This index card shows the formulas that the brothers used to design and test their gasoline-powered engine. To help them remember the variables, they kept a legend on the backside of the card.

After weeks of calculations, the Wrights were ready to build an engine. These images from the collection show how carefully the brothers calculated the specifications for the engine.

Front of notepage (316k)

Back of the same notepage (289k)

A small notecard (51k)

Piston calculations (299k)

Now, back to the story, as
Part I - Inventing the Future continues...