Herbert Stanley Allen FRSE FRS[1] (29 December 1873 – 27 April 1954) was an English physicist from Cornwall noted as a pioneer in early X-ray research, working under J. J. Thomson at the University of London and alongside Nobel laureate Charles Glover Barkla at the University of Edinburgh.

[2] As an undergraduate at Trinity College, Cambridge, Allen shared Whewell's Court with fellow pupil Edmund Whittaker, earning his Mathematics B.A.

[3] After working at Cavendish Laboratory, Allen returned to Cambridge in 1898 to conduct research under J. J. Thomson on the motion of spheres through viscous fluids, useful in the determination of the elementary unit of charge.

[1] Allen's 1913 book, "Photo-electricity",[5] was an early contribution to the study of radiation, focusing on his earlier work in photoelectric fatigue.

[18][19][20][21][22][23][24] Fellow academic Sir D’Arcy Thompson said of him, "Perhaps he does not realize how strongly he has endeared himself to his colleagues and his students by his own personality, his faith and vision…"[25] Allen died 27 April 1954 at the home of his daughter in Balblair, Ross-shire, Scotland.