Some Characteristics of Steampunk

Within the genre of Steampunk lies a multitudinous array of characteristics. The style of writing is very gothic. The setting is generally very dark and gloomy, almost post-apocalyptic. Stories typically take place during the Victorian era. The world has either already been met with disaster or there is an impending disaster that needs to be stopped quickly. Although the era is mid-to-late 19th century, there is a wide spectrum of highly technological devices. These devices, although very advanced (even for our time), are bound by 19th century scientific developments (e.g. The Steam Engine). One of the main characters is typically a scientist, be it the protagonist or the antagonist. The genre seems to be heavily influenced by both Mary Shelley and H.G. Wells. There is also a somewhat widespread interest in the animation of nonliving matter.
Although there are more characteristics behind this genre, I cannot think of any at the moment.