Regulator valve with wooden mounting board from steam engine.

1790-1819 in Birmingham
James Watt

Regulator valve consisting of brass tube and sliding cap with wooden cylinder and mounting board, intended for use on a steam engine. Taken from the contents of the private workshop of James Watt from his house of Heathfield, Birmingham, where he lived from 1790 to his death in 1819.

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 regulator or steam valve was most likely made for Watt’s experimental engine, built over the Winter of 1763-1764, and utilising a wooden cylinder. The brass steam pipe is insulated with a wooden bush which is slightly tapered, and would have been fitted into the bottom of the engine’s cylinder in line with standard practice at the time. The regulator would have been opened and closed with a spanner. This has been removed, though it is possible that it survives un-identified elsewhere in the workshop. However, the square end and nut it would have attached to can be seen on the end of the regulator stem. The fragment of wood the regulator is attached to is a part of the boiler which would have raised steam to feed the engine cylinder.


James Watt's Garret Workshop
Object Number:
brass (copper, zinc alloy), complete and wood (unidentified)
overall (estimated): 100 mm x 120 mm x 100 mm, .435kg
Major J.M. Gibson-Watt