Gas chamber Gas chamber A gas chamber is an apparatus for killing humans or other animals with gas, consisting of a sealed chamber into which a poisonous or asphyxiant gas is introduced. The most commonly used poisonous agent is hydrogen cyanide; carbon dioxide and carbon monoxide have also been used. Gas chambers were used as a method of execution for condemned prisoners in the United States beginning in the 1920s and continue to be a legal execution method in three states. During the Holocaust, large-scale gas chambers designed for mass killing were used by Nazi Germany as part of their genocide program.
Lawn mower are still available. The reel is attached to the mower's wheels by gears, so that when the mower is pushed forward, the reel spins several times faster than the plastic or rubber-tired wheels turn. These types of reel mowers offer the benefit of zero pollution being produced. Since all of the energy necessary comes from the user, however, this method of mowing is the most strenuous and is not recommended for large lawns. Depending on the placement of the reel, these mowers often cannot cut grass very close to lawn obstacles, like trees, driveways, edging, etc., and also require a