It is also the vision of steampunk, a subculture that is the aesthetic expression of a time-traveling fantasy world, one that embraces music, film, design and now fashion, all inspired by the extravagantly inventive age of dirigibles and steam locomotives, brass diving bells and jar-shaped protosubmarines. First appearing in the late 1980s and early ’90s, steampunk has picked up momentum in recent months, making a transition from what used to be mainly a literary taste to a Web-propagated way of life.