SIR JOHN FREDERICK WILLIAM HERSCHEL was born near Windsor, England, March 7th, 1792. He became one of the most celebrated astronomers of modern times, overcoming what is perhaps the greatest possible disadvantage a young man can have,—that of having a father so great that it seems at once absurd and irreverent to attempt to equal him. Yet the younger Herschel did his work so well that when the achievements of the elder are summed up, it is said, “As an explorer of the heavens he had only one rival—his son!” Besides his technical works on astronomy and physics, Sir John Herschel wrote a volume of “Familiar Letters on Scientific Subjects” (1866), which are frequently admirable in manner, as well as in matter. He died at Collingwood, England, May 11th, 1871.