I decided last summer, before I started this blog, that we would try and make a periscope, thinking that it would be a fun toy for a little boy who liked looking out of windows but wasn't tall enough without standing on something. The small boy was keen to make a periscope, despite not knowing what it was, so we got off to a good start, but it wasn't until the Covid-19 lockdown that the finished periscope was in any way a success!

I had already designed a cardboard net (i.e. the shapes we needed) for the pieces as he had (and still has!) very limited patience for any cutting and sticking activities so I didn't think it'd keep his interest until it was made if we started from scratch.  I cut three pieces from two cereal boxes.  The first was the net for a long square tube with two viewing holes on opposite sides (see picture) which was around 25cm long.  Each side of the square was 5cm, which was the width of the original cereal box. The other two pieces were identical, and designed to place each mirror at a 45 degree angle so that the image is reflected from one window in the periscope to the other.  I also cut two pieces of sticky-backed mirror to fit these (7.1 x 5cm).  A picture of the flat pieces is below.

Nets for the periscope pieces

The finished periscope worked in the sense that an image was visible, but it was very distorted and the periscope wasn't really very useable. This is because the sticky-backed mirror was quite uneven and therefore the reflection is imperfect. When you have two such mirrors, the end result is really quite disappointing and it's difficult to work out what you are looking at. The small boy enjoyed looking at Alphablocks letters which were near one window and seeing their image by looking through the other window then telling me which letter he could see, but it wasn't really good enough to have fun looking round and over things which I had hoped it would be. 

Image of a pear on our tree seen through the periscope

The idea had potential, and the boy was still interested, so I decided to see whether I could get some inexpensive shatter proof mirror. I bought a few pieces including a couple of 5cm squares which we can reuse in other projects (these are the right width but not long enough to be ideal), and they took a week or two to arrive. I took the periscope apart and stuck them over the sticky backed mirror then glued and taped it back together. Not a perfect design, but it was a huge improvement with a crystal clear image.

The squashed periscope has seen better days but it still works!

I thought we'd made a good toy with the improved mirrors, but the boy sadly wasn't interested at the time, even when I tried to demonstrate how we could see out of the window from his height - he insisted on fetching a stool instead! I think he was probably put off by it not working very well to start with, and didn't really understand that I'd improved it. 

I put the periscope on one side intact and it lay forgotten about for months. When the now 3 year old was bored recently, I found it and gave it to him. He remembered it was a periscope and had a look through it. He was quite taken with it and has wandered around using it every few days. His favourite activity is lining it up with his brother's face sideways so they can see each other which wasn't what I had in mind, but is quite amusing. It's now suffering the ill effects of having been sat on by a toddler and dropped repeatedly by the 3 year old, and is starting to fall apart. I think given his enthusiasm we will have another go at making one soon!