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