Sound is defined and characterized as a wave consisting of oscillations in pressure of a medium. Includes graphics and links to further information.

This is a detailed biography about George Westinghouse with a link to an article about Westinghouse from the Wilmerding News, 1904. Read about his many inventions that improved railroad safety.

This resource provides a detailed discussion about how refrigerators work. Also includes a history of the invention of refrigerators, and the physics behind how they work.

This site explains the basic concepts of pneumatics, which is often used in manufacturing.