Comprises 36 volumes of reports on patent actions and other matters by Dugald Clerk (and also by Marks & Clerk and M. Atkinson Adam), 10 volumes of reports on searches and cases for opinion of counsel by Marks & Clerk and 3 volumes of reports on patent actions and other matters by M. Atkinson Adam. Also contains notebooks, letters patent, patent specifications, photographs, drawings and trade literature relating mainly to Clerk's work on gas engines and 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'.