Thomos Royds received DSc (1912) from University of Manchester, UK. He was Director, Kodaikanal Observatory, Tamil Nadu (1923); and also Professor of Astronomy at Istanbul (1942).
Academic and Research Achievements: Professor Royds worked on the periodicities of prominences and their distribution on the solar disc. He carried out a long series of comparative studies between the spectra of laboratory arc lamps and the Sun. His detailed investigations of the shift of solar lines between the center of solar disc and at the limbs are considered significant contributions to solar spectroscopy. He undertook a crucial experiment during the total solar eclipse of 19 June1936 in Japan where he found that the differences of shifts for lines of different intensities were maintained right up to totality, and were more than the values predicted by the theory of relativity. He was also interested in spectroheliograms. He studied the heights of dark markings on the solar disc, their distribution and changes in orientation with respect to the solar meridian at different heliocentric latitudes and phases of the solar activity cycle, and explained these changes in terms of differential rotation of solar gases.
Awards and Honours: Professor Royds was elected Fellow of the Royal Astronomical Society.