Charles Glover Barkla

In 1907, Barkla married Mary Esther Cowell. The couple had two sons and one daughter. The youngest of them was Flight Lieutenant Michael Barkla, who died in action in 1943. Michael was also a brilliant scholar and his untimely death affected Barkla to a great extent.

Charles Glover Barkla died on 23 October 1944 in Edinburgh, Scotland, at the age of 67.

Lunar cater ‘Barkla’, which has a diameter of 42 km and is located at 10.7° S, 67.2° E on the lunar surface, has been named in his honor.

Charles Glover Barkla was born on 7 June 1877, in Widnes, near Liverpool, England. His father, John Martin Barkla, was a secretary for the Atlas Chemical Company and his mother, Sarah Glover, was the daughter of a watchmaker.

Barkla had his secondary education at Liverpool Institute. In October 1894, he entered University College, Liverpool with a County Council Scholarship and a Bibby Scholarship to study mathematics and physics. Later, he concentrated on physics, studying the subject under Oliver Joseph Lodge, who was famous for his work on electromagnetic radiation.

In 1898, Charles Barkla received his B.Sc. degree with a First Class honors in physics. In the following year, he completed his master’s degree at the same institute. During this period, he also served as first president of the University Physical Society and occasionally, took classes in place of Professor Lodge.

In autumn of 1899, after receiving his master’s degree from University of Liverpool, Barkla joined Trinity College, Cambridge. Here, he started working on the velocity of electromagnetic waves along wires of different widths and materials, under J. J. Thomson, in the Cavendish Laboratory.

In 1900, after one and half years at the Trinity, Barkla shifted to King’s College, Cambridge. His main aim was to take part in its chapel choir. He had a baritone voice, which enthralled the audience and his solos filled up the chapel.

In 1902, Charles Glover Barkla returned to the University of Liverpool as Oliver Lodge Fellow and began his work on Röntgen radiation.

In June 1903, he established that secondary radiation emitted by all gases was of the same wavelength as that of the primary beam and that the scattering was proportionate to the mass of the atom.

In 1904, continuing his research on the same subject, Barkla showed that just like light, x-rays are also a form of electromagnetic radiation. His work during this period earned him his degree in Doctor of Science (D. Sc) from the University of Liverpool.

Subsequently in 1905, he was appointed as a demonstrator at the University of Liverpool; but within a short period became an Assistant Lecturer. Sometime in 1906, Barkla, along with his team, used X-ray scattering to determine the number of electrons in the carbon atom.

In 1907, he was made a Physics Lecturer in Advanced Electricity at the same institute. The post was especially created for him. He remained there until 1909.

Charles Glover Barkla is best known for his work on X-ray scattering. Starting his work in 1903, he established that X-ray scattering occurs when X rays are deflected by the atomic electrons, while they pass through matter. This technique proved to be particularly useful in the study of atomic structures.

Around 1906, he also showed that each element had a unique secondary spectrum, irrespective of its temperature, structure, and chemical composition. Its spectrum was therefore a characteristic property of an atom.

Later, he developed the laws governing the transmission of X-rays through matter, especially the principles of the excitation of secondary X-rays. In addition, he made significant input in X -ray spectroscopy.