I was riding the Long Island Railroad into New York, reflecting that the great advantage of this train is that it allows you to enjoy the scenery. The landscape doesn’t rush by in a blur, as it does when you travel on the French TGV or the Japanese Bullet Train. The Long Island Railroad train jogs sedately along at the speed of a horse and carriage, so passengers can appreciate the passing show.

It is a social and perhaps even a sociological experience because the track passes by hundreds of backyards, offering a peep show into other people’s lives. What struck me on this particular journey was how many houses had pools: big and small, above ground and in-ground, square, round and curved pools, all looking rather sad in the chilly September rain. Even if a few warm days still lie ahead, those pools are yesterday’s news. Halloween witches have already appeared in the supermarket, and the Christmas catalogs began arriving in August. The first snowstorm can’t be far away. But what do you do with a pool in winter? You can’t hide it away in the garage like a barbecue or put it out for garbage collection like a broken lawn chair.

In fact most pools lie unused most of the time, even in the best summer. Here in the northeast a pool is a very American, very optimistic investment.  In all the years I’ve traveled up and down that line I can’t remember ever seeing anyone in any of those pools. We can hear when our neighbors’ pools are in action. Apart from the splashing noises, there are shouts and screams unique to pool use, unlike any other sounds uttered by suburbanites in everyday life. But we hear these joyful sounds on only three or four hot weekends every season. It would make more economic sense for a street or a subdivision to share one big pool – but that would be communism.

Some hardy souls, who hate to waste a good investment, keep their outdoor pools running into October, and even into November. We can sometimes hear their shrieks of joy, which could almost be mistaken for shrieks of agony, when they plunge into the frigid water.

But all good things must come to an end, and a pool cannot just be ignored when winter comes. It must be expensively “closed.” This is a huge operation, comparable to mothballing in Boeing 747. Closing must be done at exactly the right moment: too early and you get algae bloom in spring, too late and you get a pool full of dead leaves. All the water must be drained out, of course, typically four or five thousand gallons, and you have to wonder what happens to all that chemical-rich water. Then elaborate rituals of purification must be carried out, with chlorine and algizide, ending with the installation of a cover strong enough to prevent visitors from the Midwest from falling right through. One advertisement in a local paper shows a baby elephant standing on the pool cover, which may be exaggeration. But it makes the point.

Closing must be a dispiriting as well as an expensive process for pool owners, especially after such a cool and rainy summer. But sometimes I think that backyard swimming pools are more symbolic than practical. Even the closed pool, its tarpaulin weighed down with rainwater and leaves, is a harbinger of hope, like the Michaelmas Feast in September, or bulbs planted in October, or spring fashions in January, or the darkness before the dawn. Summer will come again. The pool guarantees it.