It is well known that Devant tried to sell seats in Maskelyne’s Grand Stand at St. Paul’s for the Queen’s Diamond Jubilee procession on 22 June 1897, for example, see Ref. no. N2082. However, this is the only evidence that I have seen for Devant selling seats in the Royal Horse Guards Pavilion in Whitehall, a completely different part of London. The Magic Circle Archive also has a copy of this advertisement.