Obituary: Paul Vigoureux

PAUL VIGOUREUX'S work had a profound impact on the exactness of science and technology. Through it, and in the translation of key documents between French and English, he helped greatly in the process of reaching agreement as to what the International System of Units, the SI, should be. Where necessary he would gently remind over-enthusiastic pedants that "units are made for people, not the other way round".

He was born in Mauritius in 1903, and came to London to study, winning a scholarship to the City and Guilds College in South Kensington. After graduating in Electrical Engineering he went on to acquire post-graduate qualifications, followed by a long and productive research career at the National Physical Laboratory and with the Admiralty Scientific Service.

Aside from his wartime work in submarine detection, Vigoureux made notable contributions to the units of electricity and magnetism - particularly to the shape and introduction of the SI units. He authored and co-authored a number of scientific papers and several technical books, and one on cookery, Cook It the French Way (with Barbara Wilcox, 1949), which included many of his mother's recipes. He spent his career in the United Kingdom Scientific Civil Service, initially and latterly at the National Physical Laboratory (NPL), with an intermediate period in the Admiralty Scientific Service.

Vigoureux devoted much of his life to metrology, the science of exact measurement, at the National Physical Laboratory. He began with electrical measurements, working with D.W. Dye and J.E. Sears (two of NPL's contemporary giants of metrology) on improving the Ayrton-Jones primary electrical standard current balance. He also worked with Dye on the quartz crystal technology, which is found in nearly every wristwatch today; the Institution of Electrical Engineers awarded him its Duddell Premium in 1930 for a paper on the subject. His book on quartz crystals, Quartz Oscillators and Their Applications (1939), is a monument to his early ultrasonics interests. (Quartz oscillators were used for medical ultrascans, echosounding and clocks.)

In 1935 he played a part in helping Sears to break the international deadlock which was preventing the introduction of the Giorgi metre-kilogram- second (MKS) system of units - resulting in the committee concerned voting for one solution but actually recommending the one put forward by Sears! With Clifford Webb he wrote a classic book on electricity and magnetism, Principles of Electric and Magnetic Measurements (1936), which anticipated the global adoption of the MKS units in 1948 as the SI, in place of the centimetre-gram-second (CGS) system.

In 1938 Vigoureux joined the Admiralty Scientific Service. His parting metrological shot of that era is uncharacteristic, but memorable. The international body which governs such things, the General Conference on Weights and Measures, had wanted to change the value assigned to the voltage unit against the advice of the UK experts. To the great delight of his former NPL colleagues and UK electrical engineers Vigoureux was, from his new address, able to publish a paper at that time reminding the CGPM that "it has been well said that the man with an unchangeable mind is an unchangeable ass".

He was then posted to the naval base at Portland, where he worked with colleagues on a receiver designed to improve the echo detection of U-boats. By the end of the Second World War this highly successful receiver had been installed in almost every ship of the Royal Navy.

After the war he spent a short time as Chief Scientist of the Torpedo Experimental establishment at Greenock, and in 1948 took charge of the Acoustics section of the Admiralty Research Laboratory (ARL) at Teddington in Middlesex. In 1955 he was posted to Washington as Scientific Adviser to the Admiral, British Joint Services Mission, returning to ARL near the end of 1957.

He returned to NPL early in 1958 as head of his old section, and although he ably managed a large group of metrologists until 1970, he also sustained his scientific researches. During this period he wrote a student book on electricity and magnetism, applying the gyro-magnetic ratio of the proton to measuring flux densities and monitoring the absolute value of the ampere.

Vigoureux was an excellent proof-reader and had an awesome memory. He could quickly locate a relevant equation in one of his series of meticulously written laboratory notebooks some 40 years later. He never really retired from NPL and continued to contribute to metrology in several ways including accurately computing electromagnetic fields in particular situations and writing the subsequent reports.

His many scientific lectures in later life were delivered in a measured, clear and audible style which was greatly appreciated at international meetings by his many foreign colleagues. He was bilingual in English and French. His clarity of thought and expression were reflected in his notes and translations of the proceedings of technical meetings which he had learned to produce in a very legible shorthand. Characteristically he kept careful diaries which, I understand, are written in shorthand, in German, and backwards.

He was rather short-sighted and was charmingly grateful that a cataract operation a few years ago left him able to survive without spectacles - by seeing where he was going with one eye and reading with the other. He was private, kindly, austere, well-liked and very courteous. He was a devout Catholic; early in his career he left science for a short time while he considered joining a religious order.

A perfectionist, Paul Vigoureux taught himself German and several other subjects, and was also good at Latin and Ancient Greek. It was no surprise to visit him in hospital and find him using the time to work through a physics textbook.

Joseph Evenor Paul Louis Vigoureux, metrologist: born 12 February 1903; ISO 1967; died West Molesey, Surrey 15 April 1999.