Steam

[AS.] Water in the gaseous state. The clouds of vapor wThich are seen to i ue from a kettle of boiling water are also popularly called “ steam ” but these white clouds consist chiefly of condensed steam, and do not po e the pro¬ perties which belong to steam considered as a gas. Dry steam is as much invisible as atmos¬ pheric air. Owing to the great pre ure which it exerts, to the large amount of heat which it can carry, and to the ease with which it can be condensed, steam has been found better fitted than any other gas for use in engines employed for the production of mechanical work.