What happens... in a steam-engine... ? The caloric developed in the furnace by the effect of the combustion traverses the walls of the boiler, produces steam, and in some way incorporates itself with it. The latter carrying it away, takes it first into the cylinder, where it performs some function, and from thence into the condenser, where it is liquefied by contact with the cold water... [T]he cold water of the condenser takes possession of the caloric... It is heated by the intervention of the steam as if it had been placed directly over the furnace. The steam is here only a means of transporting the caloric.

I have endeavoured to attain this end (viz. the production of a vacuum in the cylinder) in another way. As water has the property of elasticity, when converted into steam by heat, and afterwards of being so completely recondensed by cold, that there does not remain the least appearance of this elasticity, I have thought that it would not be difficult to work machines in which, by means of a moderate heat and at a small cost, water might produce that perfect vacuum which has vainly been sought by means of gunpowder.

We dig up what is left of life crushed to carbon beneath us, and we burn it: to make important things, really—hospital intensive care units, synthetically derived insulin and steel beams for the new high school library. But we burn it for nothing, too, really, for vanity and emptiness.

To condense fact from the vapor of nuance.

The steam-engine having furnished us with a means of converting heat into a motive power, and our thoughts being thereby led to regard a certain quantity of work as an equivalent for the amount of heat expended in its production, the idea of establishing theoretically some fixed relation between a quantity of heat and the quantity of work which it can possibly produce, from which relation conclusions regarding the nature of heat itself might be deduced, naturally presents itself. Already, indeed, have many successful efforts been made with this view; I believe, however, that they have not exhausted the subject, but that, on the contrary, it merits the continued attention of physicists... The most important investigation in connexion with this subject is that of S. Carnot.

steam boiler, delivering so and so many pounds of steam to its engines as long as the envelope can contain the pressure; but let a breach in its continuity arise — relieving the boiling water of all restraint — and in a moment the whole mass flashes into vapour, developing a power no work of man can oppose.

Nature, in providing us with combustibles on all sides, has given us the power to produce, at all times and in all places, heat and the impelling power which is the result of it. To develop this power, to appropriate it to our uses, is the object of heat-engines.

Steam is the friend of man. Steam engines are very human. Their very weaknesses are understandable. Steam engines do not flash back and blow your face in. They do not short-circuit and rive your heart with imponderable electric force. They have arms and legs and warm hearts and veins full of warm vapour. Give us steam every time. You know where you are with steam.

By another way, therefore, I endeavoured to attain the same end; and since it is a property of water that a small quantity of it, converted into steam by the force of heat, has an elastic force like that of the air, but, when cold supervenes, is again resolved into water, so that no trace of the said elastic force remains; I felt confident that machines might be constructed wherein water, by means of no very intense heat, and at small cost, might produce that perfect vacuum which had failed to be obtained by aid of gunpowder. But of the various constructions which can be contrived for this purpose, the following seemed to me to be the most suitable.

The properties of the air are such that it may become condensed or rarefied.

How shall we escape the heat?” — meaning, of course, the heat of suffering. He answered, “Go right into the middle of the fire.” “But how, then, shall we escape the scorching flame?” “No further pain will trouble you!

I think we have generated as much light as we are going to...And as much heat as we ought to.

Perhaps the fires through which I had passed would have a purifying effect on me, just as a blast furnace burns the impurities out of steel.

Heat can evidently be a cause of motion only by virtue of the changes of volume or of form which it produces in bodies.