This is a vintage glass lantern slide of a river in Florida, circa 1930. While posting to another blog I curate, it struck me how much these slides can look like paintings, including the rowboat image below.

Produced to be viewed with a projector, lantern slides were both popular home entertainment and an accompaniment to speakers on the lecture circuit. They reached their popularity about 1900, but continued to be widely used until the 1930s when they were gradually replaced by the more convenient 35-mm slides- more here 

You can see all the vintage Florida lantern slides here.