Gas chamber carbon monoxide as the lethal agent. Sometimes a box filled with anesthetic gas is used to anesthetize small animals for surgery or euthanasia. 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
Internal combustion engine to start it turning. Two-wheeled vehicles may have their engines started in one of four ways: There are also starters where a spring is compressed by a crank motion and then used to start an engine. Some small engines use a pull-rope mechanism called "recoil starting," as the rope rewinds itself after it has been pulled out to start the engine. This method is commonly used in pushed lawn mowers and other settings where only a small amount of torque is needed to turn an engine over. Turbine engines are frequently started by an electric motor or by compressed air.