Technical aspects
Animation works because of a physiological condition called as the persistence of human vision. Every image that falls on the retina is retained for a short instant of time. If this is replaced by a series of almost similar images, each slightly different from the preceding one, they create a sense of motion.
In 1872, Eadweard Muybridge, created a set of remarkable photographic images by taking pictures of moving animals photographed at short intervals. Seeing these 'nearly identical' images one after the other through some device such as the phenakistoscope creates an illusion of motion.
Animation before animation-films
Before the invention of film, animated images were created through many devices such as the Thaumatrope (1824), the Phenakistoscope (1831), Zoetrope (180 AD; 1834), Flip book (1868), Praxinoscope (1877)
Thaumatrope (Sir John Herschel, 1824)
A thaumatrope uses a circular disk with two different pictures on each side. A string through the centre is twirled so that the two pictures appear to combine into a single image. If a hat is drawn on one side and a man's head (in an appropriate position) on the other side , twirling would create an image of a man weraing a hat.
Phenakistoscope (Joseph Plateau, Simon von Stampfer, 1831)
The Phenakistoscope is a disk with images, around the center of the disk. Slots cut out of the disk enable the viewing of images as the disk is rotated. The illusion of animation is created with the help of a mirror that reflects the drawings as they move past the slots.
Zoetrope (William George Horner, 1834)
The zoetrope operates on the same principle as the phenakistoscope but does away with the require the mirror and allows several people to view the animation.
Flip book (John Barnes Linnet, 1868)
A flip book is a small booklet, bound on one edge. An action sequence is drawn near the unbound edge, over a set of pages. Each frame differs marginally, from the previous one. A viewer bends the book and releases the pages so that each image appears momentarily and creates an illusion of motion. For example a flip book sequence of a bud blooming into a flower could begin with a drawing of the bud and over a set of frames bloom into a fully-opened flower. Flipping the pages of the book creates an animated effect of the bud blooming open. Pages that are slightly stiff make the flipping action easier.
Praxinoscope (Charles-Émile Reynaud,1877)
The praxinoscope combines the cylindrical design of the zoetrope with the viewing mirror of the phenakistoscope.
