Caught Mapping is a nine-minute film, made in 1940, about how the road maps of the time were made — and, more importantly, revised, with a fair bit on field surveyors. I was surprised that the film reported that map revisions could be made every few weeks — a far cry from the annually issued road maps I grew up with. The film is public domain and can be downloaded or streamed in several formats. (My significant other, Jennifer, wants the Mystery Science Theater 3000 version, or at least wants there to be one.) Via Cartography (from whom I steal too much, but Paul finds stuff too good to ignore — I can’t help myself).