These "effects" were known to travel from place to place.
Scientists thought that to do this,
the particles had to flow like fluid, be weightless (experiments to weigh heat and electricity were unsuccessful), and be able to penetrate objects. Each phenomenon was thought to be carried by different fluids, which were called "imponderable fluids so they would be completely separate The greatest interest was in heat (pp. 20-21) and electricity (pp. 22-23) and further study of these effects led in part to the downfall of this theory. By the middle of the 19th century the idea of imponderable fluids was proven to be incorrect (pp. 20-21) A large wheel rotates the globe very quickly even when the handle is turned very slowly Hand is placed o top of glass globe to produce a glow