Author and book title that includes "The Slow Ones"

Question

I am looking for the author and book title that included a short story I think was called "The Slow Ones".

On this planet is found large circular basalt-glass lakes of unknown origin. Around these objects the native population has developed a culture wherein skating on and in particular, winning competitions of skating on these objects is the main focus of the story and the protagonist attempting to win a particular race. Weird Hans Brinker in a way.

Meanwhile, and to the natives considered unrelated to the skating rinks, there also exist what the reader sees as anomalously floating cylinders whose existence is simply accepted by the natives.

Well, turns out these cylinders are missiles that are lofted between warring interstellar parties and in-transit are known to occasionally loiter for generations a few feet above the ground of the story's main planet before mysteriously vanishing, because the planet happens to be favorably situated in space/hyperspace or something like that for the advanced physics of the targeting used by the warring parties. Sometimes, perhaps once in a million years, these missiles explode while still hovering over the planet and create a new basalt-glass rink.

Answer 1

This is Ian Watson's "Slow Birds" (1983). It was first published in The Magazine of Fantasy & Science Fiction and variously anthologized.

Skating races on plains of glass:

By late morning, after the umpires had been out on the glass plain setting red flags around the circuit, cumulous clouds began to fill a previously blue sky, promising ideal conditions for the afternoon's sport. No rain; so that the glass wouldn't be an inch deep in water as last year at Atherton. No dazzling glare to blind the spectators, as the year before that at Buckby. And a breeze verging on brisk without ever becoming fierce: perfect to speed the competitors' sails along without lifting people off their feet and tumbling them, as four years previously at Edgewood when a couple of broken ankles and numerous bruises had been sustained.

After the contest there would be a pig roast; or rather the succulent fruits thereof, for the pig had been turning slowly on its spit these past thirty-six hours. And there would be kegs of Old Codger Ale to be cracked. But right now Jason Babbidge's mind was mainly occupied, with checking out his glass-skates and his fine crocus-yellow hand-sail.

The appearance of the titular "slow birds:"

They were called slow birds because they flew through the air — at the stately pace of three feet per minute.

They looked a little like birds, too, though only a little. Their tubular metal bodies were rounded at the head and tapering to a finned point at the tail, with two stubby wings midway. Yet these wings could hardly have anything to do with suspending their bulk in the air; the girth of a bird was that of a horse, and its length twice that of a man lying full length. Perhaps those wings controlled orientation or trim.

They blow up a lot more often than once in an million years though:

Not always, though. Half a dozen times a year, within the confines of this particular island country, a slow bird would reach its journey's end.

It would destroy itself, and all the terrain around it for a radius of two and a half miles, fusing the landscape instantly into a sheet of glass. A flat, circular sheet of glass. A polarised, limited zone of annihilation. Scant yards beyond its rim a person might escape unharmed, only being deafened and dazzled temporarily.

As I noted it's been in several anthologies notably Dozois' Year's Best Science Fiction, First Annual Collection and Carr's The Best Science Fiction of the Year #13 (both 1984) as well as the collection *Slow Birds and Other Stories (1985).

You can read it in its original publication at the Internet Archive.