The Bonnet in the Park — Acres of Diamonds

John Jacob Astor forecloses on a failing millinery store, keeps the same struggling owners and the same capital, and adds nothing but his own attention: he sits on a park bench for hours studying exactly which bonnets women passing by actually respond to, then tells the shop precisely what to stock before it is even made. The store's fortunes reverse immediately, without a single extra dollar of investment.

Conwell applies the same principle to manufacturing without capital. A jobless carpenter in Hingham, Massachusetts, whittles a toy chain from a soaked shingle to settle his children's argument, then, prompted by a neighbor, actually asks his own children what toys they want instead of guessing, building unpainted Hingham toys into a hundred-million-dollar fortune using firewood and a single penknife as his only capital.

A New Britain, Connecticut woman, frustrated when her collar-button jams, decides on the spot to invent something better. Her husband mocks the idea, but she invents the snap fastener anyway, building enough wealth from it to sail the ocean each summer with her husband in tow. Conwell closes by dismantling the claim that women never invent anything, crediting Mrs. Jacquard for the Jacquard loom, farmers' wives for the printing press and roller, and Mrs. General Greene for the actual idea behind the cotton gin, which Eli Whitney patented in his own name, setting up the next chapter's reveal about who truly invented the sewing machine.