Drawing. Arranged along one long edge: “Scheme for diminishing machine with triangular rod / the Sockets sliding by proportional screws / Jany 19th 1809”. 5 views in black ink; and along the other long edge (the sheet turned around): “Scheme for diminishing machine with double tubes / the Sockets sliding by proportional screws / Jany 20th 1809”. 4 views in black ink, and a further unfinished drawing in pencil, probably related to these. Annotated in black ink: “abandoned for difficulty of execution”. Endorsed by J.W. on reverse in black ink: “Sliding Sockets 1809”. 21 ¾" x 17 3/8", watermark J WHATMAN / 1805.

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.