After the foundation of the Natural Sciences Tripos in 1851, the University of Cambridge found itself in need of a laboratory dedicated to experimental physics. As Chancellor of the University of Cambridge from 1861 to 1891, William Cavendish, 7th Duke of Devonshire, agreed to fund such a building. One of his conditions was that the colleges would endow a professorship for the new foundation. Thus was born the Cavendish Professorship of Experimental Physics. The first five holders of this position were members of Trinity College.
The first professor, appointed in 1871, was James Clerk Maxwell, a Scottish scientist and Fellow of Trinity College best known for his research on electromagnetism, though he worked on many more subjects, from colour vision to the nature of Saturn’s rings. He helped to plan and design the building, while introducing an innovative course in scientific measurement. He published his best-known work – A Treatise on Electricity and Magnetism – in 1873 and finished his edition of the works of the natural philosopher Henry Cavendish (1731-1810) shortly before his death in 1879. The laboratory was named after Henry, an ancestor of William Cavendish the 7th Duke.
Maxwell was followed by John William Strutt, 3rd Baron Rayleigh, who held the Professorship from 1879 to 1884. Rayleigh re-equipped the laboratory and modified the practical course put in place by his predecessor, appointing two new demonstrators to design a new series of set experiments. He also allowed women to study alongside men in the laboratory for the first time. A past student and Fellow of Trinity, he became an academic advisor to his future successor, Sir J. J. Thomson.
Thomson first entered the Cavendish as a student in 1880 and became professor four years later. He held the position until 1919, a year after he became Master of Trinity College. The laboratory was extended twice under his professorship. His research led to the first example of mass spectrometry, which proposed a new model of the atom – the ‘plum-pudding’ model – and the creation of the concept of electromagnetic mass. He received a Nobel Prize in Physics in 1906.
In addition to his personal contributions to science, Thomson also taught a new generation of researchers, including both of the next Cavendish Professors. Eight of his students, plus his own son, were awarded Nobel Prizes in either physics or chemistry. He was succeeded as Cavendish Professor by Ernest Rutherford, 1st Baron Rutherford.
Rutherford led the Cavendish for eighteen years, from Thomson’s departure to his own death. Rutherford worked on radioactivity, earning the Nobel Prize in Chemistry in 1908 for discovering the principle of the ‘half-life’. He also distinguished two types of radiation as early as 1899, naming them alpha and beta ray, and refined Thomson’s model of the atom.
His tenure saw many more discoveries, from the isotopes of the chemical elements by F. W. Aston to the first controlled nuclear disintegrations by John Cockcroft and Ernest Walton. He taught, amongst others, Harriet Brooks, the first Canadian female nuclear physicist and Hans Geiger, creator of the Geiger counter. Ten of his students received the Nobel Prize.
Sir William Lawrence Bragg, the youngest science Nobel Prize winner replaced Rutherford in 1937 as fifth Cavendish Professor. Considered a pioneer of crystallography which he developed with his father, his research also included sound ranging and some work on sonar for the army. As professor, he secured more funding for members of the Cavendish, funding research which led to the decoding of the structure of DNA, haemoglobin, and myoglobin. He left the Laboratory in 1954.
Sixty-five years on, the Cavendish Laboratory continues its pioneering work in the field of physics and related subjects. The work done by these five Cavendish Professors, not only as eminent scientists but also as teachers, formed the foundation of the reputation it enjoys today.
Trinity College Library, Cambridge 