Drawing. Black ink, some wash, dimensioned and some annotations, some pencil alterations. Plan of a braced trapezoidal frame in cast iron, showing in section the parts that join it: “Plan of the lower frame & Section of the Side frames” and full-face views of two braced rectangular frames, one the back and the other a side, which was perhaps to be duplicated for the other side. Evidently there was also to be a top frame. The whole seems to have been intended as and elaborate “cage” frame for one of the copying machines. A line is drawn on, annotated: Line in which the chain or rod of the Balance might traverses”, which may provide a link to the designs for balance arrangements. Dated Apl. 1811. 30 3/8" x 22 5/8" watermark LVG, coarse laid paper.

This item is part of the contents of the workshop that Scottish engineer James Watt developed at his home, Heathfield, at Handsworth, Birmingham, from c.1795 through to his death in 1819. 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.

This drawing is one of a set made by Watt during his time in the workshop. They include detail from how to mount a diamond on the end of a wire, to designs for weighing machines, to the construction of the lathe bench present in the workshop. However, the majority concern Watt’s work on his sculpture copying machines, both resident in the workshop. They show how their design evolved over time, including details of framing, feed mechanisms, drill frames and more. These were Watt’s major project in the workshop, and provide us with dates for some of the component parts of the machines stored around the room.