Science — Physics/Chemistry – Easy Peasy All-in-One Homeschool Draw a diagram of the inside of a steam engine. Color where the water is blue. Color where the steam is red. Include a firebox, boiler and steam box. If you don’t remember, here’s a diagram. You can also read that page with the diagram as a reminder of how a steam engine works. Level 5-8. Watch and read about steam engines. Draw a diagram of how it works and explain it to …