The River from 1937 about the Mississippi, 15 mins:
And a middle 2.5 minutes here. Apparently the ending is missing.
This evening I've been perusing some of the old films at the Internet Archive. It's neat to see stuff like mechanical engineering careers at DuPont or the full clip of the nuclear bomb test, the one where the houses get blown away, in color, or even the Tacoma Narrows newsreel.
There's also something kind of strange about watching old films. It's more than smugly knowing, depending on the year it was made, that most of the people in it, certainly the adults, are long dead.
Perhaps it's the thought that even before the end of my generation's lifetime, people who won't be born for decades will watch videos from this and the last decade, in which all of my experiences so far are contained, and it will look as primitive and out of style as these do to us. It puts into perspective how humanity is an unbroken, endless precession and we just happen to be the ones passing in front of the present booth at the parade right now.
One of the most unsettling ones I've seen is Berlin: Symphony of a City. (I can't find a version with its accompanying music to link to, but here's the beginning silently.) While it's fascinating to see what a go-go place and how strikingly modern Berlin was in 1929, it's uncomfortable to realize how just like us they were--families, commutes, work, factories, shops, newspapers and coffee, having fun--knowing what would happen there over the next 16 years.