From the time of Nelson's death at Trafalgar to the opening of the Great Exhibition in Hyde Park nearly fifty years later, London spread like a disease across the fields of Middlesex and Surrey. Foul and dangerous though it was to inhabit, in these decades London developed a new confidence in the intellectual purpose and lucrative promise of art, technology and science. This book is about the men and women who, through their genius and courage, luck and misfortune, anger and charm, put London at the cutting edge of cultural change. Theirs were the minds that moved the city that shook the world. They worked in basements and drawing rooms, in studios and museums, in learned societies and in the squalor of the debtors' prison. Charles Babbage created his calculating machines; John Martin devised a new system of clean water supply for London; John Mayall and Antoine Claudet perfected the daguerreotype; Michael Faraday harnessed electricity. They argued and fought, loved and envied, searched and dreamed, to convert the laws of nature into the purposes of life. Although it took fifty years to achieve maturity and direction, in the early decades of the nineteenth century London set itself on course to become the financial, entrepreneurial and intellectual capital of the world.