Autograph Letter Signed, to E.W.Cooke R.A., explaining that pressure of business prevents him calling to “have a quick look at your Pictures for the Royal Academy”, resting content to see them at the Academy. A good one page example, 7 x 4 inches. 1 Delahay Street, 9 April 1868. Sir Charles Hutton Gregory (1817-1898), civil engineer. Gregory was consulting engineer of several major railway construction works, including those in Ceylon, Trinidad, Cape Colony, Perak and Selangor. He was the first to use railway semaphore signalling which he employed on the London and Croydon and the South Eastern Railways in 1842-3. This method later superseded all others and was dominant from 1870.