76. Charles Pritchard's photographic image of Perseus cluster, 1885

Charles Pritchard, the Oxford Savilian Professor of Astronomy pioneered the photographic measurement of stellar parallax (the device he designed is in the Museum's collection). Little can be seen on this glass negative with the naked eye. It was taken with the De la Rue reflector at the University Observatory. Exposure time was 30 minutes. The orientation in the sky is indicated by the small labels of the compass points.

Negative dry-plate 133 x 140 mm (including frame).