How to Make a Play Telescope

Making a telescope for play is very simple. At its most basic level, all you would need for a play telescope is a cardboard tube that you could look into and pretend to see things in. However, you might be surprised to learn that making a toy telescope at home that actually works requires only slightly more effort than looking through a pretend telescope, and it is a good way to have fun with your kids and teach them how science works.

Difficulty: Moderately Easy

Instructions

Things You'll Need:

• 2 magnifying glasses, one big and one small
• Measuring tape
• Newspaper
• 1 sturdy cardboard tube
• Scissors
• Duct tape

1. Focus the two magnifying glasses. Place the small magnifying glass near your eye. Meanwhile, move the larger, objective magnifying glass back and forth between the smaller magnifying glass and the newspaper until the newspaper print comes into focus in your smaller eyepiece.

2. Have a friend measure the distance between the two magnifying glasses. This is the focal length. The tube you use to build your telescope should be at least as long as the focal length.

3. Cut a slot in the tube for each magnifying glass. Cut a slot for the big magnifying glass a couple of inches from the end of the tube. Insert the bigger, objective magnifying glass and tape in place with duct tape. Then, measure the focal distance on the tube and cut a second, smaller slot for your eyepiece. Insert the smaller magnifying glass and tape that in place also. If you have any excess tube at the eyepiece, cut it away so that the eyepiece is only about 1 inch from the end of the tube. If done correctly, when you look through the eyepiece, the image you see should be in focus.