thermometer dividing engine, iron bed with bronze and steel fittings, by R.W.Munro Ltd., London, 1925-1940
Scales upon thermometers were accurately marked using this dividing engine. Thermometers must be made to a very high quality to be accurate. The glass needs to be carefully blown so the tube width is the same along its whole length. The dividing engine then has to make precise and consistent scales on the outside of the thermometer. It was made by F. W. Johnson and Daughter of Hendon, north London.