Lecturing on Newtonian mechanics and dynamics around 1800, the natural philosopher John Dalton employed all the standard demonstrations in what had become by then a well-established genre of scientific education. On his tabletop he used oscillating devices, pendulums, balls made of various substances, levers, pulleys, inclined planes, cylinders of wood, lead in water, and pieces of iron on mercury to illustrate phenomena as diverse as gravitation, the “3 laws of motion of Newton,” impulse or the “great law of percussion,” force and inertia, specific gravity, attraction and magnetism. There was nothing extraordinary in what Dalton was doing, first in his Quaker school then at New College in Manchester. The genre of British lecturing focused on Newtonian mechanics had begun in the second decade of the eighteenth century with the travels and publications of Francis Hauksbee, Jean Desaguliers, and Willem s'Gravesande who lectured in the Dutch Republic. Dalton was deeply indebted to their legacy. His terse manuscript notes on his lectures – charred from a fire in 1940 – tell us that in one lecture he used a “machine with mercury, watercork,” and it was intended to illustrate, of all things, the effect on the planets of the “Cartesian Vortices.”

In talking about the Cartesian vortices, and in explaining how wrongheaded they had been as a conceptual device for understanding planetary motion, Dalton was repeating an old Newtonian trope. In the process he was flogging a truly dead horse. Indeed, even in French colleges after the 1750s Descartes's horse had survived only in a few places and then by artificial resuscitation.