140 Britain's Heritage of Science 



all gases could be converted into liquids. Pressure alone 

 seemed ineffective with gases like oxygen, nitrogen, and 

 hydrogen, but that might have been due to our inability to 

 apply sufficient power. Andrews, investigating the condi- 

 tions under which carbonic acid could be liquefied, and taking 

 exact measurements of the pressure required at different 

 temperatures, discovered that there was a critical temperature, 

 such that, if the gas be heated above it, no pressure, however 

 great, could convert it into a liquid. Previous experiments 

 by Cagniard de la Tour and others had foreshadowed such 

 a result, and Faraday came very near to the true solution 

 cf the problem, but this does not detract from the value of the 

 classical research by which Andrews finally established his 

 results. We have seen in our own time how, in the hands 

 of Sir James Dewar and of the Butch physicist, Kammer- 

 lingh Onnes, the subject has developed into a new branch of 

 science, enabling us to investigate the properties of bodies 

 at temperatures so low that molecular motion is almost 

 annihilated. 



The reputation of Oxford University as a centre of 

 research did not, during the last century, rest on its activity 

 in scientific pursuits; but it had among its teachers and 

 pupils at any rate one man whom any seat of learning would 

 have been proud to claim as its own. Henry John Stephen 

 Smith (1826-1889) was both a brilliant mathematician and 

 a great man. He was born in Ireland, but after his father's 

 death his mother removed to the Isle of Wight, and it was 

 there that Henry Smith received his first education. After 

 a short time spent under a private tutor, he went to Rugby, 

 where he became head boy under Dr. Tait. In spite of 

 ill-health, which for some time interrupted his studies, he 

 obtained a Balliol scholarship in 1844, the Ireland scholarship 

 in 1848, and a first-class both in the classical and mathe- 

 matical schools in 1849. In the meantime he had spent a 

 winter in Paris, where in 1847 he attended the lectures 

 of Arago and Milne Edwards. In 1861 he was elected 

 to the Savilian Professorship of Mathematics as successor 

 to Baden Powell. His researches on the theory of numbers 

 and the elliptic function placed him in the front rank of 

 mathematicians; and he showed the same perfect mastery 



