1 Face plate 9” dia. with 2½” brass centre
This item is part of the contents of the workshop that Scottish engineer James Watt developed at his home, Heathfield, at Handsworth, Birmingham. Although Watt is best known for his work on the steam engine, his workshop contains a wide variety of objects from many different projects, from chemistry to sculpture-copying.
The description of the item was written by Edward Collins, the land agent responsible for Heathfield when the workshop was given to the Science Museum in 1924. Collins could not always identify what he was looking at, but always described what he saw clearly. This has allowed his descriptions to form the basis of subsequent research.
This item and the next correspond to drawings by Watt of parts intended for his sculpture-copying machines, both of which remain in the workshop. They appear to be a pair of chucks, serving to hold pattern and workpiece while allowing them to be turned through corresponding angles. That they form a pair of different size suggests strongly that they were meant for the reducing machine. However, they cannot be fitted to it as it now is, and probably they were superseded by the present, or some intermediate, arrangement.