HOW IT WORKS.

less power, owing to its being so much further away. At certain periods of the month, sun, earth, and moon are all in line. Sun and moon then pull together, and we get the highest, or spring tides (Fig. 232). When sun and moon pull at right angles to one another—namely, at the first and third quarters—the excrescence caused by the moon is flattened (Fig. 233), and we get the lowest, or neap tides.