"Most Common Photographic Types of the Century" ~ Nearly all consumer photographs in the were produced by one of these technologies. By recognizing the photographic format, you can more easily date the photo and your ancestor.
barnardo children - Google Search
British Home Children - example record - Left side
Beware… Drink only approved water. Never give a germ a break! War Department, United States, A soldier, about to drink from a microbe-infested jungle stream, is surprised to see in the reflection his face transformed into a figure of death.