Developable surface (Math.), a surface described by a moving right line, and such that consecutive positions of the generator intersect each other. Hence, the surface can be developed into a plane.
... silver bromide molecule, whatever be its nature, is one of gradually increasing intensity, and finally attains a maximum when a return to the original condition occurs. The maximum is the point of most intense developable image. It is probable that the sensitiser—in this case the gelatin in which the bromide of silver is immersed—plays a part in the conditions of stability ... — The Birth-Time of the World and Other Scientific Essays • J. (John) Joly
...
