Vapor Quotes
The male sense of space must differ from that of the female, who has such interesting, active, and significant inner space. The space that interests men is outer. The fly ball high against the sky, the long pass spiraling overhead, the jet fighter like a scarcely visible pinpoint nozzle laying down its vapor trail at 40,000 feet, the gazelle haunch flickering just beyond arrow-reach, the uncountable stars sprinkled on their great black wheel, the horizon, the mountaintop, the quasar - these bring portents with them and awaken a sense of relation with the invisible, with the empty. The ideal male body is taut with lines of potential force, a diagram extending outward; the ideal female body curves around centers of repose.
John Updike
...but suppose we were an influence (as we might be), an idea, a thing invulnerable, intangible, without front or back, drifting about like a gas? Armies were like plants, immobile as a whole, firm-rooted, nourished through long stems to the head, we might be a vapor, blowing where we listed. Our kingdoms lay in each man's mind, as we wanted nothing material to live on, so perhaps we offered nothing material to the killing. It seemed a regular soldier might be helpless without a target. He would own the ground he sat on, and what he could poke his rifle at.
T. E. Lawrence
Wherever there exists a difference of temperature... it is possible to have also the production of impelling power. ...All substances in nature can be employed for this purpose, all are susceptible of changes of volume, of successive contractions and dilatations, through the alternation of heat and cold. All are capable of overcoming in their changes of volume certain resistances... A solid... A liquid... An aeriform fluid... If it is enclosed in an expansible space, such as a cylinder provided with a piston, it will produce movements of great extent. Vapors of all substances capable of passing into a gaseous condition, as of alcohol, of mercury, of sulphur, etc., may fulfil the same office as vapor of water. ...Most of these... have been proposed, many even have been tried, although... without remarkable success.
Nicolas Léonard Sadi Carnot