Stereoscopic photograph of a Hindu cremation site at Bombay in Maharashtra, taken by James Ricalton in c. 1903, from The Underwood Travel Library: Stereoscopic Views of India. This is a view of a Hindu cremation site with eight or ten pyres, each shielded form the wind by a square screen. Ricalton explains in 'India Through the Stereoscope' (1907) that he requested that one screen be removed to reveal a pile which is beginning to burn. This is one of a series of 100 photographs, designed to be viewed through a special binocular viewer, producing a 3D effect. They were sold together with a book of descriptions and a map with precise locations to enable the 'traveller' to imagine that he was really 'touring' around India. Stereoscopic cameras, those with two lenses and the ability to take two photographs at the same time, were introduced in the mid 19th century and revolutionised photography. They cut down exposure time and thus allowed for some movement in the image without blurring as subjects were not required to sit for long periods to produce sharp results.