These drawings are by architectural draftsman Hugh Ferriss . His work is really incredible and demonstrates a fantastic imagination (not to mention patience). I prefer the style of the lighter, more detailed images, but I enjoyed the story behind the last few charcoal renderings. They are from The Metropolis of Tomorrow, where Ferriss imagined what a future megacity might look like. Delineator of Gotham indeed.
I recommend looking through this epic Flickr set to see more of his work.