Autograph Letter Signed, to Mr. Cooke, inviting him to dine at the Royal Astronomical Society Club. 1½ pages 7 x 4½ inches, fine. Croydon, 6 November 1899. James Whitbread Lee Glaisher (1848-1928) son of James Glaisher, the meteorologist, was a prolific English mathematician and astronomer. Influential in his time on teaching at the University of Cambridge, he is now remembered mostly for work in number theory that anticipated later interest in the detailed properties of modular forms. He published widely over other fields of mathematics. He was the editor-in-chief of Messenger of Mathematics. He was also the tutor of the philosopher Ludwig Wittgenstein. He was president of the Royal Astronomical Society 1886-1888 and 1901-1903.