Proctor joined the
British Museum on 16 October 1893 as an assistant in the Department of Printed Books. He quickly became an expert on early typography and began describing every known European type
fount used before 1520. Proctor rearranged all of the incunabula in the British Museum geographically by place of printing in what is known today as "Proctor order" and he compiled
An Index to the Early Printed Books in the British Museum: From the Invention of Printing to the Year 1500 which was issued in four parts from 1898 to 1903. ==Death==