The wheel principle would have to be given up and a long strip with pictures would be needed.

That presupposed a correspondingly long set of exposures and this demand could not be realized as long as the pictures were taken on glass plates.

But in that period experiments were undertaken on many sides to substitute a more flexible transparent material for the glass.

Translucent papers, gelatine, celluloid, and other substances were tried.

It is well known that the invention which was decisive was the film which Eastman in Rochester produced.