首页 / 官方藏书 / On the magnet, magnetick bodies also, and on the great magnet the earth / a new physiology, demonstrated by many arguments & experiments / Bright and conspicuous stars[230] which are not far distant from the equator which it will be useful to observe at their rising and setting: the amplitude at the Horizon on rising being known from the altitude of the pole and from the declination of the stars, by means of a globe, or tables, or an instrument whence the variation is perceived by technical calculation.