Experimental equipment to test electrical conductivity in a vacuum mb-height 4477 The Queen (centre) seen here

The Queen (centre) seen here with Princess Margaret

North front of Princess's Theatre on Eastcastle Street

South elevation of the old St Paul's Cathedral

Formal photographic portrait of Thomas Lauder Brunton

Sir George Grey

Experimental equipment to test electrical conductivity in a vacuum mb-height 4477 The Queen (centre) seen herePlate 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