global rich list

Necessity Is the Mother of Invention

In a culture that hails mobile phones and plasma-screen televisions as the great innovations of our time, Smith is gloriously out of step. She designs medical devices and labor-saving machines for people who live at the far end of dirt roads in Africa. Her inventions cost anywhere from a few hundred dollars to a few pennies. ”You can’t understand how important a grain mill is,” she says, ”until you’ve spent three hours pounding grain and gotten a cup and a half of flour.” It is this kind of understanding — of tedium, of tired muscles, of hunger pangs — that Smith brings to her work.