For much of this story, our attention has focused on events within the isle of Great Britain, and with good reason: primed by the virtuous cycle of coal, iron, and steam, the depth and breadth of Britain’s exploitation of steam power far exceeded that found anywhere else, for roughly 150 years after the groaning, hissing birth cry of steam power with the first Newcomen engine. American riverboat traffic stands out as the isolated exception.
But Great Britain, island though it was, did not stand aloof from the world. It engaged in trade and the exchange of ideas, of course, but it also had a large and (despite occasional setbacks) growing empire, including large possessions in Canada, South Africa, Australia, and India. The sinews of that empire necessarily stretched across the oceans of the world, in the form of a dominant navy, a vast merchant fleet, and the ships of the East India Company, which blurred the lines of military and commercial power: half state and half corporation. Having repeatedly bested all its would-be naval rivals—Spain, the Netherlands, and France—Britain had achieved an indisputable dominance of the sea.
The potential advantages of fusing steam power with naval power were clear: sailing ships were slaves to the whims of the atmosphere. A calm left them helpless, a strong storm drove them on helplessly, and adverse winds could trap them in port for days on end. The fickleness of the wind made travel times unpredictable and could steal the opportunity for a victorious battle from even the strongest fleet. In 1814, Sir Walter Scott took a cruise around Scotland, and the vicissitudes of travel by sail are apparent on page after page of his memoirs: