Atmosphere of Earth Atmosphere of Earth The atmosphere of Earth is the layer of gases, commonly known as air, that surrounds the planet Earth and is retained by Earth's gravity. The atmosphere of Earth protects life on Earth by creating pressure allowing for liquid water to exist on the Earth's surface, absorbing ultraviolet solar radiation, warming the surface through heat retention (greenhouse effect), and reducing temperature extremes between day and night (the diurnal temperature variation). By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.04% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water
History of manufactured fuel gases History of manufactured fuel gases The history of gaseous fuel, important for lighting, heating, and cooking purposes throughout most of the 19th century and the first half of the 20th century, began with the development of analytical and pneumatic chemistry in the 18th century. The manufacturing process for "synthetic fuel gases" (also known as "manufactured fuel gas", "manufactured gas" or simply "gas") typically consisted of the gasification of combustible materials, usually coal, but also wood and oil. The coal was gasified by heating the coal in enclosed ovens with an oxygen-poor atmosphere. The fuel gases generated were mixtures of many