One letter to James Dinwiddie from D Burges
One letter to James Dinwiddie from Dr Blacklock
One letter to James Dinwiddie from Dudley Adams
One letter to James Dinwiddie from Ian Wood
Optics
Optics, No. 1-3
Plane Mirrors; Archimedes; Gravity
Two letters to James Dinwiddie from William Mackintosh Esq.