Introduction: PVC Periscope

My son came to me with an idea to build a periscope. He had found a simple project in a book which used a milk carton and two mirrors. We had a couple of mirrors, but no milk carton. So, the Dad said: "We are not going to build this toy periscope, we are going to build a real one!". 
I bought a couple of 3" PVC elbows ($2.39 ea., and a 2-ft. PVC pipe ($5.44,
I had already a couple of 3" square mirrors from Michaels (sorry, no link here).
Then I cut two slots in each PVC elbow using Dremel Multipurpose Bit 561 (good for plastic and wood). 
The rest was easy: adjust the mirrors so they are at 45 degrees and make sure you see through the periscope. Then fix the mirrors using a glue gun.
The periscope is ready!