Grandpa Fenn's Workshop

The Windmill

Grandpa hung four big sails on a tower. He says the wind can grind grain and light a lamp. Poppy says the wind is just air.

Grandpa Fenn at the workshop door with his field notebook

Catch the wind

Pick the sails. Set the wind. Turn the mill to face it. Spin the sails fast enough to light the lamp, then fill the grain sack.

A-
B-
C-

Grandpa pours the flour into a jar and the lamp keeps glowing. The wind did all of it and never asked for a penny.

Why it works

Wind is moving air. Moving air pushes on the sails. The sails turn. The turning shaft can grind grain, pump water or light a lamp.

The mill has to face the wind. Side-on, the sails catch almost nothing. Face-on, they catch the most.

More wind means faster spin. Bigger sails catch more air, so they spin faster in the same wind.

Grandpa. Old millers turned the whole top of the mill to face the wind. Every morning. The wind does not ask what you planned.
Poppy FennPoppy checks the wind

Grandpa's notebook

Wind is moving air and it can push.

The sails must face the wind.

Bigger sails catch more wind.

Big word for the day. Energy. What it takes to make something move.

More machines are waiting on the bench.

Try the Magnet Maze

See Grandpa's Invention Wall

Back to the Chain Reaction Bench