‘Humphreys’ electromagnetic demagnetising machine, Plant no. 686. Made by J. H. Humphreys & Sons Ltd., Oldham, Lancashire, England, 1916, and customised by The Monotype Corporation. Used to demagnetise work-pieces, part of the equipment used in the production of Monotype matrices.

This machine is one of many used in the process to make a 0.2-inch (0.51cm) or 0.4-inch (1.02cm) matrix.

There were 82 separate processes needed to transform a designer’s drawing of a letter, figure, punctuation or symbol into a piece of Monotype metal type for printing. A pantograph was used to trace and cut the letter from a copper pattern into a piece of steel called a punch. After being hardened, the punch was driven into a piece of bronze using a crank press to produce a matrix. The finished matrix was ready to go to the Monotype Composition Caster where molten metal was pumped through a mould against the matrix to produce a piece of type.