[SDProf]

That scope is funny. Especially when you understand that in WW1, they used a scope like it but in reverse. Look in at the bottom, out at the top. Used from within trenches.

Like this. Not just a 'scope for viewing, but for aiming and firing from the safety of the trench..

 

[ajole]

That scope is funny. Especially when you understand that in WW1, they used a scope like it but in reverse. Look in at the bottom, out at the top. Used from within trenches.

That’s not why it’s funny.

Just saying.

 

[Rachgier]

I think they go back even earlier than the 1800's.

Nope. In 1854 a Frenchman invented the first functional periscope. Up until then they were called a polemoscope, or jealousy glass from the 1600's. They were a single barrel opera or field glass with an oblique angled lens with a spy hole in the side to let you look left, right, or down at the opera until someone got the bright idea to tip their head back to see forward over an obstruction.

I googled that shit.