I spent the last two years of my apprenticeship getting to grips with the Monotype keyboard, enabling me, eventually, to touch-type. The Monotype keyboard was pneumatic machine which punched a wide paper tape, making the calculations for justifying each line of type. The spool was then put on the caster where it would read the last punch first and set itself, ready to cast each line of type.
The keyboard was made of heavy cast iron with 7 keyboards (roman upper case, roman lower case, italic upper case, italic lower case, bold upper case, bold lower case and small caps). By depressing a key the paper tape would be punched and a pointer rise up a spinning ready-reckoner drum which would indicate the combination of keys to be pressed for the justification setting. When the job was finished the spool would be taken to the Casting Room where it would be placed on a caster. The caster would read the tape, last perforation first, set its word spacing, and position the matrix case over the metal injector to receive the hot metal and push the type character by character, line by line out of the side and onto a galley.
Both machine rooms were noisey places, the Casting Room being particularly hot.
For a large general jobbing printer, like Qualitex, the Monotype system held distinct advantages over the Linotype/Intertype systems. Individual characters could be replaced so that a job would not need to return for a complete line to be reset, although one disadvantage was that a galley of Monotype was quite a bit more unstable and many a galley found its way onto the floor, especially if it was incorrectly spaced and then "locked" into a chase.
As Qualitex became more and more litho orientated the need for hot metal diminished and the Keyboard Room shrank from some 14 machines to a couple, which were moved to the loft. By the early eighties hot metal Monotype became obsolete and in 1987 all production of new hotmetal keyboards and casters ceased. A quick demise for a typesetting system that had not changed significantly since its invention towards the end of the nineteenth century.