Howstuffworks.com presents clear, well-written articles for the layperson in many areas such as Earth Science, Engineering, Military and the Supernatural. In this article, written by Marshall Brain, one can learn the secrets of force-multiplying devices. For example, how a block and tackle (an arrangement of ropes and pulleys such as on a crane or sailboat rigging) works to trade force for distance. The author also discusses similar devices such as levers, gears and hydraulic pumps. This article, like other Howstuffworks articles, is easy to understand and has numerous color illustrations and animations that make learning fun. You can display a printable version of the article and sign up for a free newsletter at the site.