Lantern slides and films relating to an application by E. & L. Dreyer to revoke patent 91258, 'Improvements in or relating to devices for spreading granular or powdery material'.
- part of archive:
- Papers of patent agent and engineer Sir Dugald Clerk, relating to gas engines and patent investigations
- Marks & Clerk
c. 100 slides and 3 reals of film
- Open Access