The light ages - Ian R MacLeod

Through the power of Aether, England has created a mighty Industrial Age. In this era of greatness, Robert Borrows, the insignificant son of a Lesser Toolmaker, holds the key to the world's future.
Raised in the Yorkshire town of Bracebridge, a place dominated by the pounding of mighty subterranean engines, Robert sees the way in which proximity to aether csn poison a life when his mother gradually becomes the thing that all families dread - a changeling; less than human, terrible to see. Fleeing to London, he encounters the beautiful, mercurial and mysterious Anna Winters, who he first met on a trip with his mother, in happier times. Exploring the vast, Brobdignagian city, all colours, smells and danger, Robert discovers secrets that will lead him back towards the clouded hills of Bracebridge and the deepest mysteries of aether. For all is not well in England's green and pleasant land.
This Age is ending, in fire and in death...