[VOL IV] THE MELON ISLANDS, AND AN IRRIGATING WHEEL

THE MELON ISLANDS, AND AN IRRIGATING WHEEL

Cover Image: The Melon Islands, and an Irrigating Wheel / GuaZhou YangZhou JingSu / Drawn by T. Allom Engraved by H.Alard – ALAMY Image ID:2X55ND3

*The Melon Islands（Guazhou） is located in present-day Yangzhou City, Jiangsu Province, China. Situated at the confluence of the Beijing-Hangzhou Grand Canal and the Yangtze River, it serves as a crucial transportation hub. Ancient people constructed numerous hydraulic facilities in this region. Waterwheels, believed to have emerged between 25 AD and 220 AD, are an integral part of China’s agricultural heritage.

To various use their various streams they bring,
The people one, and one supplies the king.

GARDENS OF ALCINOUS.

MODES of raising water with facility from wells and rivers, for domestic and agricultural purposes, must have been peculiarly studied by Eastern nations, where the soil is arid—the atmosphere sultry. The Athenians, in their earliest ages, had no other beverage than water, hence the loud praises of its merits by their chiefest poets: but they did not then possess any mechanical contrivances for raising it to the surface. Near the mouth of each public well a cylinder of marble was fixed, up the side of which the laden bucket was drawn by a hand-rope, a fact distinctly attested by grooves of some inches in depth, worn in the stone by the friction of the rope. To this rude mode the aqueduct succeeded, on which the great cities of antiquity appear to have expended an extravagant share of labour. The Thracians improved on the Athenian plan, by cutting a spiral staircase down into the rock, and arching over the well, by which the rope and bucket were superseded. Before the invention of pumps the Thraianc wheel was familiar in Great Britain, and, at an earlier period, was passed in the VIIIth Henry’s reign for the special protection of one of these primitive fountains at Hampstead, about five hundred yards below the church, “that the citizens of London might obtain water from the bottom of the heath.” In Roumelia, water for irrigation was raised by a lever, having a bucket at one end with a counterpoise of stones at the other; a plan still practised by the Chinese. There, every cavity is made tributary to the supply or preservation of water; and fountains, or large reservoirs, are almost held in reverence.

It is unnecessary to dwell upon the care bestowed by ancient governments in affording a sufficient supply of pure water to large assemblages of people. The Claudian aqueduct extended fifteen miles, and was carried to Rome on arches a hundred and nine feet high. There were besides fourteen similar aqueducts, with seven hundred cisterns for the public supply, and every house was furnished with separate pipes and channels. Beneath Constantinople is an ancient reservoir, three hundred and thirty-six feet long, one hundred and eighty broad, and covered with marble arches, which three hundred and thirty-six pillars support. The aqueducts of Carthage in Africa, and Segovia in Spain, as well as the cisterns of Alexandria, are amongst the most amazing monuments of civilization in existence. Of all these nations, none so much resemble the Chinese, in their mode of raising and conducting water for irrigation, as the Egyptians. To distribute the inundations of the Nile advantageously, they constructed eighty canals, some of them a hundred miles in length, and excavated three artificial lakes, Moeris, Beheira, and Mareotis. From these vast cisterns the water was raised over mounds and other obstructions by a series of buckets connected by chains, and moved by a wheel, each bucket discharging its contents as it crossed the summit of operations. Oxen were employed occasionally to work the irrigating machinery, and it is said that Archimedes borrowed from this ancient device his idea of “the cochlion or screw” for raising water. One mode employed by the Chinese resembles that already noticed as familiar to the Turks of Roumelia; and their chain-pump, the type of the English tread-mill, is identical with the Egyptian system of buckets. A third contrivance of the Chinese agriculturist, still better entitled to the claim of ingenuity, is the bamboo water-wheel, although the praise of its first invention has been claimed by others. The great moving power, called the Persian water-wheel, because that people disfigured its simplicity, is fitted in a strong-wooden frame, and, when employed for raising water, float-boards are attached to the outside of its circular rim. From the inside of the rim strong iron rods project horizontally, from each of which a square bucket is suspended by iron loops, so that, in ascending and descending with the revolutions of the wheel, all may hang perpendicularly, except those that are dipped in the water, and that one which is at the highest point. Near to the top of the frame, and at the side opposite to that on which the wheel revolves, a trough projects so far as to intercept the buckets and tilt them, compelling each to resign its contents to the trough in turn. Springs are affixed to that side of the bucket which comes in contact with the trough, by which the shock is alleviated, and the tilting made more effectual.

The Chinese water-wheel, which has been minutely described in the preceding pages,（*Vide Vol. I. p. 65. Vol. III. p. 31.） is precisely similar in its principle and effects to that used in Persia. It is formed wholly of bamboo; short pieces of leather, having one end fastened to the rod and the other to the bucket, serve to strengthen the wheel, which is then set in motion by the action of the water. The wheel is driven by the stream, and the buckets are fixed at equal intervals on the outer rim of the wheel. Not precisely horizontally, but at such an angle as allows them to dip into the stream, fill themselves, and, retaining their burden during a semi-revolution, discharge it into the trough prepared for its reception. Such wheels prevail extensively in the flat district of the Melon Islands, which is intersected by the branches of the Kan-keang just before their influx into the Poyang lake. There the coup d’œil takes in a hundred wheels at a time, each capable of raising three hundred tons of water every four and twenty hours.