This introduction presents an overview of the key concepts discussed in the subsequent chapters of this book. The book draws out the politics of naval architecture, authority and technology in nineteenth-century Britain by using the motif of ship design. It examines the design and trials of HMS Vernon, one of William Symonds's most controversial vessels. The book examines the reconstructions of the Royal Navy, restoring them to the flows and currents of nineteenth-century history without treating them as simple products of contemporary politics and strategy. It also examines the ways in which ship designers, politicians and engineers shaped the history of steam in the Navy. The book explores the tensions between naval administrators and a group of ship designers and men of science who increasingly identified with the title 'naval architect'.