On all the waterways of China enormous flocks of tame ducks are to be seen. These flocks generally number several thousands of birds each and are carefully herded by the duck farmer and his sons, who swim them about from place to place in search of suitable feeding-grounds. On the Yangtse I have seen them in mid-stream floating down in compact masses with the racing current and surrounded by their guardians in tubs, who, armed with long bamboos, smartly whack any bird which may happen to stray away from the flock until it rejoins its companions.
These ducks are apparently always of one age, be it a month, three months or full-grown, which fact had ever been a source of mild surprise to me, in view of the number of simultaneous broods which would be necessary to hatch off such swarms, until the matter was explained.
A friend of mine gave a tiffin party of four good men and true on his stern-wheel house-boat, the motive power for which was supplied by half-a-dozen coolies driving the wheel with their feet, on the same principle as the tread-mill, and we were gliding up the Taipa Channel near Macao at about four knots, when suddenly our craft came into a sea of egg-shells sailing gaily before the breeze and having at a short distance much the appearance of water-lilies.
For a quarter of an hour or so we ploughed through these shells, which must have numbered tens of thousands, making various conjectures as to their origin, until our host, who had been below superintending the icing of the champagne, came on deck and explained that they undoubtedly were from an incubator in which ducks had just been hatched. This was new to me, so I asked him for details, but he replied that beyond knowing of the incubators and that they were made of manure and lime in which eggs were buried until hatched, he had not been able to procure further information.
Since then I have made many inquiries, but the Chinese will reveal little beyond the fact that incubators "have always existed" for the hatching of ducks and geese.
A gentleman whose knowledge of the Chinese and their ways is unsurpassed has also kindly tried to find out, but with limited success, for, he says, it is regarded as a trade secret and the duck farmers will not divulge the process. However, he ascertained that the hatching takes place in early spring, when "a kind of primitive incubator is used. The eggs are placed in a big basket covered with straw or cotton wool, about a thousand eggs in one basket. Under this basket a charcoal fire is lit to keep the required temperature. The work is carried on in closed rooms and one man is always in attendance turning the eggs. Only eggs of ducks and geese are thus treated."
Whether these incubators are made of manure and lime in the open air, whether they are in rooms heated by charcoal fires, or whether there are both kinds, the interesting fact is established that incubators "have always existed" in China, while results, as seen in the huge flocks of ducks, proclaim them as thoroughly successful. And this, too, when it has been unreservedly believed that the incubator was a modern triumph of Western science!
Another little matter has attracted my attention. There have lately been paragraphs in several papers announcing the excellent results obtained from a new system of registering criminals by means of thumb-marks.
Thumb-marking may be new to Scotland Yard, but in China it is a very ancient practice. I have seen illiterate men smear their thumbs with ink and make impressions at the foot of documents, such thumb-marks being accepted as in every way equivalent to full signatures.