day in homes all over the land the smaller movie cameras and projectors give happiness to the entire family the pictures which we take a pledge priceless memories of the changing ye this picture certainly seems to move by stopping and starting the action we see that it is really the result of a series of slightly different pictures passing quickly before the an optical illusion created by our persistence of vision you can in the infancy of movies this principle was adapted with paper pictures of progress of action run rapidly on or about going we'll for an audience of one in the historic scene shown here appears the inventor of the first talking motion picture thomas edison reading some of his fellow pioneers in the march of the movie drawings from which animated cartoons are made show up our first systems of vision is applied to the screen there is no more motion in any one of these drawings than on  postage stamp but on each one the action is slightly advanced if the series is split fast enough the picture seems to move these pictures are photographed and printed on a long transparent strip of celluloid film when run in a projector they come to li let us look behind the scenes as we greatly slow down the running scene normally the shutter revolves well over four thousand times a minute here numbers take the place of pictures so that you can readily follow the film as it moves when the black blade momentarily obscured the line part of the shutter blade is now removed so that you can watch the shuttle to that word no but the stroke that shifts the film is a cycle of four separate clearcut movement  him down then out and back up a shutter revolves three times for every picture change just cutting down each doctor area to less than five one thousandth of a second this gives added billion gradually now let us bring the speed up to normal twenty four pictures every second here we have repeated each number twenty four times so you can watch it change the film moves freely and a channel it is held steady by side tension scratches are both avoided because there is no pressure on the delicate film the camera used to photograph this picture works very much like the projector except that the light from the outside reaches the center the film through or sharply focused plan precision of the camera must be matched by the accuracy of the perforations in the film these punches produce the sprocket holes that control all film movement through every subsequent mechanism a steady running camera and accurately punched film make it possible to superimpose two pictures to form a single composite scene here's a good example the actors were photographed in hollywood the background a street scene was taken in another city the slightest movement er either camera would have spoiled the interesting effect now let us see what makes the movies top the sound is reproduced from a track on the side of the picture this is a variable density tried one of the two sound systems in general use and this is a variable area trial is a can be reduced to the smaller sixteen millimeter film their operation in the sound projector is similar the film passes through a sh beam of light coming from the excited land with the volume control please turn this light up and the sound becomes louder as the soundtrack of the film passes through the beam it creates a constantly changing light us see how the sound was actually photographed on this film the recording of my off screen voice such as you hear on newsreels for instance is done after the picture film is edited we are testing and getting ready to recall in the recording room  i am here with a microphone reading from my script against the picture action on the screen if my voice sets in motion air particles which strike the sensitive diaphragm with a sound wave pattern that is transmitted in corresponding electrical vibrations these are increase in volume thousands of times in the amplifier always variable area recording they must attain sufficient strength to vibrate a tiny mirror which reflects a ribbon of light through the optical system to create a constantly changing vibration pattern on the sensitive film my words that have been recorded on the soundtrack appear like this as i am now speaking to you from the screen many of you perhaps never realize that voice and sound can actually to be seen with arms screens around the picture and sound negatives are made at the same time so that the action and voice are exactly matched in hollywood at the grand national studios we see a well known developing of the negative film is done in intricate machines but the basic principle involved is much the same as the way you develop a snapshot into solutions and watch water the picture is then printed after the print is developed it is cotton edited often from as much as a quarter of a million feet of the supposed they own less than eight thousand feet will be selected to make up the finished picture then the picture negative and soundtrack negatives are matched and printed together on a single film called the composite print this is a completed production finished the real audiences and there is all over the world for smaller projectors sixteen millimeter prints of the same pictures are made from the standard negatives on a reduction printer because the smaller prints are less than one fourth the area of the status extreme accuracy is absolutely necessary for good result here is a ten wheel feature production on thirty five millimeter film which when reduced to sixteen millimeter gives us an equal amount of picture with less bulk less weight and absolute safety from biohazard you can now buy or rent hundreds of these motion pictures silent all with sound education subject to hollywood features it is possible for anyone to show motion pictures anywhere any time because we have a  sixteen millimeter projectors meeting every owner and audience requirement the magic pictures of moves and talk now comes to your screen at your com