Autograph Letter Signed, re-arranging a meeting. A good one page example, 6 x 4 inches. Undated. William Hopkins FRS (1793–1866), mathematician and geologist. He made important contributions in asserting a solid, rather than fluid, interior for the Earth and explaining many geological phenomena in terms of his model. He wrote also on the motion of glaciers. He played first-class cricket from 1825 to 1828. He was mainly associated with Cambridge University Cricket Club and made 4 known appearances in first-class matches.