[jloughry]

I recall reading something about periscope windows years ago in a book about the University of Minnesota's centre for underground buildings. It was said that looking through the periscope window from underground resembled watching a live diorama in an aquarium. I imagined something like a tilt-shift movie. Ever since reading that description, I have always wanted to see a real periscope window.

[jloughry]

Found it: it was called an ectascope and there are diagrams here:

https://www.minnpost.com/stroll/2015/09/seven-stories-down-u...

Not a very good photo of what it looked like:

http://blogimg.goo.ne.jp/user_image/6e/29/0553c64f5a894a9391...