**Percy Daniell** was a Chilean-born English mathematician who worked in both pure and applied mathematics. He is best known for his work on integration.

- Percy spent the first six years of his life in Chile, only returning to live in Birmingham in 1895 when his parents settled back in England.
- As part of his primary school education, Percy spent a couple of years at a private school at Fladbury, Worcestershire.
- When Percy began his education there, the school was in New Street in the centre of the city.
- In 1903, halfway through Daniell's time at King Edward's School, Levett retired but his approach was very successfully carried on by his successor Charles Davison.
- Daniell excelled academically and also participated fully in school life being a school prefect and a member of the school Rugby XV.
- Lovett, himself a mathematician, wrote to J J Thomson at Cambridge asking for advice on who to appoint and Thomson recommended Daniell as an assistant professor of applied mathematics.
- Lovett approached Daniell who was very interested in the position but, since he was inexperienced in research, it was arranged that he would spend a year studying in Germany.
- Daniell was awarded a travelling fellowship and spent the period from July 1912 to October 1913 at Göttingen.
- It is highly likely that Daniell attended these (and other courses) and certainly he undertook research on a problem in the theory of relativity which Hilbert discussed in his course Theory of the Electron.
- Two weeks later, Britain was at war with Germany, but this had no direct effect on Daniell although the disruption in communications and the draft after the United States entered the war in 1917 certainly affected him, at least indirectly.
- The department that Daniell joined at Rice was small.
- Daniell was, as we noted, an assistant professor of applied mathematics and had as his only colleague Griffith Evans who was assistant professor of pure mathematics.
- Up to the time he moved to the United States Daniell had not published a single paper.
- The paper gives an abstract definition of integration now known as the Daniell integral.
- This work represents a remarkable achievement but, amazingly, Daniell also made a highly innovative contribution to a totally different area of mathematics at the same time as he was working on the Daniell integral.
- It could in fact be claimed that Daniell was at least thirty years ahead of his time, for it took that long for his major results to be rediscovered.
- another important paper of Daniell's, 'Integral Products and Probability' (1921), ...
- After this remarkable period, Daniell was promoted to full professor at the Rice Institute in 1920.
- By the time the war ended, Daniell was seriously ill and he died at the age of fifty-seven.

Born 9 January 1889, Valparaiso, Chile. Died 25 May 1946, Sheffield, England.

View full biography at MacTutor

Origin Chile

**O’Connor, John J; Robertson, Edmund F**: MacTutor History of Mathematics Archive