When I think of Steampunk, I think of science fiction written with a 19th century understanding of science. Just as mid twentieth century sci-fi imagined a future with massive computer rooms and really shitty graphics.
Steampunk isn't necessarily set in the 19th century but it's in a future as imagined by a mind shaped by the 19th century; if that makes sense.
So to write The Mechanism, I need to think like a nineteenth century person... it's a process, okay. The summary I wrote says the story is set in 1887, or what I imagine is Nicholas Blake's "present day". The mechanism in question is sought by a lively adventuress from the 1920s, who claims that the device itself is also from there. Now the nifty part about writing the 1920s from an 1887 perspective is that, in 1887 some of the more obvious (at least in hindsight) events precipitating the Great War wouldn't have been obvious, so I, writing as Blake, don't need to worry about making the 1920s accurate as to what really happened, but a free to write them as Blake might imagine them from his current (time travel is a bitch on tense) time frame.
In other words, steam was already the greatest motive power they knew, so who could seriously imagine it changing?
I will have to do some in-depth research into the state of technology in the 1880s, and what was considered cutting edge (in 1887, Tesla was inventing his induction motor, for example). Many people believed that humanity had discovered just about everything that could be discovered.
*Note- H.G. Wells Time Machine wasn't published until 1895....
But I have a deadline to meet for Diamonds, so back to work!