“Corrugated iron is not easy to handle,” he was saying. “You need very special machines to push the iron into that shape. Do you know that, Mma Ramotswe? Do you know why corrugated iron is the shape it is?”

Mma Ramotswe had not thought about this. Corrugated iron was widely used for roofing: was it, then, something to do with providing ridges for the rain to run off? But why would that be necessary in a dry country like Botswana? There must be some other reason, she imagined, although it was not immediately apparent to her. The thought of it, however, made her feel drowsy again, and she struggled to keep her eyes open.

No, Hector Mapondise was a worthy man, but far too dull. He should seek out a dull woman, of whom there were legions throughout the country, women who were slow-moving and not very exciting, and he should marry one of these bovine ladies. But the problem was that dull men often had no interest in such women and fell for people like Mma Ramotswe. That was the trouble with people in general: they were surprisingly unrealistic in their expectations. Mma Ramotswe smiled at the thought, remembering how, as a young woman, she had had a very tall friend who had been loved by an extremely short man. The short man looked up at the face of his beloved, from almost below her waist, and she looked down at him, almost squinting over the distance that separated them. That distance could have been one thousand miles or more-the breadth of the Kalahari and back; but the short man was not to realise that, and was to desist, heartsore, only when the tall girl’s equally tall brother stooped down to look into his eyes and told him that he was no longer to look at his sister, even from a distance, or he would face some dire, unexpressed consequence. Mma Ramotswe felt sorry for the short man, of course, as she could never find it in herself to dismiss the feelings of others; he should have realised how impossible were his ambitions, but people never did.