The other conspicuous building is a round castellated structure that might well pass for a Norman keep, but is, in fact, the water tower of Ely, supporting a huge tank into which water is forced from springs at Isleham some seven miles distant.[231] The inhabitants of the city have good reason to be thankful for this water supply; not a hundred years ago the natural springs on the spot were so inadequate for their use that most of the water for brewing and washing had to be brought up from the river, slung in a pair of leather bags on horseback, an arrangement manifestly inconvenient, "though providing," as the historian adds, "a comfortable subsistence for many industrious poor." Let us hope that these poor folk did not bear a grudge against Dean Peacock, to whose zeal the waterworks of Ely are mainly due. [Footnote 231: See p. 183.] One of the chief industries of Ely is the making of jam, for which the rich fruit-growing fields in the neighbourhood supply the material. And if we follow the main street down to the wharf on the river Ouse we shall see in the piles of willow wands that lie ready stripped on its banks, evidence of a much older industry still carried on here. This is the basket-making, for the which the fenland districts of Britain were famed even before the Romans reached the country. Posidonius, the Rhodian geographer under whom Cicero studied, and who himself visited our island about 100 B.C., mentions "British baskets" as exported for use on the Continent. A century later Strabo tells us of their extensive home use, for storing corn, and Martial, in the next generation, gives us the very word, which was adopted into the Latin from the Celtic original (still used in Welsh), as it has since been adopted into English. In sending a present to a lady he alludes to it as: "A basket rude, from painted Britons come." ("Barbara de pictis venio _bascauda_ Britannis.") The withies of which the baskets are made were at first, doubtless, the shoots of the willows found growing wild along the streams. Now they are cut from carefully tended osier-beds, small enclosed areas which are periodically flooded, where the willows are regularly cultivated with a view to the production of long shoots suitable for this industry. "They are regularly cut, peeled, and seasoned and afford employment to large numbers of people."[232] Nor is the making of baskets the only purpose for which willows may be profitably cultivated; for, as Fuller says:--"This tree delighteth in moist places and is triumphant in the Isle of Ely, where the roots strengthen the banks and the lop affords fuel for the fire. It groweth incredibly fast; it being a by-word in this county that the profit by willows will buy the owner a horse before other trees will pay for his saddle." [Footnote 232: Hughes. _County Geography of Cambs_, p. 98.]