The attic where I write is stifling for half of the Washington, D.C., year. But in the autumn, breezes gust through the open windows and so do the sounds of our neighborhood—children chatting on their way to school, a barking dog, the squeak of the mailbox across the street being opened, and the clang of it being closed.

Something has changed in recent years. Several times a day, a van pulls up somewhere on the street and a half-dozen Latin American men jump out. These are the leaf-blower men. A leaf-blower is basically an outsized, high-powered hair-dryer. A nine-horsepower motor, suitable for an outboard on a good-sized skiff, is mounted on a backpack and attached by a plastic tube to what looks like a giant baster.