He shall divide the day on which the Moon enters the asterism of Rohiṇī into 8 equal parts (3 hours each) commencing from sunrise—the parts representing severally the eight fortnights of the four months of the rainy season from Śrāvaṇa to Kārttika ; and he shall determine on which month or fortnight and how long there will be rain judging from the direction and duration of the wind. If the wind should blow from left to right there will be prosperity in the land; if it should blow in some fixed direction, people living in that direction will be happy.