Thursday, 29 November 2012

Making a periscope

Seeing over objects and round corners is a fascinating concept so today we made a periscope. In reality, I did most of the making as the cutting and measuring wasn't easy for the younger children. Miss Belle did the decorating and she and Middle Son have been busy looking at ceilings and over sofas.

 Two 7x7cm safety mirrors
Carton-we used a UHT milk carton but a juice carton would also be ideal. A taller narrower carton will work better than a shorter broader one.
Ruler and biro
Scrap paper and stickers for decoration

Wash out the carton carefully.
On one side of the carton, draw and then cut two parallel lines the same length as the mirrors. It is better to make these cuts too small and have to enlarge them than to make them so big that the mirrors fall through. The cuts should be at 45 degrees to the side of the carton.

On the opposite side of the carton make parallel cuts in exactly the same places. This is where the ruler is very important.

Place the mirrors in the slots. The top mirror should face down and the lower mirror should face up-the periscope won't work unless they are placed like this.

Make a large square hole just beneath the top mirror on the front side of the carton (the side at right angles to the slits for the mirrors). My square isn't square!

Make a small hole just above the lower mirror on the opposite side.

At this point the periscope will work but needs decoration.  So we set to work with paper and stickers.
 The periscope is ready for spy missions!

A periscope works by light entering by the square hole reflecting off the top mirror onto the lower mirror and then into the eye of the observer.


  1. That's REALLY creative Sarah! I love it, thanks! I remember loving periscopes when I was little. C will love this

  2. Thank you-it was fun and funny watching people looking over the edge of furniture!

  3. What a great idea, I might steal it as we are working with light in our science lessons:) Very cool looking periscope

  4. Love it! Great idea for a little spy monkey (we watch a lot of Curious George around here!)Found you through Kids Co-Op! and new follower! Hop you hop over and follow back. I would love to keep up with your blog!
    Be blessed!

  5. Thank you for commenting-just about to pop over to your blog.

  6. What a great science project! Thanks for sharing! I'm going to have to figure out where to get some safety mirrors. :-)

  7. Katie, thank you. I brought my mirrors at a sale of items from a school that had closed. When I looked on Google, safety mirror often brought up security type devices. When I Googled square shatterproof mirrors then suitable mirrors come up.

  8. This is seriously cool, you're so clever!