FILMSTATS, a NEW MEANS for the ADVANCEMENT of SCIENCE ATHERTON SEIDELI, National Institute of Health. Washington, D. C.
P
ROGRESS in science and industry is made by the extension and application of existing knowledge. Those engaged in research must acquaint themselves as thoroughly as possible with the recorded experiments of their predecessors. Any means of facilitating this task may be expected to contribute to the advancement of science. It is practically impossible for any person or institution to collect all the published data upon even a single branch of science. The largest libraries may not be provided with the literature of any considerable portion of science. The number of really noteworthy scientific reference libraries in the world is quite small. In the case of all collections of scientific literature their full use is restricted to those research workers who happen to be located in their immediate vicinity. There can be no doubt that large numbers of persons possessing the necessary training and skill to do creditable research, are prevented from exercising their talents in this direction by lack of access to collections of scientific literature. Those who make the effort, without a thorough knowledge of the literature, may waste their time in repeating the work of others. Even for those who do have access to libraries the physical effort incident to consulting the books in the reading rooms or of obtaining them by loan, is frequently a considerable task. The making of a digest of the pertinent data upon a given research problem requires a diligent, systematic, and often tiresome effort. It is toward the lightening of this burden nl;on the research worker that the film copying and distribution of scientific literature may be expected to contribute in a marked degree. The problem of furnishing to scientists copies of the particular documents required by them has for its basis the economical production of single copies of desired articles. Most duplicating processes provide multiple copies a t a unit cost which diminishes with the number made, but do not permit the production of single copies a t a sufficiently low cost. Photographing on moving picture iilm does, however, offer the possibility of meeting this requirement. The cost of the first copy is no greater than that of succeeding ones. By means of special cameras and equipment which have been developed in recent years, the reduced-size copies of documents upon standard moving picture film can now be made a t a price which is certainly within the means of practically everyone. At an exhibit of cameras designed for photographing
FIGURE
1.-GENERAL VIEW OF T I i C DRAEGER FILMsrnT CAMERA
printed pages upon moving picture film held in Washington, Dec. 27-29, 1934, five types were shown, namely, the Leica, the E.K.A., Recordak, the Draeger, and one being perfected by the Folmer-Graflex Corporation. The Leica camera has been on the market for a number of years and has been used with success by many persons. It is a multiple-service camera which with special equipment may be used for photographing the pages of books and similar material. Its particular utility, however, is in enabling individuals to copy the articles of which they may have need. Its limited film capacity and the several manipulations required in making the exposures, restricts its use for the large-scale production under which a library filmcopying service would be called upon to operate. The French E.K.A. camera was provided with the necessary accessories for copying documents by Paul Lemare of Paris and has been used for some years in the Library of Congress for copying manuscripts. It
does excellent work but it also is limited in the rate at which it can be operated. The Recordak was originally developed to permit hanks to keep a photographic record on 16-mm. film of paid checks returned to their customers. It has now been enlarged to copy typewritten or other material on sheets up to 8 X 10 inches in size. For this purpose the sheets are fed into an opening and photographed while in motion upon a rotating drum. The speed is therefore limited only by the rate a t which sheets can be inserted into a narrow opening. It has found numerous commercial applications and it is destined to be used on an ever-increasing scale in various trade and industrial enterprises. It is stated that the apparatus will eventually be adapted to photograph the pages of bound volumes. It is the policy of the manufacturers of Recordak to rent rather than sell their machines. The user therefore makes no capital investment and is assured of always being supplied with the latest and most perfect model. The rent is about $30.00 per month. The most highly perfected camera for photographing the pages of books is that invented and built by Dr. R. H. Draeger, a medical officer of the U. S. Navy. A photograph of this camera is shown in Figure 1. The assembly consists of a stout table with lamp boxes on either side, and, fastened to the rear center, an npright steel column. This carries a cross-arm from which the camera is hung. The latter consists of the film reels and housing, the film-winding mechanism, and the exposure chamber in alignment with the lens and shutter. The cauacity of the reels is 160 feet of filmsufficient for 1286 exposures. Since two printed pages are usually photographed a t each exposure one loading of the camera is sufficient for 2560 pages. The book to be photographed is placed in the space between the two lamp boxes. It is covered with a glass plate and the height of the page to be copied is measured. A table on the cross-arm shows the focal distance corresponding to Garious page sizes. The camera is set at this reading on the scale, the lens adjustment is made, and the bulb is pressed for the exposure. By this operation the lamps are illuminated and the shutter opened. Upon releasing the bulb the shutter closes and the motor which winds the film to the next frame is set in motion. For the next photograph the glass plate is raised, the page turned, the glass plate replaced, and the bulb pressed and released as before. It has been found that between 1000 and 1500 pages can be photographed per hour. Dr. Draeger is a t present building another camera which will be provided with reels of 1000-foot capacity, an automatic timing device for the exposure, an automatic focusing device, counter for number of exposures made, and an automatic page-turning mechanism. The fifth of the exhibits to which reference has been made was a preliminary model of a relatively simplified and inexpensive copying camera being developed by the Folmer Grailex Corporation of Rochester, New York. A view of this camera is shown in Figure 2. Its dis-
When dismounted everything except the two lamps and bracket fits inside the case, which serves as the base while photographing.
tinctive feature is the simple means of advancing the film after each exposure, T h i s is accomplished by a mechanism actuated by releasing the pressure on a small piston. The arrangement is such that by compressing the piston rod a timed exposure is made and upon its release a spring tension advances the film to the next position. Thus no ,electric motor is needed. The lamps illuminating the pages to be photographed are allowed to burn continuously so that a mechanism for their lighting and extinguishing is unnecessary. The operations consist therefore, as in the case of the Draeger camera, in measuring the book, focusing by means of a calibrated scale, covering the pages with a glass plate, making the exposure by pressing and then releasing a small piston, lifting the glass plate, and turning to the next page. These two highly specialized cameras provide a practical and simple means of photographing very rapidly the pages of bound volumes. Thus it is now possible for libraries to obtain at a reasonable outlay the necessary equipment for setting up a service of film copying of scientific and other documents. The organization of such a service is not a complicated matter. The camera requires very little space and its operation may be learned by persons of normal intelligence within a brief time. The developing of the reels of film is also a relatively simple matter and requires no special equipment other than the usual
dark room and photographic chemicals. The most convenient means of holding the film during immersion in the developing and fixing solutions is by winding it on a metal helix or a similar device. After thorough washing it is dried upon wooden frames and then cut in lengths corresponding to the various articles copied. For brevity and convenience it is proposed to designate film copies of printed and other matter as "Filmstats." This word will avoid confusing such photographic copies with the widely used name "Photostats" for copies on paper. A senice of the kind described above has been in operation in the Library of the U. S. Department of Agriculture in Washington for several months under the name "Biblio Film Service." The filmstats made by this service are sold a t 10 cents per article of 10 pages or less, and 5 cents for each additional 10 pages or fraction thereof. The experience, so far, indicates that this price is ample to meet costs of the service and provide for the purchase of additional equipment as needed. Naturally without means of reading the greatly reduced-size print upon 35-mm. filmstats, the service would be of no value. It is also important that the magnifying or projecting devices for this purpose shall be within the means of the individuals for whose benefit the service is organized. It has been found that a very simple magnifier of the reduced print can be made by mounting an 8- to 10power inexpensive lens in one end of a short cylinder, and two plates between which the film is held perpendicularly to the lens at the other end. A ground glass beyond the film equalizes the illumination of the print. Views of such a reading device, made by the Spencer Lens Co., Buffalo, N. Y., are shown in Figure 3. Such a simple magnifier as that just described, which can be produced for about $5.00, is naturally suitable only for very limited use. It may serve in the beginning as a temporary expedient and permit those who have only a very slight need of filmstat service to make preliminary experiments which will indicate its possible value to them. + What is essential to the widespread and extensive use of filmstats is a projecting device a t a moderate price which will permit reproducing the printed matter in approximately the same size as the original and under reading conditions similar to those under which ordinary printed matter is read. The various types of projecting apparatus so far prodnced have generally been designed for pictorial reproduction to be viewed by groups of persons. Their focal lengths are usually greater than will permit projecting reading matter a t close range. Furthermore, the intensity of the illumination is such that the accompanying heat is in practically all cases sufficient to damage the film within a very brief period. The filmstat therefore cannot be projected for as long a time as may be necessary for its careful study. The modifications which would be required to adapt existing models of projectors to filmstats are so great that it has seemed best to design an entirely new ap-
paratus for the convenient reading of the texts photographed upon the narrow film. As has been implied, such a new apparatus must fulfil several essential conditions. The image should be bright enough to be read in ordinary diffusedlight. It must be projected a t sufficiently short range to make it unnecessary for the reader to change his position in order to move the filmstat to the successive positions corresponding to the sequence of the text. The lens should give a sufficiently large area of sharply defined image. The heat from the lamp must not damage the film during as long a period as one may desire to project it. Finally it should be compact and capable of production at a cost which is not beyond the means of most individual users.
h F I G ~ E3 . - ~ 1 e w s OF A FILMSTAT MAONIPIER MOUNTED ON A STAND AND HELDIN THE HAND
Considerable attention has been given to this problem and an apparatus designed which. fulfils the above requirements in practically all respects except possibly that of sufficiently moderate cost. It has been found that a high-grade photographic lens is needed to give the required sharpness of definition over the desired area of field. Such lenses are rather expensive and i t is this element of cost which limits the cheapness a t which the apparatus may be produced. Two experimental models have been developed. In both cases the projecting apparatus is the same, but in one case the image is received directly upon a screen mounted in the larger end of a box, and in the other is reflected from a mirror to a screen tilted at the angle most convenient for reading. The disadvantage in the first case is that the position of the filmstat, with respect to the reader, is somewhat too distant to permit its manual displacement without bodily movement. In the second case, in order to avoid haziness resulting from double reflection from an ordinary mirror, a surface reflecting mirror is necessary, and these are usually subject to rapid deterioration and accidental damage. The projector itself is made up of four elements: the electric lamp, the light-condenser lenses, the filmstrip holder, and the projection lens. There are several novel features by which the necessary conditions of satisfactory projection have been attained. The arrangement of the condenser lenses is such that a suf-
ficient distance between the source of light and the filmstat is secured to provide for an open air space which permits the dissipation of much of the radiated heat. The heat transmitted by the metal walls is diminished by a reduction in the cross-section of the metal part and the interposing of a non-heat-transmitting collar. The light is first condensed partly by two 85-mm. focal length plano-convex lenses. About 85 mm. in front of these it is further condensed by a 51-mm. focal length plano-convex lens, immediately adjacent to which is placed the filmstat. This cone of light thus passes
immediately through the film and converges a t the center of the projector lens about 35 mm. distant. A mirror reilector has been found inadvisable since more heat than is permissible is concentrated upon the film. The most satisfactory filmstat projector so far developed is the one shown in Figure 4, now being made by the Spencer Lens Co. It is provided with a first surface mirror protected by folding covers and the projecting unit itself folds into the box when not in use. The film holder is open a t the top and permits inserting the filmstat without threading through a narrow opening. The lens is of such excellence and covering quality that an entire page is projected in approximately its original size and may be read without displacement of the film. The heat radiation from the lamp is so successfully controlled that the film may be left indefinitely in the apparatus without damage. The progress which has so far been made in the perfection of cameras for rapidly photographing the pages of books upon 35-mm. film and the development of satisfactory magnifying and projecting devices for reading the filmstats is such that the widespread,application of this process to the dissemination of scientific and other literature may now be expected. There appears little doubt that the development of this service will become of far greater utility than it is now possible to predict. Many applications not apparent a t present will certainly be found and it is reasonable to expect that film copying will gradually revolutionize the existing methods of distributing scientific:and other recorded intelligence.
