Balfour Stezuart. 253 



Memoir of the late Professor Balfour Stewart, LL.D., 

 F.R.S. By Professor A. Schuster, Ph.D., F.R.S., 

 F.R.A.S. 



{Received April 2j, 1888). 



Balfour Stewart was born on November ist, 1828. He 

 went to school at Dundee, but entered St. Andrews 

 University at the age of thirteen, and from there passed on 

 to Edinburgh, where he studied under Professor Forbes. 

 Leaving College when he was eighteen years old he was 

 sent by his parents to serve his apprenticeship in business 

 with a firm at Leith,and afterwards went out to Australia with 

 a cousin, James Balfour, to start on a commercial career. But 

 he was never fond of business and soon returned home to 

 Edinburgh, where he became assistant to Prof Forbes in 

 1853. In 1859 he was appointed Director of the Kew 

 Observatory, and held this post until 1870, when he was 

 appointed Professor of Physics at the Owens College, 

 Manchester. He died of apoplexy, on December 19th, 1887, 

 at Ballymagarvey, near Drogheda, where he had gone to 

 spend the Christmas holidays. 



Balfour Stewart's name was first prominently brought 

 before the public by his researches on Radiant Heat. His 

 paper was presented to the Royal Society of Edinburgh, 

 and read on March loth, 1858. 



Stewart's claim, as one of the founders of the theoretical 

 basis of spectrum analysis, rests on the experiments and 

 reasoning contained in this paper. To appreciate the work 

 done by Stewart we must realise what was known and 

 generally recognised at the time his experiments were made. 

 Those interested in the subject will find an account of the 

 early history of Prevost's theory of exchanges by Stewart 



