On Energy (1875-1899)

"In no way can we get such an overwhelming idea of the grandeur of Nature than when we consider, that in accordance with the law of the conservation of energy, throughout the Infinite, the forces are in a perfect balance, and hence the energy of a single thought may determine the motion of a universe." (Nikola Tesla, "On Light and Other High Frequency Phenomena", [Lecture delivered before the Franklin Institute, Philadelphia] 1893) 

"The man of science, who, forgetting the limits of philosophical inquiry, slides from these formulæ and symbols into what is commonly understood by materialism, seems to me to place himself on a level with the mathematician, who should mistake the x's and y's with which he works his problems for real entities - and with this further disadvantage, as compared with the mathematician, that the blunders of the latter are of no practical consequence, while the errors of systematic materialism may paralyse the energies and destroy the beauty of a life." (Thomas H Huxley, "Method and Results", 1893)

"Throughout the infinite, the forces are in a perfect balance, and hence the energy of a single thought may determine the motion of a universe." (Nikola Tesla, "The Inventions, Researches and Writings of Nikola Tesla", 1894)

"We have to evolve means for obtaining energy from stores which are forever inexhaustible, to perfect methods which do not imply consumption and waste of any material whatever. I now feel sure that the realization of that idea is not far off....the possibilities of the development I refer to, namely, that of the operation of engines on any point of the earth by the energy of the medium." (Nikola Tesla, [speech] 1897)

"[…] only a part of the whole intrinsic energy of the system is capable of being converted into mechanical work by actions going on within the vessel, and without any communication with external space by the passage either of matter or of heat. This part is sometimes called the Available Energy of the system. Clausius has called the remainder of the energy, which cannot be converted into work, the Entropy of the system. We shall find it more convenient to adopt the suggestion of Professor Tait, and give the name of Entropy to the part which can be converted into mechanical work." (James C Maxwell, "Theory of Heat", 1899)

"[…] the result of the conduction and radiation of heat from one part of a system to another is to diminish the entropy of the system, or the energy, available as work, which can be obtained from the system. The energy of the system, however, is indestructible, and as it has not been removed from the system, it must remain' in it. Hence the intrinsic energy of the system, when the entropy is exhausted by thermal communication, conduction, and radiation, is equal to its original energy, and is of course greater than in the case in which the entropy is exhausted by means of the reversible engine." (James C Maxwell, "Theory of Heat", 1899)

"The Entropy of a system is the mechanical work it can perform without communication of heat, or alteration of its total volume, all transference of heat being performed by reversible engines. When the pressure and temperature of the system have become uniform the entropy is exhausted. The original energy of the system is equal to the sum of the entropy and the energy remaining in the state of uniform pressure and temperature. The entropy of a system consisting of several component systems is the same in whatever order the entropy of the parts is exhausted. It is therefore equal to the sum of the entropy of each component system, together with the entropy of the system consisting of the component systems, each with its own entropy exhausted." (James C Maxwell, "Theory of Heat", 1899)