His autograph signature, taken from the end of a letter: “yours sincerely, Edwd Cowper.” 2 x 8 inches, in good condition. Undated. Uncommon. Edward Cowper (1790–1852) was an English printing engineer, inventor, and academic. Cowper improved the steam printing machine, projected by William Nicholson and implemented by Friedrich Koenig. In 1816, when he described himself as an ironmonger and mechanist of Newington Butts, Cowper obtained a patent (No. 3974) for “a method of printing paper for paper-hangings and other purposes”, with curved stereotype plates fixed on cylinders for printing long rolls of paper. In 1818, styling himself as a printer, he patented (No. 4194) certain improvements in printing, which consisted of a method for a better distribution of the ink, and an improved manner of conveying the sheets from one cylinder to another. This was the origin of the “perfecting machine” which printed on both sides of the paper at once.