The science of weights & measurement is the theme of "Precisely So", taking its name from the very strange 1937 Jam Handy source clip of the same name. There's a lot of stuff going on in this clip; gotta love those marching calipers and T-squares toward the end!
After assembling the original song in GarageBand, the entire 20-minute film was crunched down and compressed to fit (more or less) into the 2-and-a-half-minute song. Things seemed to fit pretty well (with a bit of chopping and fixing), so the video is pretty much the entire film, speeded way up, on top of the new soundtrack.
As usual, this is only possible through the generosity of The Prelinger Archive at archive.org/details/prelinger, which provided the free public-domain source movie.