History is a record of acts, and not of dreams. And yet the greatest acts were dreamed of before they were performed. Every process, no matter how small or how great, seems to proceed by three stages--conception, development and production. Most of our acts are almost automatic, and the three stages succeed each other so quickly that only the final stage itself is noted. But the greatest acts, from which great results have followed, have begun with the conception of a picture not of an ordinary kind, such as a great campaign, a new machine, a novel theory, a book, painting, statue or edifice:--then a long process of development, during which the conception is gradually embodied in some concrete form, as, for instance, a statue, a painting or an instrument;--and then production. _Finis opus coronat, the end crowns the work_; but the work is not crowned until it is finished, and a concrete entity has been brought forth. Lavoisier finished his work. Not only did he dream a dream, but he embodied his dream in a definite form, and gave it to mankind to use. Dalton did similarly. This does not mean that their work was not improved upon thereafter, or that they invented the chemistry of today. They merely laid the foundation of chemistry, and placed the first two stones. A remarkable exemplar of the meaning of this declaration was Benjamin Thomson, who was an American by birth, but who entered the Austrian Army after the War of the Revolution, and made an unprecedented record in the application of physical and chemical science to the relief of the distressed and ignorant and poor, especially the mendicant classes. For his services he was made Count Rumford. His researches were mostly in the line of saving heat and light, and therefore saving food and fuel. He ascertained by experiments of the utmost ingenuity and thoroughness that the warmth of clothing was because of the air entangled in its fibers; he investigated the radiation, conduction and convection of heat, analyzed the ways in which heat could be economized, and invented a calorimeter for testing the heat-giving value of different fuels. In 1798 he had noted the fact that heat was developed when cannon were being bored. He immediately conceived the idea that the heat developed was related to the amount of work expended driving the boring tool, and invented a means of measuring it. This consisted simply of a blunt boring tool that pressed into a socket in a metal block that was immersed in water, of which the temperature could be taken. To get a basis for his investigations into the problem of lighting economically the dwellings of the poor, Rumford invented a photometer for measuring illumination. No man in history shows more clearly the co-working of a high order of imagination, and a careful and accurate constructiveness; and no man ever secured more intensely practical and beneficent results. In the hospital at Verona he reduced the consumption of fuel to one-eighth.