The English physicist John William Strutt, 3d Baron Rayleigh (1842-1919), was one of the last of the great individual classical physicists whose interests spanned all disciplines.

John William Strutt was born in Maldon, Essex, on Nov. 12, 1842, the eldest son of the 2d Baron Rayleigh, a prosperous Essex farmer and landowner. His talent in mathematics was recognized early, and in 1861 he entered Trinity College, Cambridge. Under the tutelage of a great teacher, E. J. Routh, he captured in 1865 the coveted position of senior wrangler and also won the Smith's Prize. At Terling Place, the family seat in Essex, he converted the stables into a laboratory. There he commenced experimental studies in photography, optics, electricity, and acoustics, working alone for the next 50 years. He remained active in his laboratory until a few days before his death on June 30, 1919.

In 1870 Strutt derived theoretically, and verified experimentally, the mechanism of the scattering...