Science Experiment: Periscopes

In this experiment I made a periscope out of a card board template and two pieces of a mirror.  Well, actually...my dad put it together, because it was too hard for me to make the small cuts and glue the tiny tabs.  Here's what we started with:

   
Here's the finished periscope (the mirror in the open end doesn't show because the other mirror opening is closed to the rug, and no light is coming in):

I learned that perioscopes can be used to see over obstacles and corners.  This works because light reflects out from each mirror at the same angle in comes in at.  This was sort of fun, because I got to try and find things around obstacles using the periscope.