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 lifting air-cushion is destroyed by wide gaps between the chassis and the ground. Hover mowers are built to operate on steep slopes, waterfronts, and high-weeded areas, so they are often used by golf course greenskeepers and commercial landscapers. Grass collection is often available, but can be poor in some models. The quality of cut can be inferior if the grass is pushed away from the blade by the cushion of air. A robotic mower is contained by a border wire around the lawn that defines the area to be mowed. The robot uses this wire to locate the boundary of