Thanks for the date references sjm and tsuwm.

1965 R. Heinlein Farnham's Freehold No sign.. of man—not a building, a road, a path, no contrails in the sky.

Believe that's one Heinlein I missed...but even if I read it (I've always religiously kept a dictionary handy to look up new words I encounter), like Shona said, for some reason the word didn't "stick' with me.

jet stream

Sure, Faldage...meterology is one of my passions, and I'm a Weather Channel nut and hurricane aficionado. But I've always used jet streams as the first choice to describe vapor trails, and that's the term I recall most other folks using, too...could it be a regional thing?