rotation. If she drops her arms (Fig. 53) she will at once spin much quicker.

I must now tell you about a very extraordinary discovery of quite recent times. I don't know whether you noticed that when we made a satellite by spinning the oil, ⁠Fig. 52.⁠Fig. 53.--> it went sailing round its planet in the same direction as the spin; and this seems natural. We should expect a planet spinning with the arrows (Fig. 54) to have a satellite like A, revolving in the same direction and not like B, revolving in the opposite direction; and yet, to our great surprise, such satellites have been discovered.