Joseph Sloper, English inventor, 1873.
© Science Museum / Science & Society Picture Library
Studio portrait by The Photographic Co Ltd of Joseph Sloper (1813-1890), builder and decorator, and inventor of the perforation proces. His perforating machine could be used for perforating initials etc. on postage stamps, bankers' cheques, and other valuable documents, thus preventing fraud. He was granted a patent for his device in 1858 and many firms began using the perforating machine for checks. In 1882, Sloper's perforating machine replaced underprinting as the Post Office's approved method for protection against the theft of stamps.