Monotype system
When the text nears the right margin, a drum on the keyboard indicates codes which are punched on the paper tape with special keys to indicate how the line is to be justified.
In 1885, the American inventor Tolbert Lanston applied for a patent on a typesetting system that included the basic Monotype keyboard, but which produced a printing surface through a cold-stamping method.
In 1897, the Lanston Monotype Corporation opened a branch in England, which later became an independent company.
During operation, two sets of keys and keybars are placed in two side-by-side trays on the keyboard.
This is achieved by placing a rectangular array of bronze matrices, each of which is 0.2 inch square, in a holder, called the matrix-case.
This was one major reason why reconfiguring the keyboard needed to be easy, since the arrangement of characters in the matrix case would be varied with the typeface.
The mould is one of the unique parts of the system, and together with the matrix-case, is the centrepiece of the caster.
Its job is to locate under the matrix to case and shape the body of the sort, and then deliver it to the typecarrier, and eventually the galley.
In the most simplistic view, the mould is a square pipe, with a conical funnel at its bottom and the selected matrix at the top.
Just for spaces, there is a second wedge with finer steps, used to set their precise width for each line, so it's "mathematically" justified.
For the casting operation, the mould width is set, and it's placed above the conical metal injector, and below the matrix.
The injector is raised, and fits into the conical funnel at the base of the mould, ensuring precise positioning.
At the same time, a pin is pressed to a round depression on the top of the selected matrix, ensuring its precise positioning and tight contact with the mould.
The metal is injected with some pressure, and almost immediately the injector and the pin retreat, releasing the mould to rush to the ejection site and back, to have its wedges adjust for the next cast, and releasing the matrix-case to position the next character to be cast.
The crossblock and the typecarrier move back, and the character is pushed inside the character-channel.
When printing tabular text, such as timetables, directories, catalogs, etc., the second wedge is not used, and the typesetter uses fixed-width spaces, called quads, such that each row begins at a fixed location.
While the set size was normally equal to the maximum character height, this was not always true: some typefaces could be somewhat wider or narrower than the standard, with many typefaces modified to be slightly wider in smaller sizes.
It is also possible to set a font slightly tighter or looser for special typographic effect.
When the right margin was approached, this information was indicated to the operator on a rotating drum on the keyboard.
As part of finishing a line of text, the operator used two rows of special keys on the keyboard to punch this information on the tape.
Of this system there have been two variants: the extra row was coded with either MNH or MNK.
[1] All the calculations are "performed" by the keyboard, and displayed on the paper drum at its top.
At the end of the line, the pointer indicates the correct settings for the wedges, which are then punched by the operator using the keys in the special rows.
