1890 Shadows of the Empire

From publisher blurb:

Victorian England by Gaslight

The British Empire is at the height of its power, and no city on Earth is as rich and as decadent as London. In the corridors of power, civil servants enact the iron will of the aristocracy, and ladies and gentlement of breeding dance the night away at glorious balls. Mighty Zeppelins dot the London skyline and in foundries powered by the spoils of the Empire, the greatest engineers of the age create marvels of steam.

But admist the glitz and finery, the seedier side of Empire lurks: a killer roams the slums of London, and the East End is "a horrible black labyrinth, reeking from end to end and swarming with human vermin, whose trade is robbery and whose recreation is murder."