICTURE Joint Resistance of Divided Circuits. As a divided circuit offers t^vo paths to the current, it follows that the joint resistance of the tAvo branches will be less than the resistance of eitlier branch alone. The ability of a circuit to conduct electricity is represented by its conductance, which is the reciprocal of resistance; and the conduct- ance of a divided circuit is equal to the sum of the conductances of its parts. For example, in Fig. 30, the conductance- of the upper branch equals — and that of die lower branch equals — . If R represents r T ' 1 '2 the joint resistance of the two parts then the joint conductance equals 1 1 ^_^_^+r. R Tj r^ r^r^ Having thus obtained the joint conductance, the joint resist- ance is found by taking the reciprocal of the conductance, that is, R = ^ + ^2 This formula may be stated as follows; The joint resistance of a divided circuit is equal to the product of the two separate resistances divided hy their sum. For example, suppose the resistance of each branch to be 2 ohms. The conductance of the circuit will be, — = — + — = 1 , and hence R = I ohm R 2 2 Also by the preceding formula R = = 1 ohm 2 + 2 The resistance of a divided circuit in which each branch has a resistance of 2 ohms is, therefore, 1 ohm. Example. The resistances of two separate conductors are 3 and 7 ohms, respectively. What would be their joint resistance if connected in parallel? Solution. In this case r. = 3 and rj = 7, hence, by the formula r. 3X7 R = = 2.1 ohms. 3+7 Ans. 2.1 ohms. 254 ELECTRICAL PRINCIPLES 43 Suppose, as illustrated in Fig. 31, the conductors having resistances equal to r^, r-j, and r^, respectively, are connected in parallel. The joint total conductance will then be equal to 1 _ TVl+Il '"3 + '"l ^2 1 1 1 = — -)- — h ^1 '-2 and as the joint resistance is the reciprocal of the joint conductance, the joint resistance R of the three branches is expressed by the formula R = ro i\ + r, r„ + r, r. 12 Example. What is the joint resistance when connected in parallel, of three wires whose respective resistances are 41, 52, and 29 ohms, respectively? Solution. In this case r^ = 41, rj = 52, and rg = 29. Hence, by the preceding formula, ^ 41 X 52 X 29 R = — = 12.8+ ohms. 52 X 29 + 41 X 29 + 41 X 52 Ans. 12.8+ ohms. In general, for any number of conductors connected in parallel, the joint resistance is found by taking the reciprocal of the sum of the reciprocals of the separate resistances. Fig. 31. Triply Di\-ided Circuit Example. A circuit is made up of five wires connected in parallel, and their separate resistances are respectively 12, 21, 28, 8, and 42 ohms. What is the joint resistance? Solution. The sum of the conductances is- 1 1 1 1 1 _ 53 U "^ 2T "*" 28 "^ 8 42 ~ 168 Hence the joint resistance equals 168 ie = =3.1+ ohms 53 Ans. 3.1 + ohms. If the resistance of each branch is known and also the poten- tial difference between the points of union, then the current in each branch may be found by applying Ohm's law to each branch sepa- rately. For example, if this potential difference were 96 volts, 255 44 THE MOTION PICTURE and the separate resistances of the 4 branches were 8, 24, 3, and 48 ohms, respectively, then the current in the respective branches would be 12, 4, 32, and 2 amperes, respectively. If the current in each branch is known, and also the potential difi'erence between the points of union, then the resistance of each branch may likewise be found from Ohm's law. The following examples are given to illustrate the application of the preceding principles. EXAMPLES FOR PRACTICE 1. Two conductors having resistances of 71 and 19 ohms, respectively, are connected in parallel, and the total current pass- ino' in the circuit is 37 amperes. WTiat current passes in the con- ductor whose resistance is 71 ohms? Ans. 7.8+ amperes. 2. ^^^lat is the joint resistance of two wires connected in parallel if their separate resistances are 2 and 8 ohms, respectively? Ans. 1.6 ohms. 3. AMiat is the joint resistance of three wires when connected in parallel, whose separate resistances are 5, 7, and 9 ohms, re- spectively? Ans. 2.2+ ohms. 4. Three wires, the respective resistances of which are 8, 10, and 20 ohms, are joined in parallel. ^Vllat is their joint resistance? Ans. 3.6+ ohms. 5. Four wires are joined in parallel, and their separate re- sistances are 2, 4, 6, and 9 ohms, respectively. What is the joint resistance of the conductor thus formed? Ans. .97+ ohms. WIRING METHODS PLANNING AN INSTALLATION The first step in planning a wiring installation, is to gather all tne data which will affect either directly or indirecdy the system of wiring and the manner in which the conductors are to be installed. The data will include: Kind of building; construction of building; space available for conductors; source and system of electric-current supply; and all details which will determine the method of wiring to be employed. These last items materially affect the cost of the work, and are usually determined by the character of the building and by commercial considerations. J5G ELECTRICAL PRINCIPLES 45 Method of Wiring. In a modern fireproof building, the only system of wiring to be recommended is that in which the conductors are installed in rigid conduits ; although, even in such cases, it may be desirable, and economy may be effected thereby, to install the larger feeder and main conductors exposed on insulators using weather- proof slow-burning wire. This latter method should be used, how- ever, only where there is a convenient runway for the conductors, so that they will not be crowded and will not cross pipes, ducts, etc., and also will not have too many bends. Also, the local inspection authori- ties should be consulted before using this method. For mills, factories, etc., wires exposed on cleats or insulators are usually to be recommended, although rigid conduit, flexible con- duit, or armored cable may be desirable. In finished buildings, and for extensions of existing outlets, where the wiring could not readily or conveniently be concealed, moulding is generally used, particularly where cleat wiring or other exposed methods of wiring would be objectionable. However, as has already been said, moulding should not be employed where there is any liability to dampness. In finished buildings, particularly where they are of frame con- struction, flexible steel conduits or armored cable are to be recom- mended. Wliile in new buildings of frame construction, knob and tube wiring is frequently employed, this method should be used only where the question of first cost is of prime importance. Wliile ar- mored cable will cost approximately 50 to 100 per cent more than knob and tube wiring, the former method is so much more perma- nent and is so much safer that it is strongly recommended. Systems of Wiring. The system of wiring — that is, whether the two-wire or the three-wire system shall be used — is usually deter- mined by the source of supply. If the source of supply is an isolated plant, with simple two-wire generators, and with little possibility of current being taken from the outside at some future time, the wiring in the building should be laid out on the two-wire system. If, on the other hand, the isolated plant is three-wire (having three-wire generators, or two-wire generators with balancer sets), or if the cur- rent is taken from an outside source, the wiring in the building should be laid out on a three-wire system. 257 46 THE MOTION PICTURE It very seldom happens that current supply from a central station is arranged with other than the three-wire system inside of buildings, because, if the outside supply is alternating current, the transformers are usually adapted for a three-wire system. For small buildings, on the other hand, where there are only a few lights and where there would be only one feeder, the two-wire system is used. As a rule, however, when the current is taken from an outside source, it is best to consult the engineer of the central station supplying the current, and to conform with his wishes. As a matter of fact, this should be done in any event, in order to ascertain the proper voltage for the lamps and for the motors, and also to ascertain whether the central station will supply transformers, meters, and lamps, for, if these are not thus supplied, they should be included in the contract for the wiring. Location of Outlets. A set of plans, including elevation and details, if any, and showing decorative treatment of the various rooms, should be obtained from the architect. A careful study should then be made by the architect, the owner, and the engineer, or some other person qualified to make recommendations as to illumination. The location of the outlets will depend: First, upon the decorative treatment of the room, which determines the aesthetic and architect- ural effects; second, upon the type and general form of fixtures to be used, which should be previously decided on; third, upon the tastes of the oA\niers or occupants in regard to illumination in general, as it is found that tastes vary widely in regard to amount and kind of illumination. The location of the outlets, and the number of lights required at each, having been determined, the outlets should be marked on the plans. The architect should then be consulted as to the location of the centers of distribution, the available points for the risers or feeders, and the available space for the branch circuit conductors. In regard to the rising points for the feeders and mains, the fol- lowing precautions should be used in selecting chases: The space should be amply large to accommodate all the feeders and mains likely to rise at that given point. This seems trite and unnecessary but it is the most usual trouble with chases for risers. Formerly architects and builders paid little attention to the requirements for chases for electrical 258 ELECTRICAL PRINCIPLES 47 work; but in these later days of 2-inch and 2vV-inch conduit, they realize that these pipes are not so invisible and mysterious as the force they serve to dis- tribute, particularly when twenty or more such conduits must be stowed away in a building where no special provision has been made for them. If possible, the space should be devoted solely to electric wiring. Steam pipes are objectionable on account of their temperature; and these and all other pipes are objectionable in the same space occupied by the electrical conduits, for if the space proves too small, the electric conduits are the first to be crowded out. The chase, if possible, should be continuous from the cellar to the roof, or as far as needed. This is necessary in order to avoid unnecessary bends or elbows, which are objectionable for many reasons. In similar manner, the location of cut-out cabinets or distributing centers should fulfill the following requirements: They should be accessible at all times. They should be placed sufficiently close together to prevent the circuits from being too long. They should not be placed in too prominent a position, as that is objec- tionable from the architect's point of view. They should be placed as near as possible to the rising chases, in order to shorten the feeders and mains supplying them. Finished F^ooi^ Fig. 32. Running Conductors Concealed Under Floor in Fireproof Building Having- determined the system and method of wiring, the location of outlets and distributing centers, the next step is to layout the branch circuits supplying the various outlets. Before starting to lay out the branch circuits, a drawing showing the floor construction, and shoTvang the space between the top of the beams and girders and the flooring, should be obtained from the archi- tect. In fireproof buildings of iron or steel construction, it is almost the invariable practice, where the work is to be concealed, to run the conduits over the beams, under the rough flooring, carrying them between the sleepers when running parallel to the sleepers, and notch- ing the latter when the conduits run across them, Fig. 32. In wooden 259 48 THE MOTION PICTURE frame buildings, the conduits run parallel to the beams and to the furring, Fig. 33; they are also sometimes run below the beams. In the latter case the beams have to be notched, and this is allowable only in certain places, usually near the points where the beams are sup- ported. The architect's drawing is, therefore, necessary in order that the location and course of the conduits may be indicated on the plans. The first consideration in laying out the branch circuit is the number cf outlets and nuinhcr cf lights to be wired on any one branch circuit. The Rules of the National Electric Code require that "no set of incandescent lamps requiring more than 660 watts, whether grouped on one fixture or on several fixtures or pendents, will be dependent on one cut-out." \Miile it would be possible to have branch circuits supplying more than 660 watts, by placing various cut-outs at different points along the route of the branch circuit, so as to subdi\ade it into small sections to comply with the rule, this method is not recommended, except in certain cases, for exposed wiring in factories or mills. As a nde, the proper method is to have the cut-outs located at the center ri-nisVied rioor-^ Stud or Wall T f^I^n^ • P^Hi-'-.-.-: IJ^V;!-'-';^,' ]'■ <,■ t-^rs::^, ^ Wooflen Bea-TTi Furring Strips -B^wr i'*^'.' Rough riooring / Condu.it ■I* •'• f'<--^' ^ Lathing / ^Plastering Stud or Wall Fig. 33. Running Conductors Concealed Under Fl oor in Wooden Frame Building of distribution, and to limit each branch circuit to 660 watts, which corresj)onds to twelve or thirteen 50-watt lamps, twelve being the usual limit. Attention is called to the fact that the inspectors usually allow 50 watts for each socket connected to a branch circuit; and although 8-candle-power lamps may be placed at some of the outlets, the inspectors hold that the stiindard lamp is approximately 50 watts, and for that reason there is always the likelihood of a lamp of that capacity being used, and their inspection is based on that assumption. Therefore, to comply with the requirements, an allowance of not more than twelve lamps per branch circuit should be made. 260 I ELECTRICAL PRINCIPLES 49 In ordinary practice, however, it is best to reduce this number still further, so as to make allowance for future extensions or to in- crease the number of lamps that may be placed at any outlet. For this reason, it is wise to keep the number of the outlets on a circuit at the lowest point consistent with economical wiring. It has been proven by actual practice, that the best results are obtained by limit- ing the number to five or six outlets on a branch circuit. Of course, where all the outlets hav^e a single light each, it is frequently neces- sary, for reasons of economy, to increase this number to eight, ten, and, in some cases, twelve outlets. Now, as to the course of the circuit work, little need be said, as it is largely influenced by the relative position of the outlets, cut- outs, switches, etc. Between the cut-out box and the first outlet, and between the outlets, it will have to be decided, however, whether the circuits shall run at right angles to the walls of the building or room, or whether they shall run direct from one point to another, irrespective of the angle they make to the sleepers or beams. Of course, in the latter case, the advantages are that the cost is some- what less and the number of elbows and bends is reduced. If the tubes are bent, however, instead of using elbows, the difference in cost is usually very slight, and probably does not compensate for the disadvantages that would result from running the tubes diagonally. As to the number of bends, if branch circuit work is properly laid out and installed, and a proper size of tube used, it rarely happens that there is any difference in "pulling" the branch circuit wires. It may happen, in the event of a very long nm or one having a large number of bends, that it might be advisable to adopt a short and more direct route. Up to this time, the location of the distribution centers has been made solely with reference to architectural considerations; but they must now be considered in conjunction with the branch circuit work. It frequently happens that, after nmning the branch circuits on the plans, we find, in certain cases, that the position of centers of distribution may be changed to advantage, or sometimes certain groups may be dispensed with entirely and the circuits nm to other points. We now see the wisdom of ascertaining from the architect where cut-out groups may be located, rather than selecting particular points for their location. 261 50 THE MOTION PICTURE As a rule, wherever possible, it is wise to limit the length of each branch circuit to 100 feet; and the number and location of the dis- tributing centers should be determined accordingly. It may be found that it is sometimes necessary and even desirable to increase the limit of length. One instance of this may be found in hall or corridor lights in large buildings. It is generally desirable, in such cases, to control the hall lights from one point; and, as the number of lights at each outlet is generally small, it would not be economical to run mains for sub-centers of distribution. Hence, in instances of this character, the length of runs will frequently exceed the limit named. In the great majority of cases, however, the best results are obtained by limiting the runs to 90 or 100 feet. There are several good reasons for placing such a limit on the length of a branch circuit. To begin with, assuming that we are going to place a limit on the loss in voltage (drop) from the switchboard to the lamp, it may easily be proven that up to a certain reasonable limit it is more economical to have a larger number of distributing centers and shorter branch circuits, than to have fewer centers and longer circuits. It is usual, in the better class of work, to limit the loss in voltage in any branch circuit to approximately one volt. As- suming this limit (one volt loss), it can readily be calculated that the number of lights at one outlet which may be connected on a branch circuit 100 feet long (using No. 14 B. & S. wire), is four; or in the case of outlets having a single light each, five outlets may be con- nected on the circuit, the first being 60 feet from the cut-out, the others being 10 feet apart. These examples are selected simply to show that, if the branch circuits are much longer than 100 feet, the loss must be increased to more than one volt, or else the number of lights that may be con- nected to one circuit must be reduced to a very small quantity, pro- vided, of course, the size of the wire remains the same. Either of these alternatives is objectionable — the first, on the score of regulation; and the second, from an economical standpoint. If, for instance, the loss in a branch circuit with all the lights turned on is four volts (assuming an extreme case), the voltage at which a lainj) on that circuit burns will vary from four volts, depending on the innnbcr of liglits burning at a time. This, of course, will cause the lanij> to burn below candle-power when all the lamps are turned on, 262 ELECTRICAL PRINCIPLES 51 or else to diminish its life by burning above the proper voltage when it is the only lamp burning on the circuit. Then, too, if the drop in the branch circuits is increased, the sizes of the feeders and the mains must be correspondingly increased (if the total loss remains the same), thereby increasing their cost. If the number of lights on the circuit is decreased, we do not use to good advantage the available carrying capacity of the wire. Of coarse, one solution of the problem would be to increase the size of the wire for the branch circuits, thus reducing the drop. This, however, would not be desirable, except in certain cases where there were a few long circuits, such as for corridor lights or other special control circuits. In such instances as these, it would be better to increase the sizes of the branch circuit to No. 12 or even No. 10 B. &:. S. gauge conductors, than to increase the numbers of centers of distribution for the sake of a few circuits only, in order to reduce the number of lamps (or loss) within the limit. The method of calculating the loss in conductors has been given elsewhere; but it must be borne in mind, in calculating the loss of a branch circuit suppl}ing more than one outlet, that separate calcu- lations must be made for each portion of the circuit. That is, a calculation must be made for the loss to the first outlet, the length in this case being the distance from the center of distribution to the first outlet, and the load being the total number of lamps supplied by the circuit. The next step would be to obtain the loss between the first and second outlet, the length being the distance between the two out- lets, and the load, in this case, being the total number of lamps sup- plied by the circuit, minvs the number supplied by the first outlet; and so on. The loss for the total circuit would be the sum of these losses for the various portions of the circuits. Feeders and Mains. If the building is more than one story, an elevation should be made showing the height and number of stories. On this elevation, the various distributing centers should be sho\Mi diagrammatically ; and the current in amperes supplied through each center of distribution, should be indicated at each center. The next step is to lay out a tentiitive system of feeders and mains, and to ascertain the load in amperes supplied by each feeder and main. The estimated length of each feeder and main should then be deter- mined, and calculation made for the loss from the switchboard to 263 52 THE MOTION PICTURE each center of distribution. It may be found that in some cases it will be necessary to change the arrangement of feeders or mains, or even the centers of distribution, in order to keep the total loss from the switchboard to the lamps within the limits previously determined. As a matter of fact, in important work, it is always best to lay out the entire work tentatively in a more or less crude fashion, according to the "cut-and-dried" method, in order to obtain the best results, be- cause the entire layout may be modified after the first preliminary layout has been made. Of course, as one becomes mor? experienced and skilled in these matters, the final layout is often almost identical with the first preliminary arrangement. WIRING AN OFFICE BUILDING The building selected as a tj-pical sample of a wiring installation is that of an office building located in Washington, D. C. The figures shown are reproductions of the plans actually used in installing the work. The building consists of a basement and ten stories. It is of fireproof construction, having steel beams with terra-cotta flat arches. The main walls are of brick and the partition walls of terra-cotta blocks, finished with plaster. There is a space of approximately five inches between the top of the iron beams and the top of the finished floor, of which space about 3 inches was available for nmning the electric conduits. The flooring is of wood in the offices, but of concrete, mosaic, or tile in the basement, halls, toilet-rooms, etc. The electric current supply is derived from the mains of the local illuminating company, the mains being brought into the front of the building and extending to a switchboard located near the center of the basement. As the building is a very substantial fireproof structure, the only method of wiring considered was that in which the circuits would be installed in iron conduits. Electric Current Supply. The electric current supply is direct current, two-wire for power, and three-wire for lighting, having a potential of 236 volts between the outside conductors, and 118 volts between the neutral and either outside conductor. Switchboard. On the switchboard in the basement are mounted wattmeters, provided by the local electric company, and the various 264 ELECTRICAL PRINCIPLES 53 switches required for the control and operation of the lighting and power feeders. There is a total of ten triple-pole switches for light- ing, and eighteen for power. An indicating voltmeter and ampere meter are also placed in the switchboard. A voltmeter is provided with a double-throw switch, and so arranged as to measure the poten- tial across the two outside conductors, or between the neutral con- ductor and either of the outside conductors. The ampere meter is arranged with two shunts, one being placed in each outside leg; the shunts are connected with a double-pole, double-throw switch, so that the ampere meter can be connected to either shunt and thus measure the current supplied on each side of the system. Character of Load. The building is occupied partly as a news- paper office, and there are several large presses in addition to the usual linotype machines, trimmers, shavers, cutters, saws, etc. There are also electrically-driven exhaust fans, house pumps, air-compressors, etc. The upper portion of the buikling is almost entirely devoted to offices rented to outside parties. The total number of motors supplied was 55; and the total number of outlets, 1,100, supplying 2,400 incandescent lamps and 4 arc lamps. Feeders and Mains. The arrangement of the various feeders and mains, the cut-out centers, mains, etc., which they supply, are shown diagrammatically in Fig. 34, which also gives in schedule the sizes of feeders, mains, and motor circuits, and the data relating to the cut-out panels. Although the current supply was to be taken from an outside source, yet, inasmuch as there was a probability of a plant being in- stalled in the building itself at some future time, the three-wire system of feeders and mains was designed, with a neutral conductor equal to the combined capacity of the two outside conductors, so that 120-volt two-wire generators could be utilized without any change in the feeders. Basement. The plan of the basement, Fig. 35, shows the branch circuit wiring for the outlets in the basement, and the location of the main s^vitchboa^d. It also shows the trunk cables for the inter- connection system serving to provide the necessary wires for telephones, tickers, messenger calls, etc., in all the rooms throughout the building, as will be described later. To avoid confusion, the feeders were not showni on the basement 265 END AT . s . ^? . SIZE OF WIRE 28° o § llfll'l'lki ' \af 700O00 »5- Ills ^f^ Ml - 15 - P-s! SW.B 136 eOooooo i(Vi«i( « ALL CONDUCTORS IN ONC CONDUIT. < SEPARATE CONDUIT FOR E ACH CONDUCTOR ' N THIS reCDER IS TO BE DIVIDED INTO FOUR (4) CONDUCTORS OF *l 2000000 OM. EACH. EACH CONOUCTCB iS TO BE INSTALLED IN A SEIP* ARATc 3" (Inside oiam]) conduit ^-LifSH-^iNG SUPPLV =P0A'En K separate a" {inside oiAk^coNDuir for each COMCUCTOR z S'JPPUCD I -I zin o> SIZE OF WIRE ii 3 K L. zig oil 1S 0.«1 1.25- D>1 6 " J, -in P -^n n-s 111 " ^ 29 ■* " « BOTH CONDUCTORS IN ONE CONDUIT CUT- OUTS i _1 U. HAS CONNECTIONS FOR | Z < 5 mo It s ^ ^ KNIFE SWITCHES 1 ^'^■''■^■'^- D.P.ST. 1 1 g g s s g S S T=7T i 1 1? (=* ? ? NP ■^ 1 1 * fir 5 /> 4 ^ r o » < a. M § < *- O o a >. si I r ELECTRICAL PRINCIPLES 55 SCHEDULE OF CIRCUITS I d z SUP- PLIED X o z V. OUTLETS SUPPUED TOTAL u 5£8 8 3 Z < z CO O in o -J I A 1 a. 1 1 11 3 bcde^a'hi. ft p> m iklm - 4 ^ E7 nopcr r S n V R fi V.L 1 vza: 3 lO 5a^ A i/11 1 Wc' ? fi \J\\\ d' 1 ft .( it >4 TK. e'fg'Ki' 5 s X .I'V S fi S(3^ A 11 V 1 ft t( it t. ia m' 1 « 13 TT 1 4. «t >. u 14 o'p P .* «• M 15 qV's'fu' .■=; 16 ■•^ 3 17" v' 1 a SQf A IB z' 1 ft ** .. - Wll.-i 1 1 CABLE NO. S RISES TO 2"AHn^ Explanation of Various Symbols used in Fi^s. ^1 toAe Incliusive >- CeiUrj< Chandelier Wall Bracket ©•-- 0— Gooseneck Bracket ° i>^ -- ©-- -Cooper-Mewltt Lamp Cluster © — Floor Outlet ;! ".;:_;;^=r: "j^j" ^ ., .. 1 A Snap Switch* Ht^ — -Junction Boy^ m--- Motor Starter ^ — CutOut Panel C=i--- Interconnection Box e=3— Power Panel — Circuit under Floor ** '* ** above «( oTiCeiUn^ Exposed Service Line under Floor Fig. 35. Wiring an Office Building. Basement Plan Showing Branch Circuit Wiring for Out- lets in Basement, Location of Main Switchboard, and Trunk Cables of the Intercon- n3ction System Providing Wires for Telephone, Ticker, and Messenger Call Servics, etc. 267 56 THE MOTION PICTURE plan, but were described in detail in the specification, and installed in accordance with directions issued at the time of installation. The electric current supply enters the building at the front, and a service switch and cut-out are placed on the front wall. From this point, a two-wire feeder for power and a three-wire feeder for lighting, are run to the main switchboard located near the center of the basement. Owing to the size of the conduits required for these supply feeders, as well as the main feeders extending to the upper floors of the building, the said conduits are run exposed on substantial hangers suspended from the basement to the ceiling. First Floor. The rear portion of the building from the basement through the first floor, and including the mezzanine floor, between the first and second floors, at the rear portion of the building only, is utilized as a press room for several large and heavy modern newspaper presses. The motors and controllers for these presses are located on the first floor. A separate feeder for each of these press motors is run directly from the main switchboard to the motor controller in each case. Empty conduits were provided, ex- tending from the controllers to the motor in each case, intended for the various control wires installed by the contractor for the press equipments. One-half of the front portion of the first floor is utilized as a news- paper ofiice; the remaining half, as a bank. Second Floor. The rear portion of the second floor is occupied as a composing and linot^'pe room, and is illuminated chiefly by means of drop-cords from outlets located over the linotype machines and over the compositors' cases. Separate ^-horse-power motors are provided for each linotype machine, the circuits for the same being run underneath the floor. Upper Floors. The upper floors are similar in all respects with the exception of certain changes in partitions, which are not material for the purpose of illustration or for practical example. The circuit work is suflficiently intelligible from the plan to require no further explanation. Interconnection System. In the interconnection system, the main interconnection box is located in the basement; adjoining this main box is located the terminal box of the local telephone company. A separate system of feeders is provided for the ticker system, as these 268 ELECTRICAL PRINCIPLES 57 conductors require somewhat heavier installation, and it was thought inadvisable to place them in the same conduits with the telephone wires, owing to the higher potential of ticker circuits. A separate interconnection cable rims to each floor, for telephone and messenger call purposes; and a central box is placed near the rising point at each floor, from which nm subsidiary cables to several points symmetrically located on the various floors. From these subsidiary boxes, wires can be run to the various offices requiring telephone or other service. Small pipes are provided to serve as race- ways from office to office, so as to avoid cutting partitions. In this way, wires can be quickly provided for any office in the building without damaging the building in any way whatever; and, as provision is made for a special wooden moulding near the ceiling to accommodate these wires, they can be run around the room without disfiguring the walls. All the main cables and subsidiary wares are con- nected with special interconnection blocks numbered serially; and a schedule is provided in the main interconnection box in the base- ment, which enables any wire originating thereat, to be readily and conveniently traced though the building. All the main cables and subsidiary cables are run in iron conduits. OUTLET=BOXES, CUT=OIJT PANELS, AND OTHER ACCESSORIES Outlet Boxes. Before the introduction of iron conduits, outlet- Fig. 36. Universal and Knock Out Type of Outlet Box Fig. 37. Water-Tight Outlet Box boxes were considered unnecessary, and with a few exceptions were not used, the conduits being brought to the outlet and cut off after the 269 58 THE MOTION PICTURE walls and ceilings were plastered. With the introduction of iron con- duits, however, the necessity for outlet-boxes was realized; and the Rides of the Fire Underwriters were modified so as to require their use. The Rules of the National Electric Code now require outlet-boxes to be used with rigid iron and flexible steel conduits, and with armored cables. A portion of the rule requiring their use is as follows : All interior conduits and armored cables must be equipped at every outlet with an approved outlet-box or plate. Outlet-plates must not be used where it is practicable to install outlet- boxes. In buildings already constructed, where the conditions are such that neither outlet-box nor plate can be installed, these appliances may be omitted by special permission of the inspection department having jurisdiction, pro- viding the conduit ends are bushed and secured. Fig. 38. Types of Floor Outlet Boxes Fig. 39. Fig. 36 shows a typical form of outlet-box for bracket or ceiling outlets of the universal type. WTien it is desired to make an opening for the conduits, a blow from a hammer will remove any of the weak- ened portion of the wall of the outlet-box, as may be required. This form of outlet-box is frequently referred to as the knock-out type. Other forms of outlet-boxes are made with the openings cast in the box at the required points, this class being usually stronger and better made than the universal type. The advantages of the universal type of outlet-box are that one form of box will serve for any ordinary conditions, the openings being made according to the number of conduits and the directions in which they enter the box. Fig. 37 shows a waterproof form of outlet-box used out of doors, or in other places where the conditions require the use of a water- tight and waterproof outlet-box. It will be seen in this case, that the box is threaded for the con- 270 ELECTRICAL PRINCIPLES 59 duits, and that the cover is screwed on tightly and a flange provided for a rabber gasket. Figs. 38 and 39 show water-tight floor boxes which are for outlets located in the floor. A\niile the rules do not require that the floor outlet Fig. 40. Conduit Bushing box shall be water-tight, it is strongly recommended that a water- tight outlet be used in all cases for floor connections. In this case also, the conduit opening is threaded, as well as the stem cover through which the extension is made in the conduit to the desk or table. ^Mien the floor outlet connection is not required, the stem cover may be removed and a flat blank cover be used to replace the same. There is hardly any limit to the number and variety of makes of outlet-boxes on the market, adapted for ordinary and for special conditions; but the types here illustrated are characteristic and typ- ical forms. Bushings. The Rules of the National Electric Code require that conduits entering junction-boxes, outlet-boxes, or cut-out cabinets Fig. 41. Lock-Nut tii»f»-if Fig. 42. Panel-Box Terminal Bushing shall be provided with approved bushings, fitted to protect the wire from abrasion. Fig. 40 shows a tj^ical form of conduit bushing. This busliing is screwed on the end of the conduit after the latter has been intro- duced into the outlet-box, cut-out cabinet, etc., thereby forming an 271 60 THE MOTION PICTURE insulated orifice to protect the wire at the point where it leaves the conduits, and to prevent abrasion, grounds, short circuits, etc. A lock-nut. Fig. 41, is screwed on the threaded end of the conduit before the conduit is placed in the outlet-box or cut-out cabinet, and this lock-nut and bushing clamp the conduit securely in position. Fig. 42 shows a terminal 43 Copper-Tipped Fuse Link ^ushiug for pancl-boxcs uscd for flexible steel conduit or armored cable. The Rules of the National Electric Code require that the metal of conduits shall be permanently and effectually grounded, so as to insure a positive connection for grounds or leaking currents, and in order to provide a path of least resistance to prevent the current from finding a path through any source which might cause a fire. At outlet-boxes, the conduits and gas pipes must be fastened in such a Fig. 44. Edison Fuse-Plug Fig. 45. Porcelain Cut-Out Block manner as to insure good electrical connection ; and at centers of dis- tribution, the conduits should be joined by suitable bond wires, pref- erably of copper, the said bond wires being connected to the metal <^- % Fig. 46. Enclosed or "Cartridge" Fuse structure of the building, or, in case of a building not having an iron or steel structure, being grounded in a permanent manner to water or gas-piping. Fuse=Boxes, Cut=Out Panels, etc. From the very outset, the necessity was apparent of having a protective device in circuit with the conductor to protect it from overload, short circuits, etc. For this purpose, a fusible metal having a low melting point was em- 272 ELECTRICAL PRINCIPLES 61 ployed. The form of this fuse has varied greatly. Fig. 43 shows a characteristic form of what is knowTi as the link fuse with copper terminals, on which is stamped the capacity of the fuse. Fig. 47. Section of Enclosed Fuse The form of fuse used probably to a greater extent than any other, although it is now being superseded by other more modern forms, is that known as the Edison fuse-plug, shown in Fig. 44. A porcelain cut-out block used with the Edison fuse is showTi in Fie-. 45. Within the last four or five years, a new form of fuse, known as the enclosed fu^e, has been introduced and used to a considerable Fig. 48. Porcelain Cut-Outs in Wooden Box extent. A fuse of this type is shown in Fig. 46. Fig. 47 gives a sec- tional view of this fuse, showing the porous filling surrounding the fuse-strips, and also the device for indicating when the fuse has blown. This form of fuse is made with various kinds of terminals; it can be used with spring clips in small sizes, and with a post screw contact in larger sizes. For ordinary low potentials this fuse is de- sirable for currents up to 25 amperes; but it is a debatable question 373 62 THE MOTION PICTURE TABLE VI Carrying Capacity of Wires Rubber Other IXSULATION ' Insulation B. & S. Gauge Circular Mils Amperes Amperes 18 1,624 3 5 16 2,583 6 8 14 4,107 12 16 12 6,530 17 23 10 10,380 24 32 8 16,510 33 46 6 26,250 46 65 5 33,100 54 77 4 41,740 65 92 3 52,630 76 110 2 66,370 90 131 1 83,690 107 156 105,500 127 185 00 133,100 150 220 000 167,800 177 262 0000 211,600 210 312 200,000 200 300 300,000 270 400 400,000 330 500 500,000 390 590 600,000 450 680 700,000 500 760 800,000 550 840 900,000 600 920 1,000,000 650 1,000 1,100,000 690 1,080 1,200,000 730 1,150 1,300,000 770 1,220 1,400,000 810 1,290 1,500,000 850 1,360 1,600,000 890 1,430 1,700,000 930 1,490 1,800,000 970 1,550 1,900,000 1,010 1,610 2,000,000 1,050 1,670 whether it is desirable to use an enclosed fuse for heavier currents. Fig. 48 shows a cut-out box with Edison phig fuse-blocks used with knob and tube wiring. It will be seen that there is no connection 274 ELECTRICAL PRINCIPLES 63 compartment in this fuse-box, as the circuits enter directly opposite the terminals with which they connect. Table VI shows the allowable carrying capacity of copper wires and cables of ninety-eight per cent conductivity, according to the standard adopted by the American Institute of Electrical Engineers and must be followed in placing interior conductors. For insulated aluminum wire the safe-carrying capacity is 84 per cent of that given for copper wire with the same kind of insulation. The lower limit is specified for mbber-covered wires to pre- vent gradual deterioration of the high insulations by the heat of the wires, but not from fear of igniting the insulation. The question of drop is not taken into consideration in the above tables. The carrying capacity of Xos. 16 and 18, B. & S. gauge wire is given, but no smaller than No. 14 is to be used, except as allowed under rules for fixture wiring. ARC LAMPS Electric Arc. Suppose two carbon rods are connected in an electric circuit, and the circuit closed by touching the tips of these rods together; on separating the car- bons again the circuit will not be broken, provided the space between the carbons be not too great but will be maintained through the arc formed at these points. This phenomenon, which is the basis of the arc light, was first obsen'ed on a large scale by Sir Humphrey Davy, who used a bat- tery of 2,000 cells and produced an arc between charcoal points 4 inches apart. As the incandescence of the car- bons across which an arc is maintained, together with the arc itself, forms the source of light for a large portion of arc lamps, it will be well to study the nature of the arc. Fig. 49 shows die general appearance of an arc between two carbon electrodes when maintained by direct current. Here the current is assumed as passing from the top carbon to Fig. 49. The Electric Arc Between Carbon Terminals 275 64 THE MOTION PICTURE the bottom one as indicated by the arrow and signs. We find, in the direct-current arc, that the most of the Hght issues from the tip of the positive carbon, or electrode, and this portion is known as the crater of the arc. This crater has a temperature of from 3,000° to 3,500° C, the temperature at which the carbon vaporizes, and gives fully 80 to 85 per cent of the light furnished by the arc. The negative carbon becomes pointed at the same time that the positive one is hollowed out to form the crater, and it is also incandescent but not to as great a degree as the positive carbon. Between the electrodes there is a band of violet light, the arc proper, and this is surrounded by a lu- o 100 V^-V" Ju— A— n"^ — 90* 200 80* 300 ■4O0 W BOO c — Y \ \/n\ / \/ / \\ / eoo — y'x 3c ^^ /\ / \/ / 60' 700 800 50* eoo lOOO -^foA^^x/ Fig. 50. Distribution Curve for D. C. Arc Lamp (Vertical Plane) minous zone of a golden yellow color. The arc proper does not fur- nish more than 5 per cent of the light emitted when pure carbon electrodes are used. The carbons are worn away or consumed by the passage of the current, the positive carbon being consumed about twice as rapidly as the negative. The light distribution curv^e of a direct-current arc, taken in a vertical plane, is shown in Fig. 50. Here it is seen that the maxi- mum amount of light is given off at an angle of about 50° from the vertical, the negative carbon shutting off the rays of light that are thrown directly downward from the crater. If alternating current is used, the upper carbon becomes positive and negative alternately, and there is no chance for a crater to be 276 f ELECTRICAL PRINCIPLES 65 foiTaed, both carbons giving off the same amount of light and being consumed at about the same rate. The light distribution curve of an alternating-current arc is shown in Fig. 5L Arc=Lamp Mechanisms. In a practical lamp we must have not only a pair of carbons for producing the arc, but also means for sup- Fig. 51. Distribution Curve for A. C. Arc Lamp (Vertical Plane) porting these carbons, together with suitable arrangements for leading the current to them and for maintaining them at the proper distance apart. The carbons are kept separated the proper distance by the operating mechanisms which must perform the following functions: 1. The carbons must be in contact, or be brought into contact, to start the arc when the current first flows. 2. They must be separated at the right distance to form a proper arc immediately afterward. 3. The carbons must be fed to the arc as they are consumed. 4. The circuit should be open or closed when the carbons are entirely consumed, depending on the method of power distribution. The feeding of the carbons may be done by hand, as is the case in some stereopticons using an arc, but for ordinary illumination the 277 66 THE MOTION PICTURE + -<0) A/wwwwwwv ^. ^ H Sn striking and maintaining of the arc must be automatic. It is made so in all cases by means of solenoids acting against the force of gra\aty or against springs. There is an endless number of such mechanisms, but a few only will be described here. They may be roughly di- vided into three classes: shunt mechanisms, series mechanisms, differential mechanisms. Shunt Mechanisms, In shunt lamps, the carbons are held apart before the current is turned on, and the circuit is closed through a solenoid connected in across the gap so formed. All of the current must pass through this coil at first, and the plunger of the solenoid is arranged to draw the carbons together, thus starting the arc. The pull of the solenoid and that of the springs are ad- justed to maintain the arc at its proper length. Such lamps have the disad- vantage of a high resistance at the start — 450 ohms or more — and are difficult to start on series circuits, due to the high voltage required. They tend to maintain a constant voltage at the arc, but do not aid the d}Tiamo in its regulation, so that the arcs are liable to be a little unsteady. Series Mechanisms. With the series-lamp mechanism the carbons are together when the lamp is first started and the current, flowing in the series coil, separates the electrodes, striking the arc. When the arc is too long, the resistance is increased and the current lowered, so that the pull of the solenoid is weakened and the carbons feed together. This type of lamp can be used only on constant-potential systems. Fig. 52 shows a diagram of the connection of such a lamp. This diagram is illustrative of the connection of one of the lamps manu- factured by the Western Electric Company, for use on a direct-current. t Fig. 52. Series Mechanism for D. C. Arc Lamp 278 ELECTRICAL PRINCIPLES 67 constant-potential system. The symbols + and — refer to the termi- nals of the lamp, and the lamp must be so connected that the current flows from the top carbon to the bottom one. jR is a series resistance, adjustable for different voltages by means of the shunt G. F and D are the controlling solenoids connected in series with the arc. B and C are the positive and negative carbons re- _ spectively, while A is the switch for turning the current on and off. H is the plunger of the solenoids and / the carbon clutch, this being what is known as a carbon-feed lamp. The carbons are together when A is first closed, the current is excessive, and the plunger is dra^\ni up into the solenoids, lift- ing the carbon B until the resistance of the arc lowers the current to such a value that the pull of the solenoids just counter-balances the weight of the plunger and carbon. G must be so adjusted that this point is reached Fig. 53. Differential Mechan- , ,1 • J 'j 11 ji ism for D. C. Arc Lamp when the arc is at its normal length. Diferential Mechanisms. In the differential lamp, the series and shunt mechanisms are combined, the carbons being together at the start, and the series coil arranged so as to separate them wliile the shunt coil is connected across the arc, as before, to prevent the car- bons from being drawn too far apart. This lamp operates only over a low-current range, but it tends to aid the generator in its regulation. Fig 53 shows a lamp having a differential control, this also being the diagram of a Western Electric Company arc lamp for a direct- current, constant-potential system. Here S represents the shunt coil and ^1/ the series coil, the armature of the two magnets A and A' being attached to a bell-crank, pivoted at B, and attached to the carbon clutch C. The pull of coil S tends to lower the carbon while that of M raises the carbon, and the two are so adjusted that equilibrium is reached when the arc is of proper length. All of the lamps are fitted with an air dashpot, or some damping device, to prevent too rapid movements of the working parts. The methods of supporting the carbons and feeding them to the arc may be divided into two classes: rod-feed mechanism, carbon-feed mechanism. 279 68 THE MOTION PICTURE Rod-Feed Mechanism, Lamps using a rod-feed have the upper carbons supported by a conducting rod, and the regulating mechan- ism acts on this rod, the current being fed to the rod by mean^ of sHding contact. Fig. 54 shows the arrangement of this type of feed. The rod is shown at /?, the shding contact at B, and the carbon is attached to the rod at C. These lamps have the ad- vantage that carbons, which do not have a uniform cross-section or smooth exterior, may be used, but they possess the disadvantage of being very long in order to ac- commodate the rod. The rod must also be kept clean so as to make a good contact with the brush. Carbon-Feed Mechanism. In carbon-feed lamps the controlling mechanism acts on the carbons directly through some form of clutch which grips the carbon when it is lifted, but allows the car- bon to slip through it when the tension is released. For this t^^x of feed the carbon must he straight and have a uniform cross- section as well as a smooth exterior. The current may be led to the carbon by means of a flexible lead and a short carbon holder. MOVINQ=PICTURE MACHINES Arc Lamp. Arc lamp used as a part of moving picture machines must be constructed similar to arc lamps of theaters, and wiring of same must not be of less capacity than No. 6 B. & S. gauge. Arc lamps used for stage effects must conform to the following requirements: a. Must be constructed entirely of metal except where the use of approved insulating material is necessary. b. Must be substantially constructed, and so designed as to Fig. 54. Rod-Feed Mechanism 280 ELECTRICAL PRINCIPLES 69 provide for proper ventilation, and to prevent sparks being emitted from lamps when same is in operation, and mica must be used for frame insulation. c. Front opening must be provided with a self-closing hinged door frame in which wire gauze or glass must be inserted, excepting lens lamps, where the front may be stationary, and a solid door be provided on back or side. d. Must be provided with a one-sixteenth-inch iron or steel guard having a mesh not larger than 1 inch, and be substantially placed over top and upper half of sides and back of lamp frame; this guard to be substantially riveted to frame of lamp, and to be placed at a distance of at least 2 inches from the lamp frame. e. Switch on standard must be so constructed that accidental contact with any live portion of same will be impossible. /. All stranded connections in lamp and at switch and rheo- stat must be provided with approved lugs. g. Rheostat, if mounted on standard, must be raised to a height of at least 3 inches above floor line, and in addition to being properly enclosed must be surrounded with a substantially attached metal guard having a mesh not larger than 1 square inch, which guard is to be kept at least 1 inch from outside frame of rheostat. h. A competent operator must be in charge of each arc lamp, except that one operator may have charge of two lamps when they are not more than 10 feet apart, and are so located that he can prop- erly watch and care for both lamps. Miscellaneous. Rheostats must conform to rheostat require- ments for theater arcs. To'p reel must be encased in a steel box with a hole at the bottom only large enough for film to pass through, and cover so arranged that this hole can be instantly closed. No solder to be used in the con- struction of this box. A steel box must be used, for receiving the film after being shown, with a hole in the top only large enough for the film to pass through freely, with a cover so arranged that this hole can be instantly closed. An opening may be placed at the side of the box to take the film out, with a door hung at the top, so arranged that it cannot be en- tirely opened, and provided with spring catch to lock it closed. No solder to be used in the construction of this box. 281 70 THE MOTION PICTURE The handle or crank vised in operating the machine must be secured to the spindle or shaft, so that there will be no hability of its coming off and allowing the film to stop in front of lamp. A shutter must be placed in front of the condenser, arranged so as to be readily closed. Extra films must be kept in metal box with tight-fitting cover. Machines must be operated by hand (motor driven will not be permitted). Picture machine must be placed in an enclosure or house made of suitable fireproof material, be thoroughly ventilated and large enough for operator to walk freely on either side of or back of ma- chine. All openings into this booth must be arranged so as to be entirely closed by doors or shutters constructed of the same or equally good fire-resisting material as the booth itself. Doors or covers must be arranged so as to be held normally closed by spring hinges or equivalent devices. *MERCURY=ARC RECTIFIERS FOR MOTION PICTURES One of the most important factors contributing to the success of a motion-picture theater is the quality and brilliancy of the light projected from the lamps. For pleasing effect motion pictures re- quire a steady, white light of sufficient intensity to bring out the natural light and color values of the films, and the theater having the best quality of light stands the best show of getting the biggest patronage. It is well known that the light obtained from the direct- current is much superior to that from the alternating-current arc lamps. However, until recently all those who could obtain only alternating-current supply have got along with the poorer quality of light simply for the lack of apparatus for economically converting alternating current into direct current. In Fig. 55 is shown a mercury-arc rectifier developed by the General Electric Company for furnishing current of the desired char- acter at a cost less than that of the most economically operated alternating-current arc lamp. There are certain facts which should be borne in mind while making an analysis of the cost of producing a given intensity of pro- jected light from alternating current, direct current, and rectified *By courtesy of the McGraw Publishing Company. 282 I » ELECTRICAL PRINCIPLES 71 current with the most approved devices applicable in each case. For instance, the best class of motion pictures requires a light in- tensity of upward of 8,000 candle power, and as 5,000 candle power is the maximum obtainable from alternating current with the best auto-transformers, or the highest current values practicable, it is evident (hat the use of alternating current under such conditions is Fig. 55. Front and Back Views of Mercury-Arc Rectifier for Moving-Picture Machine entirely satisfactory- owing to the insufficiency of the light. Where direct-current supply is obtainable, some have found relief by using it, but their experience has served to emphasize the prohibitory effect of the additional cost entailed by the loss of at least 60 per cent of the energy drawn from the line in the resistance or rheostat employed to regulate the current in the arc. These facts serve to define the limitations of both the alternating- 283 72 THE MOTION PICTURE current and the direct-current arc relative to motion-picture light- ing, but in order to give the various alternating-current methods a fair basis for comparison, assume that a light intensity of 5,000 candle power is required. From actual determinations carefully made it is found that to obtain 5,000 candle power from a 110- volt alternating-current circuit with rheostats requires 7 kilowatts; a 110- volt direct-current circuit with rheostat requires 2.25 kilowatts; an}^ alternating-current circuit with auto-transformer requires 2.1 kilowatts, and with mercury-arc rectifier requires 1.7 kilowatts. Since auto-transformers are extensively used in alternating- current supply systems to obtain a substantial reduction in energy consumption, the method of using alternating current with rheostats may be considered as obsolete, and since a prohibitory amount of energy is wasted in using direct current with a rheostat, that method can be omitted from present consideration. This affords a direct comparison between the alternating current with the use of econo- mizers on the one hand and mercury-arc rectifiers on the other. The figures given above show a difference of 400 watts in favor of the mercury-arc rectifier. This means than on the basis of an average daily run of seven hours at a cost of 6 cents a kilowatt-hour the use of a mercury-arc rectifier provides a light having all the advantages of that given by a direct-current arc at a cost of at least $60 per year less than that obtained from alternating current with the best type of auto-transformer. Furthermore, it is evident that when the light intensity required exceeds 5,000 candle power, thus rendering the alternating-current method inapplicable, the saving effected by the use of the mercury- arc rectifier as compared to the cost of using direct current with a rheostat is much more significant. For instance, to obtain 7,500 candle power requires 3.1 kilowatts from direct current with rheostat and 2.15 kilowatts from alternating current with mercury-arc rec- tifier. The difference in favor of the mercury-arc rectifier is 950 watts, which means a saving of at least $145 per year. In addition to the positive money-saving capability of the device, the excellent light of practically any candle-power obtainable from alternating-current supply and the reliability, ease, and safety of operation render the mercury-arc rectifier particularly desirable for making pleasing and successful "photo plays." 284 INDEX The page num^'ers of this volume will be found at the bottom of the pages; the numbers at the top refer only to the section. ] Part Page Part Page A Arc lamps II, 275 Aberration n, 20 electric arc II, 275 Acetylene I, 16 mechanisms II, 277 Actors II, 105 Astigmatism II, 22 starring an actor II, 106 Atlas Film Company I, 278 stock companies II, 105 Author II, 76 Adjustable lens I, 94 his problems II, 77 Advertising II, 197 art, limitations of II, 77 Advertising drop curtain II, 207 plot II, 77 Advertising slides II, 207 scenario II, 78 Airdome II, 195 who is II, 95 Ajax Film Company I, 277 Autochrome plates II, 65 Alignment masks I, 42 Automatic music II, 203 Alternating-current arc I, 19 Automatic shutter I, 159 Ambrosio Film Manufacturing Auxiliary rheostat I, 47 Company I, 277 Auxiliary rheostat for double American Cinephone Company I, 277 lantern I, 48 American Film Manufactur- Auxiliary switch I, 49 ing Company I, 277 American Kinograph Company I, 277 B American Motor Racing Pic- ture Company I, 278 Barker Motion Photography 278 American Mutoscope and Bio- Barrel shutter 97 graph Company I, 278 Bat films 278 Animated Motion-Picture Pat- Bavaria Film Manufacturing ents Company I, 278 Company 278 Animatophone Syndicate I, 278 Beater movement 113 Announcement slides I, 72 ; II 199 Pitman type 114 Aquila Film Manufacturing spring-bar type 114 Company I, 278 wrist-pin type 114 Arc Before-t he-lens shutter 98 alternating-current I, 19 Bianchi camera ii! 140 direct-current I, 17 Bichromatic cell II, 226 electric I, 17 "Biograph" film 278 Arc-lamp mechanism II, 277 "Bison" 11, 278 differential mechanism 11, 279 Blue prints II, 55 rod-feed mechanism II, 280 Bushings II, 271 series mechanism II, 278 W. Butcher & Sons 11, 278 Note. — For page numbers see foot of pages. 285 INDEX Part Page Part Page c Chromatic aberration II, Calcium or gaso-oxygen light ] [, 152 Chronophotography II, 69, Camera II, 11, 122 motographic microscopy 11, buying 11 [, 13 motographic ultramicros- construction of I] 14 copy II, exposed and unexposed X-ray motography II, films [, 126 Cinephone I, film movement [, 12.3 Cinephone, operation of I, loading , 127 Claw movement I, loading film holders [, 125 Clement, E. G. I, talking-picture [, 257 Color, production of I, Camera man [, 122 Colored photographs il, Camera man's duties [, 128 Coloring films 11, control of image [, 133 hand process II, duplicate exposures [, 138 machine process 11, exposure control L, 134 stencil process 11, exposure meters [, 136 Colormotography I, exposure time [, 134 Friese-Green process I, finders L, 139 color shutter I, focusing [, 132 development of system I, indicator [, 139 manufacture I, lens length [, 131 projection of film I, marker [, 139 splices I, reversing [, 139 Urban-Smith process I, setting up camera [, 131 alternate projection I, shutter [, 133 Kinemacolor machine I, taking picture [, 128 making Kinemacolor trick crank [, 138 film pictures I, turning crank [, 129 production of color I, Camera operation, routine of I [, 27 Columbia Film Company I, Cameragraph, Powers' No. 5 1 , 189 Comedy II, Cameragraph, Powers' No. 6 1 [, 200 specimen II, Candy kid 11 [, 208 Competition II, Capitol Film Company [, 278 Condensers I, ^ Carbons, angle of [, 21 adjustment of optical sys- Carbons, cored [, 20 tem I, Carlton Motion-Picture Lab- adjustment for slides or oratories , 278 motion head I, Carrier, simple form of ] [, 33 development I, Carriers for Americar I and diffusion projection I, foreign slides [, 34 emergency projection I, Cells, combination of I] [, 230 focal lengths I, Champion Film Company [, 278 part of lens I, Chase and trick scrip, speci- plano-convex condensers men I] [, 83 in pairs I, Chases I] [, 72 Conductivity II, "Chicken Film" ] [, 278 Cone shutter I, Note. — For page numbers see foot of pages. 286 INDEX Pari Page Pari . Page Continental Film Manufactur- Dial-regulated machine I 251 ing Company I 278 cinephone I 254 Continuous projection I 118 Greenbaum I 251 duplex projection I 118 Diffusion projection I 31 moving lenses I 119 Direct-current arc I 17 moving mirrors I 120 Disk shutter I 97 moving prisms I 121 Dissolving lanterns I 37 steady feed elements I 121 alignment masks I 42 Cored carbons I 20 dissolving shutters I 42 Cosmopolitan Film Company I 278 double I 39 Country theater II 192 equipment of second lan- Cricks & Martin I 278 tern I 43 Croce, Adolpho I 277 operation of double-lantern I 43 Current events II 72 precautions in dissolving I 44 Current flows, laws of II 236 reversals I 44 Curvature, remedy for I 65 single-lantern dissolvers I 43 Curvature of image I 64 speed of change I 46 D triple I 37 Dissolving shutters I 42 Daniell cell II 227 Double lantern I 39 Darkroom II 27 Double lantern, operation of I 43 Defender films I 278 Double pin movement I 104 Dependent machines I 249 Double star movement I 104 Developing formulas II 48 Drama scrip, specimen II 78 acid hypo fixing bath II 49 Dramas II 72 hydro-metal developer II 48 Drankoff Ste. I 278 intensification II 50 Drawn pictures II 73 pinholes II 51 Drunken-screw movement I 105 plain hypo fixing bath II 48 Dry cell II 229 pyro developer II 48 Dry film I 133 reduction II 50 Dry plates II 35 removing pyro stains II 49 Dull season II 205 retouching and spotting II 50 Duplex projection I 118 Developing papers II 56 E Developing prints II 148 Development II 43 Eccentric sprocket movement I 108 developers II 43 Eclair films I 278 factorial II 46 Edengraph projector I 229 fixing II 47 Edison film mender I 155 fixing after washing II 47 Edison kinetoscope I 143 negative image II , 43 automatic shutter I 159 ruby lamp II 44 calcium or gaso-oxygen sight II 44 light I 152 tank II 46 film mender I 155 trays and covers II 44 film winder I 154 washing before fixing II , 47 gaso-oxygen saturator and without red lamp II 47 burner I 158 Note. — For page numbers see fool of pagse 287 4 INDEX Part Page Part Page Edison kinetoscope Electromagnetism installation 143 rules for north and south arc lamp 147 poles of a helix 11, 233 assembling 143 Electromotive force of galvanic cone and bracket 147 cells 11, 220 index of parts I, 144 -146 Electromotive force and its lamp house 146 measurements II, 218 operating gaso-oxygen li ght I, 155 Emergency projection I, 30 operation 147 Emergency slides I, 72 carbons 147 Equipment of second lan- connecting cords 148 terns I, 43 focusing 148 Essanay Film Manufactur- stereopticon lens 148 ing Company I, 279 rheostats 160 Exposure II, 35 rules 151 calculation of II, 40 take-up device 148 duplicate II, 42 threading up film 152 exposure meters II, 41 adjustable rheostat 153 light intensity 11, 38 framing device 153 nature of subject II, 38 general instructions 153 plate speed II, 37 wiring 149 stop numbers II, 36 Edison Manufacturing Com- with single lens II, 42 pany I, 279 F Electric arc I, 17; II 275 Electric bell II, 235 Feature films II, 200 Electric signs 11, 198 Feeders and mains II, 263 Electrical currents, measure- Feed reel I, 122 ment of 11, 218 Feed-reel magazine I, 122 Electric principles II, 213 -284 Film I, 129 arc lamps n, 275 care in handling I, 130 electricity in motion 11, 213 care in projecting I, 129 electromagnetism n, 232 care in rewinding I, 130 laws of current flow II, 236 care in storage I, 130 mercury-arc rectifiers II, 282 dry I, 133 moving-picture machines II, 280 leaders and tails I, 133 primary cells II, 223 packing for shipment I, 130 wiring methods II, 256 repair of I, 130 Electrical resistance II, 221 splicing I, 131 Electricity in motion II, 213 threading up I, 152 Electromagnet II, 234 titles I, 133 Electromagnetism II, 232 warped I, 134 electric bell II, 235 Film, perforation of II, 119 electromagnet 11, 234" perforating machines II, 121 magnetic properties of a perforating room II, 122 helix II, 233 shape II, 120 magnetic properties of a spacing II, 119 loop II, 232 Film, storage of 11, 119 Note. — For page numbers see foot of pages. 288 INDEX Part Page Part Page Film basket or molasses can 1 , 127 Fire shutter I, 100 Film D'Art Film Manufac- Focal lengths I, 29 turing Company ] , 279 Focusing I, 62 Film development 11 , 141 curvature, remedy for I, 65 cages I] , 141 inclined optical axis I, 65 developing I] , 142 inclined screen I, 70 drying II , 142 keystone mask I, 71 room II , 142 keystone picture I, 67 trays II , 141 lens angle I, 69 washing II , 142 Framing devices I, 125 Film gate I, 100, 123 Fuse-boxes, cut-out panels, etc. 11, 272 adjustment of tension G springs I . 101 care I , 101 Galvanic cell II, 214 construction I , 101 electromotive forces of II, 220 functions I , 100 internal resistance of II, 222 Film industry, branches of II , 112 Galvanic cell and static ma- Film manufacturers I, 2' r7-282 chine, comparison of II, 216 Film mender, Edison I , 155 Gaso-oxygen light, operating I, 155 Film shift or intermittent Gaso-oxygen saturator and movement I , 102 burner I, 158 adjustment of I , 116 Gaumont Company I, 279 beater I , 113 Geneva or pin-and-star move- claw I , 112 ment I, 102 double pin I , 104 Gnome Motion Picture Com- double star I , 104 pany I, 279 drunken-screw I , 105 Great Northern Film Com- eccentric sprocket I , 108 pany I, 279 intermittent grip mechan- Guard I, 25 ism I , 115 H intermittent sprocket I , 102 modified drunken-sere- I , 107 Hamacek camera II, 140 pin I , 109 Handbills II, 200 , 208 pin-and-star I , 102 Hepworth Manufacturing Com- pitman I , 104 pany I, 279 ratchet I , 105 Hispano films I, 279 single-sprocket I , 107 Hiring employes II, 202 snail I , 106 Horsley, David I, 279 spring latch I , 106 I Film splicing I , 131 framing by splicing I , 132 Image by machines I , 132 curvature of I, 64 "in frame" ] , 132 inverted II, 12 non-inflammable I , 132 pin-hole 11, 11 Film steady drum ] , 123 recording II, 35 Film winder 1 , 154 "Imp" I, 279 Financing a picture theater II , 175 Inclined optical axis I, 65 Note. — For page numbers see foot of pages. 289 6 INDEX Part Page Part Page Inclined screen I, 70 Lamp Income vs. expense n, 172 adjustments ] , 20 Independent Moving Picture alternating-current arc 1 , 19 Company of America I, 279 angle of carbons 1 , 21 Industrial scrip, specimen n, 94 centering light 1 , 22 Industrials II, 71 cored carbons ] , 20 Intermittent grip mechanism I, 115 direct-current arc ] , 17 Intermittent sprocket I, 102 123 electric arc ] , 17 Inverted image II, 12 focusing light ] , 23 Inverted slide I, 13 stereo vs. motion arc ] , 19 Italia Film Manufacturing Lamp adjustments ] , 20 Company I, 279 Lamphouse ] , 24 K guard '. , 25 pinhole image peephole '. , 24 Kalem Film INIanufacturing sliding house [, 24 Company 279 ventilation , 25 Keeping accounts u, 203 Lantern, elements of [, 11 Keystone mask 71 inverted slide [, 13 Keystone picture 67 optical system [, 12 remedy for 68 placing slide in holder [, 14 Kinemacolor Company of thumb spots [, 14 America 279 Lantern slides I, 72 II, 6] Kinemacolor film pictures, announcement [, 72 making of 263 emergency [, 72 Kinemacolor machine 267 repair of I, 73 adjustment of color screen 268 "Latium" Film I, 279 arc lamp 272 Leaders and tails I, 133 direction of film wind 273 Leclanche cell I I, 229 film inspection 271 "Le Lion" Cinematographes framing 270 Company I, 279 intermittent mechanism 267 Lens I, 51 oiling 272 accurate calculations I, 60 splicing 270 adjustable I, 94 Kinephotography n! 70 calculating lens data with- chases II, 72 out table I, 57 comedies n, 72 for length of throw I, 59 current events II, 72 for lens length I, 58 dramas II, 72 for picture size I, 58 industrials II, 71 for slide size I, 58 travels II, 71 care of I, 61 trick pictures II, 72 construction and adjust- "Kineto" films 279 ments I, 61 Kinetoscope, Edison 143 corrections I, 51 Kleine, George 279 estimating lens length I, 57 L lens focus, length of I, 54 Lamp 15 for given requirements I, 53 acetylene 16 to take length of throw I, 91 Note. — For page numbers see foot of pages 290 INDEX Part Page Lens to take lens length 90 to take picture size 91 Lens angle 69 Lens printing 58 enlargements 59 Lenses 14 astigmatism 22 chromatic aberration 20 diaphragm opening 17 focal length 16 focusing 19 measuring length 17 spherical aberration 20 Light centering of 22 focusing of 23 Lime light 16 Lining up double lantern 41 "Lion's Head" Film 280 Location of picture theater II! 173 among competitors n, 173 new territory n, 174 small town n, 175 Lubin Manufacturing Com- pany 280 Lubin projector 235 Lux Film Manufacturing Com- pany I, 280 M Magnetic effect due to a charge in motion II, 213 Magnetic field about a current, shape of Making titles Manager, art of Manifattura Cinematografica Italia Mechanical slide changers Melies, G. Mercury-arc rectifiers for mo- tion pictures Metal-surfaced screen Mirror screen II, 187 Modified drunken-screw move- ment I, 107 Note. — For page numbers see foot of pages. II, 217 n, 143 n, 169 I, 280 I, 36 I, 280 n, 282 n. 186 Part Page Monochroming II, 149 Motiograph I, 161 how to install or set up I, 161 index of parts I, 179-188 instructions I, 170 adjustments I, 170 oiling I, 172 lens adjustment I, 166 setting shutters I, 174 threading the film I, 167 Motiograph shutters, setting I, 174 Motion, portrayal of I, 75 motion mechanism I, 83 perfected motion picture I, 77 persistence of vision I, 81 projection by persistence of vision I, 82 proof of I, 76 viewing devices I, 80 Motion head colormotography continuous projection film film gate film manufacturers film shift or intermittent movement I, operator's duties I, optical system for motion pictures I, portrayal of motion I, shutter I, specific projecting machines I, talking pictures I, threading up motion head I, Motion-head lantern I, auxiliary rheostat I, auxiliary switch I, Motion head, threading up I, automatic rewind I, feed reel I, film-basket I, film gate I, film steady drum I, framing devices I, intermittent sprocket I, lower feed loop I, I, 75-282 I, I, I, I, I, 262 118 129 100 277 102 134 84 75 95 141 241 122 47 47 49 122 126 122 127 123 123 125 123 124 291 . 8 INDEX Part Page Motion head, threading up lower steady-feed sprocket I, 124 motor vs. crank I, 128 operator's control of picture I, 128 rewinding !> 126 take-up reel I, 124 upper feed loop I, 123 upper steady feed I, 122 Motion mechanism I, 83 Motion Picture Distributing and Sales Company I, 280 Motion Picture Patents Com- pany of America I, 280 Motion picture, perfected I, 77 Motion-picture theater II, 165-210 management II, 165 art of manager II, 169 competition H, 171 income vs. expense II, 172 "sick" motion-picture theater II, 165 theater for profit II, 172 traffic II, 172 operation II, 195 advertising II, 197 announcement sUdes II, 199 automatic music II, 203 dull season II, 205 electric signs II, 198 feature films II, 200 handbills II, 200 hiring employes II, 202 keeping accounts II, 203 newspapers II, 200 noise wagon II, 200 poster service II, 198 printed programs II, 200 program II, 196 renting films II, 202 side lines for profit II, 207 song slides II, 202 special program II, 201 studying audiences II, 195 tickets and chopper II, 205 vaudeville II, 203 starting a theater II, 173 financing II, 175 Note— For page numbers see foot of pages. Motion-picture theater selecting location among competitors new territory small town special buildings airdome country theater Part Page II, 173 II, 173 II, 174 II, 175 II, 188 II, 195 II, 192 exclusive picture house I, 189 small vaudeville theater II, 189 store - front city theater building II, 176 Motographic microscopy II, 156 Motographic ultramicroscopy II, 156 Motography II,. 69-162 author II, "7 methods of production II, 73 division of labor II, 76 early II, 73 drawn pictures II, 73 photographic process II, 74 separate cameras II, 74 multiple camera II, 74 modern II, 75 producer II, 95 product desired II, 69 reproduction II, 116 salesman II, 112 Moving-picture machine II, 280 arc lamp II, 280 extra films II, 282 handle II, 282 machines II, 282 rheostats II, 281 shutter II, 282 steel box II, 281 top reel II, 281 Multiple disk shutter I, 99 N Navone Film I, 281 "Nestor" Films I, 281 Newspaper advertising II, 200 New York Motion Picture Company I, 281 Noise wagon II, 200 292 INDEX O Ohm's law applications of divided circuits fall of potential in cir- cuit joint resistance of di- vided circuits series circuits simple applications Operation of double lantern Operation of a picture theater Operator's control of picture Operator's duties before show begins conducting program keeping up with times preparing for projection Optical lantern condensers dissolving lanterns elements of lantern focusing lamp lamphouse lantern slides lens motion-head lantern slide carrier Optical system adjustment of Optical system for motion pic- tures accurate calculations adjustable lenses approximate calculations condensers as a pair back front short rules for lengths lamp lenses matched lenses (stereo and motion head) Orthochromatic photography Outlet boxes Outlets, location of Note. — For page numbers sec fool of pages. Part Page P Part Page n, 222 Packing films for shipments II, 154 II, 248 Panoramas II, 62 II, 252 Paragon Bioscope Company I, 281 Pathe Freres I 281 II, 250 Pathe professional model pro- jector I 206 II 254 Photographer II 116 II, 249 Photographic equipment II 155 II, 248 buying cameras II 155 43 buj'ing films II 155 II 195 fire risk in storing films II 155 128 making cameras II 155 134 Photographic factory, division 134 of II 116 135 Photographs, colored II 64 137 Photography II, 11-66 135 mechanical details II 11 I,' 11-73 orthochromatic II 64 25 printing II 51 37 recording image II 35 11 special application of II 61 62 theory II 11 15 tri-color II 65 24 Piccadilly Circus I 281 72 Picture house, large exclusive II 189 51 Pictures without studios II 103 47 Pin movement I 109 33 Pin-cross movement I 108 12 Pin-hole image II 11 31 Pin-hole image peephole I 24 Pitman movement I 104 84 Plano-convex condensers in 92 pairs I, 28 94 Plate-holder II 26 92 Polarization II, 226 84 bichromatic cell II 226 87 Daniell cell II 227 84 dry cell II 229 86 Leclanche cell II 229 88 Polyscope, Selig I 225 84 Portrayal of motion I 75 88 Poster service II, 198 Powers Company I, 281 93 Powers' No. 5 cameragraph I, 189 II! 64 Powers' No. 6 cameragraph I, 200 II, 269 Primary cells II, 223 II, 258 action of a simple cell II, 223 293 10 INDEX Part Page I 'art Page Primary cells Producing a drama combination of cells II, 230 rewriting n, 110 polarization n, 226 titles II, 110 storage battery II, 231 Producing image II, 28 Print spotting II, 149 background II, 29 Printed program n, 200 composition and balance II, 31 Printing 11,51 144 distortions II, 34 developing papers n, 56 horizon line II, 32 developing prints 11, 148 lighting II, 30 exposure n, 146 point of view II, 32 film adjustment durin g principal object II, 29 printing n. 147 prominence of background II, 32 hand staining 11, 150 rising front 11, 35 inspection 11, 148 size of object II, 30 lens printing II, 58 swing back II, 34 machines II, 144 Program II, 196 making exposure ticket II, 148 Program advertising II, 208 print spotting II, 149 Projection I, 118 printing frame II, 52 Projection with Edison lenses I, 161 printing-out papers II, 52 Projectors processes II, 51 Edengraph I, 229 repeater printing II, 150 Lubin I, 235 room II, 144 Pathe professional model I, 206 self-toning paper II, 55 Properties and costumes II, 105 staining II, 149 R toning or monochroming II, 149 Printing-out papers II, 52 Ratchet movement I, 105 chloride papers II, 52 Raw film II, 117 combined toning and fixing II, 55 coating II, 118 final washing 54 composition II, 117 fixing 54 manufacture II, 117 stopping 54 non-inflammable II, 118 toning 53 Recording image II, 35 washing before toning 53 development II, 43 Producer of picture 95 dry plates II, 35 actors 105 exposure II, 35 pictures without studios 103 films II, 35 producing a drama 107 Rehearsals II, 106 properties and costumes 105 "Reliance" I, 281 rehearsals 106 Renting films II, 202 studio lighting 101 Repair of slides I, 73 studio scenes 96 Reproduction II, 116 Producing a drama 107 camera II, 122 final criticism 111 camera man II, 122 motion scenes 108 camera man's duties II, 128 padding 109 chromophotography II, 155 review and criticism 109 coloring films 11, 151 Note. — For page numbers see fool of pages. 294 INDEX 11 Part Page Part Page Reproduction Shutters I, 95; 11,24 development of films 11, 141, automatic j , 159 factory floor plan 11, 140 cap I] , 24 making titles n, 143 curtain I] , 24 packing films for shipment 11, 154 fire ] , 100 perforation of films n, 119 focal plane i; , 25 photographer II, 116 leaf 11 , 24 photographic equipment II, 155 setting ] , 100 photographic factory- II, 116 testing I] , 25 printing II, 144 types of ] , 97 raw film II, 117 barrel ] , 97 reclaiming waste II, 154 before-the-Iens ] , 98 storage of film II, 119 cone - ] , 99 trick pictures II, 156 disk ; , 97 waterproofing II, 154 multiple-disk ] , 99 Resistance II, 236 Sicania Film Factory , 281 affected by heating II, 242 "Sick" motion-picture theater I. , 165 calculation of II, 239 Side lines for profit L , 207 inversely proportional to advertising drop curtain L , 207 cross-section II, 237 advertising slides 1. , 207 proportional to length 11, 236 candy kid I] , 208 specific resistance II, 238 handbills 11 , 208 Reversals I, 44 program advertising I] , 208 Revier Motion Picture Com- refreshment annex I] , 210 pany I, 281 sheet music sales I] , 210 Rewinding of film I, 126 wall posters 11 , 207 Rheostats I, 160 Sight development I] , 44 Ruby lamp II, 44 Sign flasher I] , 199 S Simple cell, theory of action of I] , 224 Single-lantern dissolvers ] , 43 Salesman II, 112 Single-sprocket movement ] , 107 advance shipment II, 114 sHde ahgnment ] , 45 branches of film industry II, 112 Slide carrier ] , 33 factory schedule II, 114 American and foreign ] , 34 lectures II, 112 simple form of ] , 33 release dates II, 113 slide-window masks ] , 34 sales contracts n, 115 slide-window shutters ] , 35 selling methods II, 112 slip slide ] , 35 title posters II, 116 Slide, inverted ] 13 Scenario II, 78 Slide-window masks ] , 34 Second lantern, equipment of I, 43 Slide-window shutters 1 , 35 Self-toning paper II, 55 Slides blue prints II, 55 inverted ] , 13 sepia II, 56 storage of 1 , 37 Selig polyscope I, 225 Sliding house 1 , 24 Selig Polyscope Company I, 281 Slip slide carrier 1 , 35 Sheet music sales II, 210 Slot machines I] , 209 Note. — For page numbers see foot of pages. 295 12 INDEX Part Page Small vaude\nlle theater 11, 189 Snail movement I, 106 Societe Cines I, 281 Solax Company I, 281 Song slides n, 202 Special biiildings II, 188 airdome II, 195 countrj- theater II, 192 large exclusive picture house II, 189 small vaudeville theater II, 189 Special programs II, 201 amateur night n, 201 contests 11, 201 double price II, 202 school children II, 201 Specific projecting machines I, 141 Edengraph projector I, 229 Edison kinetoscope I, 143 Lubin projector I, 235 Motiograph I, 161 Pathe professional model projector I, 215 Powers' No. 5 cameragraph I, 189 Powers' No. 6 cameragraph I, 200 Selig polyscope I, 225 Standard projector I, 220 Specific resistance II, 238 Speed of change I, 46 Spherical aberration II, 20 Spring latch movement I, 106 Staining II, 149 Standard projector I, 216 index of parts I, 220 rewinding of I, 223 Stereo vs. motion arc I, 19 Stereographs II, 62 Stop picture II, 161 Storage battery II, 231 Storage of slides I, 37 Store-front city theater build- ing II, 176 elaborate store front II, 181 floor plan II, 177 lighting methods II, 179 low-cost store front II, 179 picture screen n, 186 sloping floor II, 184 Part Page Store-front city theater build- ing specimen expense sheet II, 184 stage II, 185 weekly expense sheet II, 183 Studio Hghting II, 101 artificial II, 101 daylight II, 102 glass house tj^pe II, 102 turntable type II, 103 yard studio type II, 103 Studio scenes II, 96 Sunny South Film Company I, 281 Synchronous electric motor I, 246 Tables American wire gauge (B. & S.) day and hour exposure chart equivalent stop numbers in focal-factor and uni- form systems exposure chart lens data primary' cells, electromo- tive force, resist- tance, etc. II, relative resistance of chem- icall}^ pure sub- stances at 32 F. in- ternational ohms screen image, size of when moving picture films are projected Stubs' or Birmingham Wire Gauge (B.W.G.) temperature coefficients wires, carrying capacity of Take-up reel Talking-picture camera Talking pictures dependent machines dial-regulated machine length of records manufacture II, 244 II, 39 II, 37 II, 135 I, 55 246-247 II, 240 I, 89 II, 245 II, 243 II, 274 124 257 241 249 251 244 255 Note. — For page numbers see foot of pages. 296 INDEX 13 Part Page Part Page Talking pictures Urban, Chas., Trading Com- recording sound I, 242 pany I, 282 reproduction of I, 258 V synchronism . I, 242 unitary machines I, 245 Vaudeville II, 203 Telephotography n, 63 Ventilation I, 25 Tension springs, adjustment of I, 101 Viewing devices I, 80 Thanhouser Company I, 281 Vision Theater, starting n, 173 persistence of I, 81 Threading up motion head I, 122 projection by persistence of I, 82 Thumb spots I, 14 Vitagraph Company of America I, 282 Tickets and chopper n, 205 Title posters II, 116 W Titles I, 133 Wall posters II, 207 Titles, framing of I, 270 Warped film I, 134 Toning n, 149 Warwick Trading Company I, 282 Traffic 11, 172 Waterproofing II, 154 Travel and comedy scrip, speci- Wiring methods II, 256 men 11, 92 outlet boxes, cut-out pan- Travel scrip, specimen II, 90 els, etc. II, 269 Travels II, 71 planning an installation II, 256 Trick notes II, 87 Wiring an office building II, 264 Trick pictures II, 72 , 156 basement II, 265 blackroom II, 160 character of load II, 265 dissolving views n. 159 electric current supply II, 264 double exposures II, 159 feeders and mains II, 265 double printing II, 159 first floor II, 268 dummies II, 157 interconnection system II, 268 ghosts II, 158 second floor 11, 268 mirrors II, 160 switchboard II, 264 reversals II, 157 upper floors II, 268 speed pictures II, 157 "Wrench" Films I, 282 stop picture II, 161 X Tri-color photography II, 65 Triple lantern I, 37 X-Ray motography II, 156 Tyler Film Company I, 282 Y U Yankee Film Company I, 282 Unitary machines I, 245 Z Unitas Film Manufacturing Company I, 282 Zoetrope 11, 73 Nole. — For page numbers see foot of pages. 297 37 W^ Or i^^ % w^ % w^ % ^ \ s "d, i ^^ \ i i o .4^ UNIVERSITY OF CALIFORNIA LIBRARY Los Angeles This book is DUE on the last date stamped below. 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