L. R. Curtiss

“ All the mechanical power which comes from the combustion of fuel and all the muscular force of the animal kingdom is but the transmutation of solar energy through the mediumship of plant-life. Well might we say, as did the pagans of old, "We are children of the sun." ”

“ The current of scientific thought tends to demonstrate that all the phenomena of Nature are to be regarded merely as varieties of motion, one guiding principle of which is conservation of energy. This being an established fact in science, it fortifies us in our position of reasoning downward in the direction of primary causes. By conservation of energy we are to understand that, while matter exists throughout the universe in definite quantity, there is also existing, as an attribute of matter, a definite amount of energy or force ”

“ Or, again, dynamics is that branch of science which measures the energies producing motion as well as those produced by motion, and is divided into two parts—kinematics, which pertains to motion without regard to the bodies acted upon; and kinetics, which refers to the cause of energies whereby motion is given to bodies, each of which is the antithesis of static energy or energy at rest. Molecular dynamics has for its domain the actual working forces inherent in the atoms and molecules of matter. ”

“ Waves of ether may conduct a store of energies across the universe and invest them in a wealth of carbonaceous flora; these energies may lie dormant in vegetable fossils for untold eras; man may delve in mines and exhume the coal, and enlist the aid of oxygen to break the bonds of chemical affinity, setting free those energies stored away in the countless ages of the past ”

“ The inherent measure of force possessed by each and every atom is its kinetic energy, and this energy is the correlative and antecedent of all the modes of force which characterize the various phenomena of the visible universe. The condition in which matter presents itself to our senses depends upon the degree in which these several forces are made manifest. All the phenomena of Nature consist in transformations of energy only, the working force of the universe being previously invested in the kinetic energy of its atoms. ”

“ Imagine the particles of the air we breathe flying about at the rate of eighteen miles per minute—a velocity exceeding that of a cannonball—a velocity which, if the particles were all moving in one direction, would constitute a tornado ten times more violent than any terrestrial hurricane! ”

“ Beautifully and symmetrically the forces of Nature built up the crystalline mass, and as silently and surely the sun's competency of heat will effect its liquefaction. Thus far we have seen the atoms accelerating in velocity by virtue of the energy imparted by the solar-heat waves, and all this time they are vibrating within the definite limits of the molecule. A further increase of heat will increase the motion of the atoms, thus tending to a rupture of the bonds of cohesive attraction. ”

“ Were it possible to magnify the atoms of matter to a diameter available for distinct vision, we should be met at the outset by a difficulty too astounding for realization. It is a matter of easy proof that the magnifying of any object while in motion will exhibit that motion increased in velocity just as many times as the diameter of the object is augmented. ”

“ It is competent to solve the dynamical problems of vital and physical phenomena, demanding from every antecedent its consequent, and exacting from every consequent an equivalency of antecedent. All sound experience of whatever kind justifies this affirmation. These views compel the idea of the universality of motion, and that force is the eternal causation of each and every phenomenon, and that the existing relations between matter and force remain constant throughout the universe. ”

“ The potential energies of the atoms of matter, in their free condition, are almost beyond human comprehension. Thus, heat a pound of charcoal to the point of incandescence. The vibratory motion of the atoms of carbon will then have reached an amazing velocity; oxygen rushes in to form new compounds; the oxygen-atom, by its impact upon the coal, has its motion of translation converted into vibratory motion, which immediately appears as heat. The clash of these atoms makes up the sum total of the energies of the combustion. ”

“ By the term "mode of motion" is meant the manner in which energies are made sensible to our understanding. Thus, the terms heat, light, etc., are but familiar ones by which we express the various modes in which force is exhibited to our senses in its action upon matter. Conservation of energy was denominated by Faraday as "the highest law in physical science which our faculties permit us to perceive." Its unfoldings mark an intellectual epoch which divides the old from the new. It teaches of the unity of the universe ”

“ The struggle goes on until the ice melts, by which process we have solar energy conserved in the latent heat of water. The molecules being thrown almost beyond the range of cohesive force, their movements are no longer confined to their former limits, but may extend throughout the length and breadth of the mass. This is the fluid state. The amount of energy required to swing the atoms so nearly beyond the range of cohesive attraction, or simply to melt the ice, is equal to 500 tons raised one foot high. This force still exists as transmuted energy, and is the latent heat of water. ”

“ Any further division destroys the entity of the compound, and results in the decomposition of the salt into the atoms of its elements. Hence a simple molecule is the smallest portion of any chemical compound that is not susceptible of subdivision without destroying its entity, or, in other words, the smallest number of atoms that can cohere to form a compound constitute the molecule of that compound. An atom is designated as the ultimate particle of any elementary body, and is not susceptible of any further division within the range of human analysis. ”

“ The question of the infinitely large and the immeasurably small has engaged the attention of philosophers since the days of Democritus. Modern investigators are, however, in possession of experimental data that aid them in arriving at facts with ever-increasing accuracy. We have the atomic theory first placed upon a substantial basis by Dalton, which treats of the atomic constituents of matter, and gives to each atom a definite size and weight, and establishes the proposition that atoms combine to form molecules, and that molecules aggregate to masses. ”

“ IN entering upon an analysis of the subject of atomic and molecular magnitudes, it is desirable that we should have as clear an idea of the immeasurably small in Nature as possible. To the astronomer the size and relative distances of the celestial bodies are real magnitudes, and so also, to the molecular physicist, the magnitudes verging upon the infinitely small are just as much of a reality. The billionth part of an inch is just as much of a fact as a billion miles.
The mathematical definition of a point consists in stating it as a locality without length, breadth, or thickness ”

“ Each and every ball interposed will have the motion of its constituent particles augmented by an amount of energy of motion exactly equivalent to that parted with by the larger ball; and, when the moving ball finally comes to rest, the sum total of molecular energies in the interior of each ball is exactly equal to the original momentum of the larger ball. ”

“ The locking up of potential energy in the protoplasmic cell of the plant requires the expenditure of a vast amount of energy, but the solar ray, aided by the subtile alchemy of the leaf, is competent for the task; and, while the chlorophyl of the leaf assists in weaving organic tissues from the air, this outward dissipation of energy is delayed for a while, giving us food for our bodies and fuel for our fires. ”

“ Atoms and molecules may vibrate to and fro, or may execute various oscillations about each other, with a moderate velocity, or perform their motions with a rapidity beyond conception; and be the intensity of the vibrations ever so great or ever so small, these same vibrations determine the amplitude of the ethereal waves—those waves of greatest length giving rise to all the phenomena of radiant heat, while shorter ones constitute light in all its luminous and chromatic effects ”

“ In the animal kingdom are found myriads of forms so minute that their bulk is reckoned by less than the millionth part of a cubic inch, yet each one is endowed with organs of sense or assimilation sufficient to serve the purpose in their sphere of life. The vegetable kingdom, also, offers abundant specimens of microscopic forms, calculated to excite our admiration by the beauty and minuteness of their organisms. ”

“ The new philosophy, however, teaches that, since molecular motion refers to the invisible movements of the particles of the mass, there is no such thing as complete rest of the ultimate particles of matter short of absolute zero of temperature, which, if universal, means total frigidity of every sun and orb in the universe. ”

“ Thus the aggregated energies required to set free the oxygen and hydrogen in our nine pounds of ice are equivalent to the raising of a ton's weight 28,000 feet, and we now have the original nine pounds of gas, laden with the potential energies of 56,000,000 foot-pounds, which is just equivalent to the requisite liberation of force necessary to reduce the gases back again to the solid form of ice. ”

“ It is enough to say that it answers our purpose in giving a satisfactory explanation of a large class of natural phenomena as they are exhibited to us in daily life. But, as we know the favored ideas of scientists and scholars in generations preceding ours have given way to newer and better ones, so, in turn, the popular conceptions of to-day may serve as stepping-stones to coming ideas, each destined to take its place as the predecessor of a higher and better intelligence. ”

“ Small as these atoms are, we are not permitted to stop here, but remember that there is a finer medium environing them all, embracing possibly a complexity of internal structure sufficient to baffle human investigation for all time. This cosmic or luminiferous ether is supposed to fill all space, intermolecular and interstellar, and to be the medium in which the atoms and molecules move like motes in the sunbeam. ”

“ That is, matter and force are both indestructible, but force or energy (synonymous terms) is convertible into the several modes of force. The attributes of matter are attraction of gravitation, attraction of cohesion, and chemical affinity. ”

“ As an illustration of this interchangeableness of force: suppose two files of men to be arranged in proper order, between which we roll a cannon-ball with a certain initial velocity. This ball runs the gantlet of those files of men, it being the individual duty of each man to retard the momentum of the ball by interposing his hand in its path. It is evident that each hand so interposed will receive a shock, the force of which is just equivalent to the amount parted with by the ball itself. ”

“ The amount of energy expended in winding up the weight, less the friction, is exactly equivalent to the potential energy of the weight so raised, also to the dynamic energy given out by its falling or running down. ”

“ The concussion of atoms at the union of eight pounds of oxygen with one pound of hydrogen sets free an amount of energy, in the form of heat, equivalent in mechanical value to 47,246,400 pounds let fall one foot, or the crash of a ton's weight as an avalanche down a precipice of 23,623 feet. ”

“ The actual amount of dynamical energy set free by the union of this pound of charcoal with atmospheric oxygen is equivalent to the mechanical raising of eleven and a quarter million pounds one foot high. Let us further consider the dynamical forces inherent in the molecules of free gases, and look to a molecular explanation of the three states of matter, the solid, fluid, and gaseous. In solids the atoms are held together with a rigidity that develops the full strength of cohesive force. ”

“ It follows, since human skill is incompetent to penetrate by any mechanical means into the internal structure of matter, that we shall be compelled to direct our labors to other modes of investigation if we would know more of the atomic structure of matter, possessing as it does a minuteness far surpassing the analytical power of the microscope ”

“ Notwithstanding the almost infinitesimal magnitudes of the organic world, human skill is able to compete in the matter of minuteness. Platinum wire has been drawn so fine as to rival in minuteness the smallest fibre of the spider's web. ”

“ Thus the number of atoms in one cubic inch of hydrogen-gas, at the temperature of freezing water and under the pressure of one atmosphere, is given in the neighborhood of three hundred millions of millions of millions, each atom possessing an initial velocity of over a mile per second, covering nearly eighteen billions of oscillations in different directions in the same second of time. ”

“ If you push endwise against a stick of wood, the force applied will immediately appear at the other end. This is transmission of force by means of molecular action. The force being applied to one end of the bar is transmitted from particle to particle with great velocity its entire length. ”

“ Gold has been deposited upon the surface of other metals, and drawn to such extreme thinness that a thousand-millionth part of a grain exhibited the visible characteristics of the metal. The oscillations of the horizontal pendulum can be measured to the 180000000 inch, by the aid of a small mirror, a beam of light, and a graduated scale for reading the vibrations. ”

“ The original momentum of the ball has for its equivalency the sum total of the lesser energies imparted to the several hands interposed. Or again, if, instead of hands interposed, we substitute a row of smaller balls, and let them receive the impact of the moving one, the result will be just the same. ”