comment on structure

The book is divided into 4 sections. Part 1: Three-Way Race; Part 2: Chain Reactions; Part 3: How to Build an Atomic Bomb; and Part 4, Final Assembly. Part 1 has 7 chapters. Each is titled with words rather than numbers. They are Skinny Superhero; The U Business; Finding Einstein; Tradecraft; Rapid Rupture; Norway Connection; and Enormoz. Part 2 has 8 chapters. They are On the Cliff; International Gangster School; Gliders Down; Quiet Fellow; Disappearing Scientists; Chicago Pile; Operation Gunnerside; and High Concentration. Part 3 has 9 chapters. They are The Gatekeeper; The Gadget; Laboratory Number 2; Ferry Job; Dirty Work; Secret Cities; Man with Four Gloves; Born Rebel; and Two Inside. Part 4 has 13 chapters. They are The Pilot; Swiss Deal; Implosion; Falling Stars; Land of Enchantment; Trinity; Test Shot; Little Boy; Hiroshima; Reaction Begins; End Game; Father of the Bomb; and Fallout.