This project took a year to finish, not because of the size of the collection or my available time, but because I couldn’t easily estimate the number of slides or the amount of supplies needed. Reordering archival materials, and waiting on them, took almost as much time as the actual cleaning and scanning did! Lesson learned.
This collection has a total of 193 slides. The vast majority show the German and Austro-Hungarian forces, with some quotidian scenes from Eastern Europe as well. Many are from Underwood & Underwood, and all of them appear to have duplicated for use in newspapers and magic lantern shows.
Thanks to everyone who has commented, emailed and otherwise helped me find additional information on the slides and the scenes they depict.