James Prescott Joule (1818-1889), seated, facing right. Photograph by L. Roscoe, c. 1890.

The photograph is one of a collection depicting Sir Arthur Schuster (1851-1934), his family and friends. Sir Arthur, a British physicist and professor in applied mathematics and physics at the University of Manchester, was a pioneer in spectroscopy and terrestrial magnetism, inventing the Schuster-Smith magnetometer, a standard instrument for measuring the earth's magnetic force. This photograph and others (mostly depicting his work with x-rays) were presented to the Wellcome Institute by his daughter, Dr. Nora H. Schuster, in 1962