Steve Lowery, age 14, of Charlotte, N.C., for his question:

WHO INVENTED THE MOVIE CAMERA?

Movies and motion pictures are made by a camera that can take many still pictures rapidly. One picture after another is recorded on film. These pictures are then shown in a projector which flashes them on a screen so.fast that they seem to blend into one continuous movie. Ancient Egyptians knew that seeing a series of pictures in quick succession would give the illusion of movement. But it wasn't until 1824 that Dr. Peter Roget, in England, suggested that the use of the principle of persistence of vision might result in moving pictures.

His theory: The viewer's eyes play a trick as still photos pass quickly. A person sees something when it is no longer there. Each picture shows a slightly more advanced step of some act of motion. The image of the first picture stays in the eyes until the second picture is seen, causing each to blend into the next.

Dr. Roget's work led in 1830 to the development of two machines in which series of pictures showing motion were viewed through slits in a rotating disk.

In the 1870s, a man named Muybridge was the first to successfully photograph motion when he used many separate cameras to take pictures of a running horse. Then Eastman perfected photographic roll film in 1888 and shortly after this Edison produced his kinetograph, a machine which took series of pictures on a roll. Edison also came up with the kinetoscope, a machine for viewing the pictures. The viewer turned a large wheel on which hundreds of photographs flipped by, each lighted for just a second.

Men named Jenkin and Armat came up with projectors in 1894 and 1895 that moved long films of thousands of photographs past a projecting lens, making it possible for large audiences to see a movie together.

Many changes and improvements have been made in film, cameras and projectors during this century. Sound came along in the late 1920s and color in the 1930s. Three dimensional effects were also perfected.