The Moulding Floor at Lane & Girvan's Caledonia Works, Bonnybridge, Falkirk
The scene is typical of the area's foundries, with its open plan floor and skylight roof supported on iron columns. The floor is covered with sand used in the moulding process.

The sand had to be riddled to rid it of lumps which would cause flaws on the surface of the casting. It is then placed in the iron mould box on the floor, which has the pattern incorporated into the top of it. A second box is then placed on this and filled with more sand, thus surrounding the pattern completely.

After tamping down, the two halves are separated and the pattern withdrawn, leaving a void in its shape. Afterwards the two halves are reunited, channels are made for pouring in the molten metal, and the mould is ready for casting.