MOVING PICTURES 



MOVING PICTURES 



have been visible only one-tenth of that time. 

 This fact is known as persistence of vision, and 

 IT is the principle on which moving pictures 

 are based. Although pictures are said to be in 

 motion on the screen, as a matter of fact 

 there is no motion at all. The eye imagines it 

 sees movement. But what it actually sees is a 

 series of pictures which are stationary on the 

 screen for an instant and whose movement out 

 of sight is concealed from the eye by a swiftly- 

 moving shutter which cuts off all light from 

 the screen for a brief instant. The eye, being 

 more susceptible to light than to darkness, 

 records only the pictures and not the interval 

 when the screen is black, and an effect of mo- 

 tion is thus produced. 



The fact of persistence of vision was first 

 noted by Lucretius, a Roman writer, in the 

 year 65 B.C. Ptolemy, a Greek philosopher, 

 noted the same principle about two hundred 

 years later, and proved it by means of a re- 

 volving card on which a series of dots took the 

 appearance of a continuous line. Every child 

 who has whirled a burning stick to produce a 

 ring of fire has had proof of the same principle. 

 No use was made of this principle until 1825, 

 when a child's toy was invented which con- 

 sisted of an oblong card with pictures on both 

 sides, which was turned by means of a string 

 so that the two pictures gave the appearance of 

 one. More elaborate toys were later invented, 

 one known as the phenakistoscope, another as 

 a zoetrope, which utilized the same principle. 

 In 1884 a contrivance called a choreutoscope 

 was invented for use in a stereopticon lantern. 



is a plate painted with figures which moved 

 in a sliding frame so that a series of images 



ii appeared to be in motion were cast on 

 the screen. This was, in fact, an actual moving 



ire. 



The Earliest Photographic Moving Pictures. 

 In 1872 Eadweard Muybridge, an Knglishman, 

 secured a number of photographs of the con- 

 secutive movements of a trotting horse by set- 

 tm up a series of cameras along a race track, 



h were operated by a string broken by tin 

 passage of the horse along tin- truck. These 

 pictures were made in California and were first 

 /I in America in 1879. In 1882 they 

 were shown at the Royal Institution in Lon- 

 don. M .-. M-idge's method of obtaining these 

 pictures was very clumsy and was quickly sup- 

 planted by 01 , I. J. Marey. in 

 Paris, had begun experimenting with the photo- 

 graphs of animals in motion, and in 1876 he 

 perfected a camera which was known as the 



Marey photographic gun, which took a dozen 

 pictures of an object in rapid succession. By 

 1889 celluloid film had been invented. W. 

 Friese Greene and M. Evans in the same year 

 filed for patent several specifications for a 

 camera which utilized this film and which was 

 capable of taking three hundred exposures at 

 the rate of about ten a second. As soon as the 

 Friese Greene camera had appeared, inventors 

 in France, Germany, England and America 

 were simultaneously working at the problem of 

 perfecting similar cameras and projecting ma- 

 chines. 



In America Edison was first with his kincto- 

 scope, which was patented in 1893. In the same 

 year he gave his* first exhibit at the Brooklyn 

 Institute. The pictures projected by this ki- 

 netoscope were viewed by one person at a time, 

 looking through an eye aperture. In France, 

 G. Demeney perfected a machine which he 

 called the chrono-photographc, which he pat- 

 ented both in France and in England, in 1893. 

 The biograph was the name given to a machine 

 invented by Herman Casler of Canastota, 

 N. Y., a projector which used larger pictures 

 than the size standardized by Edison. From 

 this time on the work of perfecting the me- 

 chanical devices for taking pictures and pro- 

 jecting them was carried on with the spectacu- 

 lar results that have already been noted. 

 The Camera. The typical moving ; 

 camera is rectangular in shape. An average 

 size is t \\vnty-four by fourteen by five inches. 

 There are larger cameras than this, of course, 

 and others which are much smaller. The Wil- 

 liamson camera, for instance, is nine and one- 

 half inches square by four and three-fourths 

 inches deep, and weighs only seven and one- 

 half pounds, including tin- !m. The 

 camera case is usually made of polished wood, 

 very strongly put together, with a handle for 

 carrying. Although there are dozens of differ- 

 ent makes of cameras on the market, ranging 

 nil fh< way from 180 to $1,000 in price, they 

 all operate on the same prin< 



essential feature of a camera is that it 

 shall take a series of snapshots in rapid succes- 

 sion, with an exposure brief enough to record 

 no i blur, on a continuous length of 



film Thin film must be made to move before 

 th. lens <>f the camera in a regular series of 



S at the exact instant when the shutt. 



camera opens and closes, this film must be 

 absolutely at rest and then it must n 

 abruptly onward to bring into position the 

 next space which is to be exposed. 



