Thermometer: Mercury in a Blown Bulb, Graduated in Ice and Steam (Work, 1891)

A mercury thermometer made from thermometer tubing. J. G. Lister (1891) blows a bulb on one end, draws the other end down to a hair-fine neck, fills the tube with mercury by warming and cooling it, boils out the air and seals it, then marks the freezing point in melting ice and the boiling point in steam. The mercury is heated close to its boiling point to drive out the air; its vapour is poisonous, so this blueprint is gated. Source: J. G. Lister, 'How to Make a Thermometer', Work, 6 June 1891, pp. 181-182. Picture: his Figs. 1-5.