childhood at the Industrial Revolution: Child Labour
Gnomon1
1. How to build a proper base for the stick: a wooden box
1. In the pictures (end of document) you can see the pieces drawn to a real scale, so
glue them with a glue bar and cut them with a Stanley knife or scalpel and a steel
ruler.
2. Cut all of them.
3. Glue all the pieces together to form the box. Use some rubber bands to hold the
pieces while you are gluing them.
4. Now , you have to fix the string to the stick. The string has to be fixed 80cms
away from the floor, just on the top of the wooden stick. So, you’ll hammer a pin
through the string on the stick as you can see in the photos.
2. Wrap the string around the stick and when you get to the end, hammer another
pin into it. To check that the string doesn’t move, wrap some cello tape over it.
5. Glue the stick to one of the corners taking into account the string should be on the
outer face of it (see photo) .
Check that the stick doesn’t move while you’re gluing it to the box, so use a couple
of g-clamps.
6. Fill the box with stones or something heavy (sand, rice, ..) to prevent it from
moving.
3. How to take measurements
1. Determine solar noon for your location and time zone. (Consult your local
newspaper for the sunrise/sunset times, then calculate the midpoint) :
2. Make sure the stick is in a true vertical position. Use a carpenter's level
3. Measure the angle of the shadow of the stick while one of your mates is holding
the string firmly on the floor. The string should reach the end of the shadow and
it should be kept in tension.