Photogenic drawing negative by William Henry Fox Talbot (1800-1877). Talbot invented the negative/positive process for producing photographs between 1835 and 1839. For the first time any number of prints could be made from a single image, from the negative. This is known as the calotype process. In 1839 Talbot engineered to ensure his name was given to pioneering photographic developments, holding exhibitions to display his scientific advances. Included were images such as this.
© National Museum of Science & Media / Science & Society Picture Library