This Chapter of From Hell makes heavy usage of the concept of psychogeography. Moore draws a lot of stuff here (especially the stuff about the Hawksmoor churches and some of the significance of the siting of the Ripper murders) from two books of poetry by Iain Sinclair: <em>Lud Heat: A Book of the Dead Hamlets</em> and <em>White Chapell, Scarlet Tracings</em>. If you really want to go deep into this chapter they're worth picking up. Here as well is an essay that might be of interest, <em>English History as Jack the Ripper Tells It: Psychogeography in Alan Moore’s From Hell</em> by Ann Tso.