Sheet 3 - Frames 1-1a thru 7-7a--Mary Purchase with students, working in lab on demonstration of electricity consumption; Frames 8-21--Same as Sheet 2, Sept. 1977

Sheet 3 - Frames 1-1a thru 7-7a--Mary Purchase with students, working in lab on demonstration of electricity consumption; Frames 8-21--Same as Sheet 2, Sept. 1977, Job #539, Box: 16. Cornell University Media Services Photo Section records, 21-37-2227. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/164381 Accessed October 23, 2025.