
Simple Machines (Let’s Read-‐and-‐Find-‐Out Science series)
D. J. Ward
Learn about the six basic simple machines—levers, wheels and axels, pulleys, ramps, wedges, and screws. Pen, ink, and digital illustrations.

D. J. Ward
Learn about the six basic simple machines—levers, wheels and axels, pulleys, ramps, wedges, and screws. Pen, ink, and digital illustrations.