This observation was the first step in the process of electroplating, which is electrotyping when applied to the art of typography.
In 1837, thirty-eight years after Volta’s discovery, Mr. Thomas Spencer of Liverpool, England, accidentally stumbled upon the first realization of the electrotyping process.
While experimenting with a modification of a Daniell battery, he used an English copper penny as one of the poles instead of a plain piece of copper. A deposition of copper from the solution in the battery took place upon the penny, and upon removing the wire which attached the penny to the zinc plate a portion of the copper deposit was pulled off the penny also.
This first copper electrotype shell Spencer found to be an exact duplicate or mold of part of the head and lettering on the coin. It was as smooth and as sharp as the original.
It was some time later, however, before this suggested to him any useful application of the process. Another accident made him appreciate the full value of his discovery. This time he carelessly dropped some varnish on a strip of copper which he was going to use in the same way he did the penny. Upon removing the copper from the battery he observed that there was no deposition of copper on those parts of the strip where the varnish had dropped.
Spencer then conceived the idea of applying this principle to the arts by coating a piece of copper with varnish or wax and engraving a design in the coating, thus exposing the copper strip in the engraved lines. He did this, and then deposited copper in the design so engraved. Upon removing the coating the design was exposed in relief on the piece of copper.
On September 13, 1839, Spencer read a paper before the Polytechnic Institution of Liverpool, which he accompanied with specimens of both electrotypes made by this process and of printing from these electrotypes. The publication of this paper acted like an electric shock upon society.
Developing his process, Spencer first used lead as the plastic medium in which to mold printing surfaces, and it is to be noted in this connection that in doing so he anticipated Dr. Albert’s lead mold by considerably over three quarters of a century. Spencer impressed a form of type on a planed piece of sheet-lead and subjected both of them to the action of a screw-press. A perfectly sharp mold of the type form was thus made in the lead. This lead mold was placed in a battery, and at the end of eight days a copper shell one eighth of an inch in thickness had been deposited.
It was then removed from the apparatus and the rough edge of the deposited copper filed off. Being subjected to heat, the copper shell loosened from the lead-mold. Spencer called this a “copper stereotype.”