Autograph Letter Signed, to “My dear Puckle” about the opinion on Puckle’s book expressed by Mathematical Tutors at Cambridge, commenting (with mathematical symbols) on his “analytical theory of conic sections”. 4 pp. 7 x 4 inches, in good condition. The Vicarage, Chesterton, Cambridge, 22 March 1868. William Walton of Trinity, Cambridge, author of On The Differential Calculus (Cambridge, 1846).