This solar photograph, in white light, shows the whole disc of the Sun on 12 August, 1917. Taken using the 60-Foot Tower Telescope at Mount Wilson Observatory in California, United States, it shows a large group of sunspots lying close to the Sun's equator. Completed in 1907, the solar telescope was designed by the American astronomer George Ellery Hale (1868-1938) who established the observatory three years earlier. Dimensions: 381mm x 482mm.
© Science Museum / Science & Society Picture Library