"I shall be writing my lecture all day," I said busily.

At lunch I decided to have a little financial talk with Celia.

"What I feel is this," I said. "At most I can ask ten guineas for my lecture. Now my expense all the way to the North, with a night at an hotel, will be at least five pounds."

"Five-pounds-ten profit," said Celia. "Not bad."

"Ah, but wait. I have never spoken in public before. In an immense hall, whose acoustics—"

"Who are they?"

"Well, never mind. What I mean is that I shall want some elocution lessons. Say five, at a guinea each."

"That still leaves five shillings."

"If only it left that, it might be worth it. But there's a new white waistcoat. An audience soon gets tired of a lecture, and then there's nothing for the wakeful ones to concentrate on but the white waistcoat of the lecturer. It must be of a virgin whiteness. Say thirty-five shillings. So I lose thirty shillings by it. Can I afford so much?"

"But you gain the acoustics and the waistcoat."