A type of
lawn mower that uses a rotating
cylinder of
helical blades instead of a single flat
blade. Reel mowers (aka "push mowers") are typically human-powered instead of using
two stroke internal combustion engines. It's a pain in the ass to push them around, but it's worth it if you have a small
lawn: the US
EPA estimates that gas-powered garden equipment is responsible for 5% of domestic air pollution. The exception to the clean part is the gas-powered reel mower used on the greens of
golf courses.
The first reel mower was patented in 1830 by Edwin Budding in England. Reel mowers have the added benefit of safety - 385,000 people in the US were injured over seven years by gas mowers, while no one was reported injured by a reel mower.
Source: MIT Technology Review - http://www.techreview.com/articles/jan01/montfort.html
http://www.epa.gov/grtlakes/greenacres/wildones/wo08.htm#lawn