* Bunds – waterfront roads – exist in the foreign settlements all along the Yangtze, as well as in Calcutta. But in Hong Kong the road was named the Praya, a linguistic infection prompted by the closeness of Macau, which was run by the Portuguese.

* The efforts of foreign hydrographers were once memorialized along the entire Chinese coastline, from Charlotte Point (near the frontier with today's North Korea) via Shovel-Nosed Shark Island and the Bear and Cubs (outside what was then called Ningpo), Crocodile Island and the Three Chimneys (by the former Foochow), the Cape of Good Hope and the Asses Ears (near the former Amoy), Cape Bastion (China's most southerly point) to Nightingale or Merryman's Island, in the Gulf of Tonkin. But since the 1950s these names have generally vanished. They went not only because of Communism's crusading zeal: the admiralties in London and Washington realized quite quickly that the Chinese had already named everything, and had inscribed the names on their own charts, hundreds of years before any foreign nation had even started to build ships.

* He was released in 1975 but was never allowed to publish his poems again and died in 1980. His daughter insists his heart was broken.

* And excessively bulky pigs at that: Chongming Dao pig farmers were once notorious through all China for injecting their market-bound carcasses with water, to increase the weight and the market price.

* Given that bars are created whenever one moving body of water meets another – when a river meets the ocean, or a lake, or when a river meets another river – it should be added that there is technically a second Yangtze bar, at the place where the river meets the sea, and which Victorian hydrographers named the Fairy Flats. It is two miles wide, and at one time it limited river traffic to ships drawing less than eighteen feet. On a stormy day it can be a furious place – Tennyson would have loved it. But nowadays it no longer really exists – not as a hazard to navigation. In 1935 the Whangpoo Conservancy Board embarked on a scheme to dredge five million tons of mud away from it each year: a channel through Fairy Flats, twenty-seven feet deep at least, is now permanently guaranteed.

* They already had the deck of an old Australian carrier, stripped off the hull and bolted onto an aerodrome runway near Beijing, where it was used for practice.

* Much the same atmosphere of suspicion and secrecy surrounded the construction of the first telegraph cable, which also came into China via Woosung. A Danish company built it, but was told that the infernal cable could not touch any part of the Celestial Empire, but had to be landed on a hulk, moored out in the river. The Danes ignored this and paid the cable secretly out along the Whangpoo, bringing it ashore at night, in a hut. It was some while before the Court found out, by which time the telegraph's value had been indisputably proven.