Stereoscopic photograph of a sacrifice scene in the Kalighat Temple at Calcutta in West Bengal, taken by James Ricalton in c. 1903, from The Underwood Travel Library: Stereoscopic Views of India. This image is described by Ricalton in 'India Through the Stereoscope' (1907), "We are in the inner courtyard of the well-known Kalighat temple...We can see at the right some steps leading up to the main portion of the temple. To the left are a number of timorous kids or half-grown goats bleating an unheeded appeal. The bystanders are attendants and those who have brought sacrifices...The principal religious festival of the year takes place on the second day after the Darga Puja, when the temple is visited by thousands of pilgrims." This is one of a series of 100 photographs, designed to be viewed through a special binocular viewer, producing a 3D effect. The series was sold together with a book of descriptions and a map to enable the 'traveller' to imagine that he was 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.