This engraving provides a view of the Caslon type foundry in London, England, in 1750, the year before printing came to Canada. Most of the types used in early North American printing came from this type foundry. The four men at left are in different stages of the casting process: the first is ladling type metal, an alloy of lead, antimony, and tin; the second is pouring metal into his mould; the third is swinging the mould by its bowed handle to distribute the metal within it; and the fourth is breaking his mould open to remove the cast type. In the middle, boys are breaking off the jets left by the funnel opening of the mould, and sorting the hot letters. The man in the right background is the rubber; he smooths the type against a grinding stone. The last man is the dresser, who arranges the types into straight lines, inspects them, and cuts a groove down the bottom of each row to remove irregularities, especially those caused by breaking off the jet. One of his main concerns was to ensure that all the types held the "height-to-paper" set by the depth of the mould, usually just under an inch.
In the foreground are the two sides of a mould, a complicated small machine which in the right hands could turn out 500 letters an hour. The mould is designed to take a brass matrix from which the letters are cast; it is easily adjustable for different widths of letter, but not for different sizes, as can be seen in illustration 5.
