The first workable photographic process was developed by the stage designer and showman, Louis Daguerre.

By the nineteenth century many people were familiar with the 'camera obscura' - a device for projecting an image onto a ground-glass screen. These were widely used by artists to assist in sketching views. Daguerre was one of several experimenters who had tried to capture the images they produced.

This Daguerreotype camera, made by the toymaker Alphonse Giroux, is from the first series made for sale. Most of these cameras were bought for commercial portraiture or to produce entertaining and saleable views of various types.

The process used a silvered copper plate sensitised with iodine. The plate was exposed in the camera and then developed with vapour from a warmed dish of mercury. Finally the image was fixed with strong sodium chloride solution (later sodium hyposulphite).

An enduring mystery is how Daguerre developed such an intricate process. François Arago, the eminent physicist, announced the discovery in 1839 and remarked on the 'inability of the combined wisdom of physical, chemical and optical science to offer any theory of these delicate and complicated operations'.

Inv. 1920-608