After the type is set into a form, suitable for ordinary printing, the electrotype process begins by smashing the form into a thin layer of wax on a metal plate. The metal plate will become the negative electrode in the plating vat.
The form is placed face down on the wax layer forming a sandwich.
A hand moulding press is just a big scissors jack, smashing the form into the wax with considerable pressure. Heavy pressure wouldn’t really be needed for this card-size form, but when the form was big enough to print a newspaper, the PSI totalled up to many tons.
After the pressing, the form is taken off, leaving the female impression in the wax.
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Next, hand editing was usually needed. Wax editors acquired a fine sense of temperature and surface examination. The wax table controlled surface temperature by letting in more steam from the kettle or more cold water. The kettle kept a supply of molten wax, and the wax editor used an iron similar to a soldering iron to add or subtract wax from the surface. The surface needed to be exactly flat, and all the crevices needed to be precise and sharp.
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The next stage applied a fine layer of sticky graphite to the surface of the wax. The graphite acted as one conductor in the vat, attracting copper atoms to the surface and also allowing the copper to separate when done. Graphite was usually called black lead (a name that persisted in pencil graphite) and the machines to apply graphite were called blackleading machines. This one is a wet blackleader, spraying a solution of water and graphite onto the surface, scanning the wax back and forth with the spray head always facing forward to insure that the crevices are filled. Dry blackleading machines were more complex, with an orchestrated series of active brushes something like a modern Roomba. Wet machines were preferred because the dry machines sometimes scratched the wax.
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Now into the vat, where a dynamo supplies low voltage and high current to send copper atoms voyaging from a copper anode into the graphite cathode.
Plates of different sizes required different currents, so the current was controlled by a switchable set of low-ohms resistors. The resistors ranged from smaller gauge (less flow) on the left to larger gauge on the right. Several of them could be paralleled for higher current. This switch set presaged a modern digital-to-analog converter, where various combinations of bits let varying currents pass to the speaker.
The actual plating is the same as I described before in the miniature setup, except larger and faster. The charge pulls atoms from the copper anode, and they migrate to the negatively charged graphite surface, forming a copper surface with even thickness.
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Finally we put ink on paper. I’ve animated several simple flat presses, so it was time to do a cylinder.
Fast printing has favored cylindrical forms for 150 years. Hot lead, whether individual letters or Ludlow and Linotype slugs, is hard to curve and easy to throw out centrifugally. Wedge systems were developed, but they were less effective than a single curved plate. The electrotype plate won the battle for cylindrical printing, making the extra stages worth the expense.
This is a VERY simple cylindrical press, invented by JR Willbur of Cleveland in 1867. Nicely inside Kellogg’s time and place. It was meant for cards or envelopes, not newspapers or books. I don’t think it was ever used seriously because Willbur didn’t provide an easy way to insert and remove each card.
In this closeup view you can see the plate curved around the main cylinder. Here we finally get back to the metaphor of electrotype as boilerplate, which is where I started on this subject!
The platen is the cylinder below the main. Ink comes from the topmost cylinder, which is hollow and perforated. The top cylinder rolls ink onto the black belt or ribbon, which constantly inks the plate. I’ve added the yellow belt below, to carry the printed cards out. A similar belt or ‘grabber’ roller would be needed on the front for fully automatic operation.
Animating it with the right side hidden:
Willbur seems to have been aiming for postal applications. This detail of the press patent shows how a postmark with an odometer-style date could be incorporated in the main cylinder. The postmark is Cleveland.
Another patent was a rotary hand stamp for similar purposes. Note the specific name and address in his seal:
Tibbitts was a witness on the patent. I’d guess Willbur worked for Tibbitts. The address on Superior is now a parking structure.
Polistra's Mill 