Experimental equipment to test electrical conductivity in a vacuum mb-code 584DA with figures and cart in

with figures and cart in foreground

St Saviour's Churchyard

The sitter's right hand can be seen holding a paper

'First Stage of Cruelty'

one standing on a heavy carved wooden table

Experimental equipment to test electrical conductivity in a vacuum mb-code 584DA with figures and cart inPlate 9 figures 1 2 from the paper 'Electrical experiments made in order to ascertain the non conducting power of a perfect vacuum', by William Morgan, Philosophical Transactions of the Royal Society, vol. 75 (1785), pp. 272 278. Figure 1 shows a 15 inch mercury gauge partially coated with tin foil, emptied of air and inverted into a mercury cistern. A wire is visible within this reservoir, through which an electrical current was passed but without