Page:Popular Astronomy - Airy - 1881.djvu/292

278 to his own, but in the opposite direction. To him it will therefore appear to revolve from east to west about the line NA, making a complete revolution in the course of a day. At the South Pole a similar appearance would be observed.

At places situated elsewhere on the earth's surface, it is less easy to anticipate the result; but some idea of the effect produced on the plane of vibration may perhaps be conveyed by the following explanation.

It has been remarked above, (page 108,) that a single force, acting in a given direction, may be resolved into two forces acting in given directions: and that these two forces acting together may be