Is this an encryption device, how was it used, how does it work? [American Civil War]

by Bokehlicious

So, I've been watching the mildy entertaining show Turn. It is about spying, secret messaging etc. during the American Civil War. In the intro scene there are several inventions depicted which were used to covertly pass on information. This caught my attention.

So my questions are:

  • What is it?
  • What was it used for? (encryption?, copying a letter?)
  • Was it really used and if so what influence on the war did it have?
ididonce

That looks like a pantograph. In this case, it was probably being used for miniaturization: to write a really tiny message that would be easy to hide.

itsallfolklore

For the record, it is probably important to point out the AMC show "Turn" is about the American Revolution (not the Civil War).