Turn on the lights.

Exploration Stage: Crystals
From: Helen
Description: A projector needs a light source. You don't need to look at the blueprints to know that much. Can you help me find an arc lamp? It is a very powerful light source and looks like two sticks stuck in a flask.
Completed: I see you found the arc lamp! But be careful ...... don't turn it on yet. Because the arc inside will raise the temperature to thousands of degrees. Did you know? The first arc lamp was invented 77 years before Edison's light bulb came along.