Ray Cummings 
The Girl in the Golden Atom [EPUB ebook] 

The Girl in the Golden Atom is the story of a young chemist who finds a hidden atomic world by using a super-high-powered microscope. After finding a beautiful young woman sitting before a cave he develops chemicals that will allow him to shrink and enlarge himself so he can visit the universe he has discovered. Ray Cummings was a Science Fiction author and one of the founding fathers of the Science Fiction pulp genre. He worked with Thomas Edison as a personal assistant and technical writer. He wrote 750 novels and short stories, using also the pen names Ray King, Gabrielle Cummings, and Gabriel Wilson with his most highly regarded work being The Girl in the Golden Atom.