Returning to both Sholes and Hammond.
Sholes and Glidden didn’t use Pratt’s keyboard at first. Like most early typewriters they followed the piano model. They also used an entirely different way of getting each letter to the paper, with individual hammers bearing each letter.
Oddity: Glidden and Sholes sold their idea to gunmaker Remington, but Pratt’s idea was far more gunlike than the Sholes idea. Pratt had a hammer with a firing pin, which was pulled back then released by each keystroke.
They did copy Pratt’s two-way slide for the paper holder.
Hammond followed Pratt’s basic method of making an impression. All letters were on one sliding plate, which was curved instead of flat. There was one hammer in a single position, which struck the paper from behind.
The single plate made it easy to switch fonts. Hammond turned this into the main selling point, and the VariTyper remained popular even after digital typesetting was established. IBM turned the cylinder into a sphere in the Selectric, which minimized the motion but also restricted font size somewhat.
Polistra's Mill 