OCR Text |
Show j Weight of Atmosphere. Atmosphere is the name applied to the gaseous envelope that surrounds the globe. It consists of a mechanical union of nitrogen and oxygen Jn the ratio of four to one, together with a relatively small amount of carbonic acid gas and a little water vapor. Its thickness thick-ness is about fifty miles, although it probably extends in an attenuated form as far as 500 miles. This is inferred from the observation of luminous meteors. me-teors. It exerts a pressure of fifteen pounds to the square Inch at the earth's surface and weighs over eleven and a half trillions of pounds. Each adult inhales one gallon of air per minute and consumes thirty ounces of oxygen daily. An ordinary gas jet consumes as much oxygen as five persons. |