But Edison's work on the automatic did not stop with this basic suggestion, for he took up and perfected the mechanical construction of the instruments, as well as the perforators, and also suggested numerous electrosensitive chemicals for the receivers, so that the automatic telegraph, almost entirely by reason of his individual work, was placed on a plane of commercial practicability.
"Edison, His Life and Inventions"
Frank Lewis Dyer and Thomas Commerford Martin
April 22, 1873 151,209 Automatic Telegraphy and perforators Therefor .
"Edison, His Life and Inventions"
Frank Lewis Dyer and Thomas Commerford Martin
Knives, arrow-points and perforators of chipped stone are found in all parts of the continent.
"Marvels of Modern Science"
Paul Severing