"Why, then of course it would have been raining the whole time at B."

"Where would A have got its rush of air from then?"

"From the place C."

"Is it fine there?"

"No, it's raining. It is like B was after the air rose at A."

"Oh. Then whatever happens at these places, A, B and C, it _must_ rain."

"More or less, yes. More really."

"Are there any more places? I mean, if I am at A where ought I to go?"

"There is a place, D--"

"What happens there?"

"Conditions are favourable for the formation of secondary depressions."

"Then where do you advise me to go?"

"I'm not advising you. You asked me to explain the weather, and I have."

"I think you have. I understand it now."

* * * * *