The Knights of the Round Table would have appreciated this periscope to look over walls or around corners as an invaluable secret weapon when defending their castles.
It is advisable to buy your mirrors before starting any woodwork in case you can’t obtain the exact size that I have used. I found that small mirror tiles were ideal for the job. Within reason, the tube can be as long as you like.
1. Your first job. once you have chosen your mirrors, is to cut out the two corner blocks on which they must be mounted.
Take a length of timber, the thickness of the mirror’s width, and mark out two right-angled triangles (see plans) on the side face making sure that the length of the diagonal is the same as the length of the mirrors. It helps if the timber is longer than you actually need for the two blocks in order to give you some ‘elbow room’.
Fix one end of the timber firmly in a vice and, using a tenon saw. cut off the corner blocks. Remove saw cuts and double check that the mirrors fit on the diagonal faces.
2. Cut out the back and front of the periscope ‘tube’ from plywood. Glue the corner blocks on in the correct position (see plans).
3. Cut out the top and bottom of the ‘tube’ and glue and panel pin these in place.
4. Now glue your mirrors in position (you can use self-adhesive pads, if you like). When the glue has dried, glue and panel pin the sides on to form the tube. You will need to be fairly gentle at this stage to avoid cracking the mirrors.
5. To prolong the toy’s life I would advise spending some time explaining to your children how the periscope works, and that the mirrors will break if it is dropped or roughly handled. Do be sure they understand that if a breakage does occur, they should call an adult to clear up the pieces of mirror rather than try to pick them up themselves. It might even be a good idea to fit handles on the tube for extra safety.
Side 2 off 552 × 108 × 9mm (2l ¾ ×4 ¼ × 3/8in) Plywood
Front and rear 2 off 476 × 108 × 9mm (18 ¾ ×4 ¼ × 3/8in) Plywood
Top and bottom 2 off 152 × 127 × 9mm (6 × 5 × 3/8in) Plywood
Corner block 2 off 108 × 76 × 76mm (4 ¼ × 3 × 3in) Timber
2 off 108mm (4 ¼ in) mirror wall tiles