Part of Snifting Valve from large steam engine.

1763-1764 in Birmingham
James Watt

Part of snifting valve consisting of brass elbow with flange and wooden fixtures, intended for use on a large 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 (see note)

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 is a brass snifting valve for a large model engine, built by James Watt over the winter of 1763-1764. The body has been bored and partly turned, then finished by filing. Two stout pins are screwed firmly into holes drilled and tapped in the side of the valve body, and these are cross-drilled to form a guide for a spindle on the valve plate. A bent finger of brass is fixed to the valve body by a cheese-head screw tapped into the side of the valve body, to prevent the valve plate from falling out. There are two iron woodscrews stuck in holes drilled through the flange that should fit against the cylinder wall. These, and the presence of putty, indicate that the cylinder wall was made of, or was covered with, wood.


James Watt's Garret Workshop
Object Number:
brass (copper, zinc alloy) and wood (unidentified)
Major J.M. Gibson-Watt