Motion Picture News (Sept-Oct 1918)

2424 (Equipment Service) Motion Picture News (Continued from page 2422) the images at that point. This frequently occurs, following a bad splice in the negative, but the films generally come into correct register again within a few feet of film, or within the space of a few images if the machine be a good one and in proper adjustment. However, the defect brought to our attention by Mr. Rosecrans is directly chargeable to the laboratory, and one which should not be allowed to persist, for although slight defects frequently occur in the making of positive prints, these are all supposed to be removed before the films are shipped out by the laboratory. When misframes and places out of register are discovered in a new print, with no splices existing in the vicinity of the defective spots, it is readily apparent that such defects are of laboratory origin, and it is also fair to assume, in such instances, that the prints have not been inspected by the laboratory at all. We have forwarded our correspondent's film clipping to the Universal Film Mfg. Co., with a report of the circumstances, and we have no doubt but what they will provide for more rigorous laboratory inspection in the future, because they have always co-operated with the members of the National Anti-Misf rame League in the past. With regard to the matter of carbons and carbon sizes, we believe that Mr. Fallon's views in this matter are now well understood by all the readers, but, as the present correspondent says, the experience of other operators on this matter is always useful for study and comparison. In the majority of cases where D. C. is used for projection, the arrangements are such that a great deal of electrical energy is lost in resistances of some form or another, and it is possible that the carbon manufacturers recommend upper carbons for amperages up to 45-50 because they represent less additional resistance in the circuit than would be the case if larger carbons were used for the same current — the final result representing slightly greater efficiency in the case of the smaller carbons. There is no doubt whatever that a satisfactory light in all respects can in many cases be attained with a 5^" cored upper carbon at 45 amperes, but on the other hand cases are known to all operators of experience where a larger upper carbon was required to produce a well-behaved arc, just as in the case of our correspondent. As it is the screen results, rather than small differences in relative efficiency, which are of chief concern to the average operator and exhibitor, we believe that most any operator would follow Mr. Rosecrans' procedure of increasing the upper carbon size, if a superior control of the light for the same amperage was thereby to be attained. When it comes to increasing the amperage also, in addition to increasing the carbon size, we doubt that there is anything actually gained above 45 amperes. The brightness of the D. C. arc crater becomes a constant at considerably below that amperage, and the uncorrected condenser system cannot efficiently image the enlarged craters formed at high amperages, but this is another line of consideration, not raised by our correspondent. We heartily endorse all of Mr. Rosecrans' good, sound, sensible remarks about the desirability of operators and managers frequently communicating their experiences and their difficulties to the Projection Department, and we stand ready to publish, advise and comment upon them at any time. Mr. Rosecrans sets a good example; let others follow it by bringing up for attention and discussion any subjects whose elucidation will be of benefit to all the operators. Discolored Light with A. C. Mr. Jacob Sheetz, Allentown, Pa., writes as follows: " I am using White A. C. Carbons on a Bell & Howell Compensator on 40 amp., and I get kind of a pinkish bluish light when projected on a gold-fiber screen. When I press the carbons closer together the light changes to a yellowish or very light brownish on the screen. However, I keep a short arc on A. C. What causes this? Have the carbons a natural tendency to give such a light for they should give a very soft snow white color, and a very bright screen illumination? "How can I coat a screen, just a regular muslin screen, in order to make either a silver screen, or a gold fiber. Can it be made by using silver glaze, or aluminum and bronze for a gold fiber?" In reply: We do not think the correspondent can blame the discolored appearance of his screen illumination to the brand of car bons used; it is more likely that his method of setting them is at fault, or that his projector optical system can be adjusted to produce a more satisfactory screen result. If the A. C. arc is so trimmed that images of both the upper and lower carbon tips are in focus simultaneously at the cooling plate there is generally a bluish streak across the center of the screen, and as this can hardly be avoided when the light from both carbon tips contributes to the spot, it is generally necessary to utilize the light from only one carbon tip for projecting the pictures, and if this is done, the discolored streak across the screen of course disappears. If only one of the incandescent tips of the A. C. arc is to be used, it is naturally more convenient to use the tip of the upper carbon as light source. This is accomplished by advancing the position of the lower carbon, as with the D. C. arc ; thus the lower carbon tip will be far out of focus when the tip of the upper carbon is clearly imaged on the cooling plate. If the illumination furnished by the upper carbon tip alone is not sufficient at the screen, then the amperage must be increased. The brownish appearance of the screen illumination mentioned by the correspondent is the natural result of feeding the carbons too close together. Considering further the bluish tinge in the light of which the correspondent complains, this may be due to other reasons than the one already advanced. If too great a distance is maintained between the carbon tips, then there will be some flaming of the carbons, and the blue or violet color of the arc flame must naturally be apparent on the screen. The arc flame will always cause a blue spot in the vicinity of the center of the screen if the condenser distance is such as to focus the carbon tips (or crater with D. C.) at the aperture of the projector, but in such event the ghost may be made to disappear by suitably altering the condenser distance. We will not publish instructions for the preparation of metalcoated screens by exhibitors, as the results of such attempts seldom justify the time and money expended, and suitable screens of this variety are on the market in abundance, and at fair prices. If an exhibitor has plenty of current available for projecting he will probably do as well with a white plaster or similar screen as with any other, but a plain muslin curtain is, of course, very wasteful of light, because a great deal passes right through instead of being reflected back to the eyes of the spectators. Numerous Simplex Installations in the Service IN the short time that J. S. Cifre has been connected with the 1 Boston Motion Picture Supply Company, 197 Pleasant street, Boston, Mass., exclusive distributors for the Simplex projectors in Massachusetts, Rhode Island and Connecticut, he has made a number of installations of this make in New England. Among the machines installed by him in September were three type " S " Simplex, motor driven, projectors at the United States Naval Training Station, Newport, R. I. Spotlights and booths were supplied with two of the machines which were installed in what is known as Destroyer Hall, a building two hundred and fifty feet by one hundred feet wide, with a fully equipped stage, and the third machine was placed in the Barracks " B " Building. One Simplex was already in use there. The films for both halls are booked by Lewis Astor, a sailor, who before entering the service, managed seevral theatres in New Orleans and its suburbs. The Destroyer Hall opened with " Hearts of the World," and as in the case of the Barracks " B " Building, shows pictures every night in the week for the benefit of the men in "the service. The machines are operated by two sailors, Arthur Martin, a member of Local No. 306, N. Y., and Sid Garwood. Two other naval installations have been credited to Mr. Cifre's efforts in the last month. He installed a Simplex, motor driven, machine on the U. S. S. Savannah, and also a type " S," motor driven, Simplex on the U. S. S. Delaware. While providing Uncle Sam's sailors with the means of seeing pictures, he did not neglect the boys in the army. He placed a type "S," motor driven, Simplex in the Christian Federation House, a finely appointed hut used for the entertainment of the soldiers at Camp Devens, Mass. Among the theatre installations made by him is the Orient Gardens theatre, East Boston, Mass., which purchased two Simplexes. The owner is James F. Powers, who also owns the Congress Hall theatre, South Boston, Mass. The Orient Gardens theatre is a cozy family house, with a seating capacity of about one thousand, and ranks with the best equipped theatres of that locality.