Simmance S.G. bell. Bell type gas holder capacity approx. 1 1/2 litres with calibrated outlet orifice. The measured flow-rate permits calculation of the density of the gas contained. Simmance S.G. bell, Bell type gas holder
Maker's plate from No.18 gas holder at Great Harwood Gasworks, by Robert Dempster & Sons Ltd, Blackburn, 1953-4 Maker's plate from No.18 gas holder at Great Harwood Gasworks 1953