This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Loading Roll Film In Kodak. No difficulty will be experienced if, in loading the roll into the kodak, you follow the instructions which accompany each roll of film. If the spool does not slip into place easily you no doubt are handling it so that the ends of the spool are not parallel with the sides of the camera. It is necessary, in some of the types of kodaks, to pull out or turn to the left the little pins which hold the film in place. These pins extend through each side of the camera and must be withdrawn previous to the insertion of the spool. The spool will then drop into its proper position; after which the pins are turned or pushed in so as to fit snugly into the center of the spool. After tearing loose the paper band that keeps the black paper from unwinding, unroll enough of the black paper to reach the winding spool, and as soon as you have fastened it into this spool, give it a couple of turns.
228. The back is now replaced so as to exclude all light from the interior. Keep on turning the spool until you see in the little red window the hand or the number 1; if instead of a number a white surface suddenly comes before the red window, you may know immediately that you have placed the roll of film in the holder wrong. The film, in place of drawing from over the top of the roll, is very likely drawing from underneath; consequently the film side of the roll is facing out instead of in toward the lens; in other words, the black paper is between the film and the lens. Before winding any further from the spool, take the camera to your dark-room and remove both spools; wind the black paper and film back to the original spool and then reinsert the spools in position properly.
Winding Film In Kodak. Illustration 26 a shows a section of film which was not wound tightly on the spool, the portion of it buckling outward, thus admitting a streak of light which caused the fog across the middle of the film negative and also the fog at the sides. Care must always be exercised to keep the spool tightly wound in the camera and also tightly wound when removing it from the holder. Immediately after removing the exposed roll from the camera fasten the end of the black paper with the strip of gummed paper which accompanies the spool; or you can use a rubber band. Previous to inserting the roll of film in the camera, be sure that the shutter is closed; for, after you have placed the film into position for the first exposure, should the lens be opened you will immediately fog the film. Having once unrolled the film the shutter must be always kept closed, except when making exposures.
Double Exposure On A Film. After you have made the first exposure, turn the winding key until the figure 2 appears at the little red window, at the rear of the camera, indicating that the film is ready for the next picture. Should you neglect to turn the film immediately after making exposure, you are very apt to make a double exposure on the section which has already been exposed.