ABSTRACT
First we need briefly to consider the range of phenomena that had come to fall under mechanics. They may be conveniently divided into five branches: the adjectives below are mine.
Corporeal mechanics concerned ‘ordinary-sized’ objects as found and handled on the Earth: bodies, fluids and elastic surfaces. Sound was then often
regarded as part of mechanics (Cannon and Dostrovsky 1981). In celestial mechanics the planets and satellites were taken to be point masses; prime concerns included the fine details of their orbits and rotations, the former considered also for comets. Planetary mechanics was concerned with the shape of the heavenly bodies: the Earth was the most important one, followed by the Moon. Important topics included precession and nutation, tides, and topography and cartography. Several aspects of engineering mechanics involved friction; for example, the stability of embankments and the construction and stability of buildings or structures of various kinds, such as towers, cupolas, arches and bridges. Of the many machines in this branch, several related to water, both in their design and (in)efficiency of their operation: waterwheels, turbines, pumps, valves and pistons. Connected topics included the building and steerage of boats and ships, and the use of sails. Finally, as the least developed branch, molecular mechanics treated the interaction of the supposed ‘molecules’ somehow comprising the intimate structure of matter (in, for example, elasticity and friction studies) and/or the even smaller molecules that (for some researchers) comprised the structure of the assumed aether (Körner 1904).
