43 colour plastic-mounted and 7 black and white glass slides used by G. H. D. Mackie for his lecture "Activities in British Railway Workshops - Shildon Works" of April 1964 (for a copy of the script see 2004-7908). The slides illustrate the British Railways network, Shildon's place within the network, the layout of the works, interior views of the workshops, various repair and construction processes, "before and after" pictures of wagons requiring repair, examples of wagons constructed at Shildon, "Operation Face-Lift" to improve the works, etc. The lecture was probably written in conjunction with Mr. Mackie's larger report "Impressions of British Railway Workshops" (2004-7907). At the time he wrote the lecture, Mr. Mackie appears to have been working at Inverurie Workshops.