Experiment

 

During this film you'll need to take down notes and readings from the screen.

 

We are going to investigate and we shall need to be able to measure how much.

 

We shall use this machine.

 

First of all let'stake a look inside to see how it works.

 

It looks complicated but the principle is simple.

 

For this demonstration let's turn out the lights.

 

What.

 

 

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