The foundation of Western Shanghai (part two).

ON JANUARY 1, 1850, epicentre of a dramatic century, the 200-year-old British Navigation Acts were formally repealed. The acts had prohibited imports to England except on ships owned by Britons or by nationals of the country of origin of the goods. The Chinese had not been in a position to take advantage of the exception in favour of their own ships; their junks did not venture into the open seas.

In 1433, the very year in which Prince Henry the Navigator despatched the first twenty-metre Portuguese caravel with instructions to travel into the Atlantic beyond the limits of the known world at Cape Bojador, a peninsula on the West African coast 300 kilometres south of the Canaries, Admiral Zheng He had returned from the last of his seven voyages around the Indian Ocean.

Over a thirty-year period hundreds of junks, the largest 135 metres long and displacing 1500 tons--easily the largest vessels of their time--had travelled to India, the Arabian peninsula and East Africa to trade and exact tribute for the emperors of the new Ming Dynasty. However, the Ming court, succumbing to cultural chauvinism, destroyed Zheng's fleet on his return and permanently interred the world's foremost technology of ocean travel.

Nineteenth-century Westerners, who believed passionately in the unidirectional inevitability of "progress", would not have understood, having forgotten the fragility manifest in their own cultural experience of the decline of Rome, when technologies such as concrete, water reticulation, kiln-fired bricks, glassmaking and bronze working were "lost" in most of Europe for centuries.

The protective Navigation Acts, originally designed to destroy the seventeenth-century Dutch naval dominance, had created a substantial British merchant marine. It was not, however, as globally dominant as it was to become, after the reinvigorating blast of competition that began at mid-century.

The first effect of lifting the protective barriers was the loss of custom to an aggressive competitor who did not suffer from the complacent lassitude which such barriers inevitably cause. In the China tea trade, with British consumers prepared to pay a premium for freshness, American ship designers and sailors immediately established their superiority.

As that acute observer of America, the French aristocrat Alexis de Tocqueville, had reported only a few years before: "The Americans show a sort of heroism in their trading." He added: