Between 1774 and 1792 Rooker gave his address as 'opposite the Museum, Great Russell Street, Bloomsbury', where he was a neighbour of Benjamin Wilson (they had both previously lived in Great Queen Street).
The present drawing is a 'unique record of a remarkable occasion' (Conner, op.cit., p. 97).
The experiment depicted in the present drawing was conducted by Benjamin Wilson, portrait painter, in his capacity as scientist. Before Fellows of the Royal Society and members of the Board of Ordinance, he operated his great cylinder to stimulate the effects of a thunderstorm and was to conduct fifty experiments with it.
This series of experiments took place after a storm in May 1777 in which the gunpowder magazine at Purfleet was struck, despite being fitted with pointed conductors. Wilson believed that pointed conductors were largely ineffectual and with the support of King George III he set out to prove that round-headed conductors were more efficent. Wilson produced a paper for the Royal Society and the present drawing was engraved as frontispiece.
The Pantheon was built by James Wyatt, and opened as Assembly Rooms in 1772. It was used for concerts, theatrical events and special exhibitions and in 1784 Lunardi exhibited his balloon there. It became the King's Theatre in 1791 and was destroyed by fire on 14 January 1792, and the ruins were subsequently sketched by William Marlow and J.M.W. Turner.