BOOK II. xcviii. 2II-XCIX. 214 



quake is always followed by forty days' fine weather. 

 Corn sown in the Arpi district does not come up, and 

 at Mucian Altars in the district of Veii and at Tus- 

 culum and in the Ciminian Forest there are places 

 where stakes driven into the gi-ound cannot be pulled 

 out. Hay grown in the Crustumium district is noxious 

 on the spot but healthy when conveyed elsewhere, 



XCIX. About the nature of bodies of water a ndes, theot 

 great deal has been said. But the rise and fall of °^' 

 the tides of the sea is extremely mysterious, at all 

 events in its irregularity ; however the cause Ues in 

 the sun and moon. Between two risings of the moon 

 there are two high and two low tides every 24 hours, 

 the tide first swelHng as the world moves upward 

 with the moon, then falHng as it slopes from the mid- 

 day summit of the sky towards sunset, and again 

 coming in as after sunset the world goes below the 

 earth to the lowest parts of the heaven and approaches 

 the regions opposite to the meridian, and from that 

 point sucking back until it rises again ; and never 

 flowing back at the same time as the day before, just 

 as if gasping for breath as the greedy star draws the 

 seas with it at a draught and constantly rises from 

 another point than the day before ; yet returning 

 at equal intei-vals and in every six hours, not of each 

 day or night or place but equinoctial hours, so that 

 the tidal periods are not equal by the space of 

 ordinary hours whenever the tides occupy larger 

 measures of either diurnal or nocturnal hours, and 

 only equal eveiywhere at the equinox." It is a vast 

 and illuminating proof, and one of even divine 

 utterance, that those are dull of wit who deny that 

 the same stars pass below the earth and rise up again, 

 and that they present a siuiilar appearance to the 



343 



