The gases or aeriform bodies afford the most remarkable instances of elasticity. When water is converted into steam it occupies a space seventeen hundred times greater than the water from which it is formed, and its elasticity causes it to expand to still larger dimensions on the application of heat. It is this peculiar property of steam, modified, as will be explained in a future part of this work, which is the foundation of its application in the movement of machinery.
All gaseous bodies are equally elastic.