Can Science Education Research Give an Answer to Questions posed by History of Science and Technology? The Case of Steam Engine’s Measurement

According to the principle of virtual velocities, if on a simple machine in equilibrium we suppose a slight virtual movement, then the ratio of weights or forces equals the inverse ratio of velocities or displacements. The product of the weight raised or force applied multiplied by the height or displacement plays a central role there. British engineers used the same product in the eighteenth century in order to measure steam engines’ effectiveness. The question is whether this measure was obviously empirical or had its origin in theory of mechanics and particularly in the principle of virtual velocities. According to science education research, this measure is not likely to have arisen intuitively and most probably could not have been formulated without any acquaintance with theory of mechanics.