But when this source of supply evidently was becoming overtaxed, another was found in the underlying chalk. This rock absorbs water rapidly, but parts with it very slowly. Professor Prestwich found by experiment that a slab of chalk measuring 63 cubic inches drank up 26 cubic inches of water (all it could hold) in a quarter of an hour; yet when left to drain for twelve hours it parted with only one-tenth of a cubic inch.[12] So that an ordinary well is useless. But the upper part of the chalk, generally to a depth of rather more than 300 feet, is traversed by fissures, and these are full of water. So a bore-hole is carried down till one of them is struck, and they are so abundant that failures are rare. In this way the water-supply of London is materially augmented.
This source also—at any rate in the immediate neighbourhood of London—is becoming overtaxed, so an effort has been made to obtain water from yet greater depths. Below the chalk is an impervious clay (Gault), and beneath this comes a brownish sand, followed by some other beds not quite so porous (called the Lower Greensand), which are succeeded by thick clays. These sandy rocks crop out at the surface to the north of London in Buckinghamshire and Bedfordshire, and to the south in Surrey and Kent. So they reasonably might be expected to pass beneath the metropolis, to be saturated with water, and to yield a large supply as they do at Paris, the geological position of which bears a considerable resemblance to that of London. Bore-holes have been put down in search of these sands at Kentish Town, Meux’s Brewery (Tottenham Court Road), Richmond, Streatham, and Crossness. They have also been sunk beyond the metropolitan area at Ware, Cheshunt, Harwich, and Chatham. At the last place the Lower Greensand is only about 40 feet thick, instead of 400 feet as it is south of the North Downs.[13] It was expected to occur under London at a depth of about 1000 feet in round numbers, but in every case it was found to be either wholly absent or so thin as to be worthless. This is true even so far away as Ware and Harwich on the northern side, and perhaps as Croydon on the southern. In the days when this Lower Greensand, and even a considerable thickness of strata which elsewhere comes beneath it, were deposited, a large island or peninsula composed of much older rocks must have risen above the sea in the region over which London and all its environs now stand. So there is no hope of increasing the supply of water from any beds older than the upper part of the chalk. But a good deal more may be obtained from this rock, if it be tapped at longer distances from the metropolis. To this process, however, there are two objections: one, that the number of wells and of conduits which will be required in order to collect the water will probably make it a rather costly source of supply; the other, that if large demands be made on the water stored up beneath the chalk hills, the level of the surface of saturation in this rock will be appreciably lowered, many springs will be dried up, and the streams will be seriously diminished, which will greatly injure thousands of acres of water-meadows and many important industries. Large sums would have to be paid as compensation, and this would add greatly to the cost of any scheme. It is doubtful whether more water ought to be withdrawn from the Thames and its tributaries; and rivers which flow through a thickly populated country can hardly be regarded as safe from sewage contamination. It is therefore not improbable that, within a few years, the metropolis will have to follow the example of Liverpool and of Manchester, and seek another source of water-supply at a yet greater distance than has been done by those cities.
T. G. Bonney.
CHAPTER II
THE SITE
It is due to the respect with which all writers upon London must regard the first surveyor and the collector of its traditions and histories that we should quote his words as to the origin and foundation of the City. He says (Strype’sStow, vol. i. book i.):—
“As the Roman Writers, to glorify the City of Rome, drew the Original thereof from Gods, and Demi-gods, so Geoffrey of Monmouth, the Welsh historian, deduceth the Foundation of this famous City of London, for the greater Glory thereof, and Emulation of Rome, from the very same original. For he reporteth, that Brute, lineally descended from the Demi-god Eneas, the son of Venus, Daughter of Jupiter, about the Year of the World 2855, and 1108 before the Nativity of Christ, builded the City near unto the River now called Thames, and named it Troynovant, or Trenovant. But herein, as Livy, the most famous Historiographer of the Romans, writeth, ‘Antiquity is pardonable, and hath an especial Privilege, by interlacing Divine Matters with Human, to make the first Foundations of Cities more honourable, more Sacred, and as it were of greater Majesty.’
This Tradition concerning the ancient Foundation of the City by Brute, was of such Credit, that it is asserted in an ancient Tract, preserved in the Archives of the Chamber of London; which is transcribed into the Liber Albus, and long before that by Horn, in his old Book of Laws and Customs, called Liber Horn. And a copy of this Tract was drawn out of the City Books by the Mayor and Aldermen’s special Order, and sent to King Henry the VI., in the Seventh year of his reign; which Copy yet remains among the Records of the Tower. The Tract is as followeth:—
‘Inter Nobiles Urbes Orbis, etc. 1. Among the noble Cities of the World which Fame cries up, the City of London, the only Seat of the Realm of England, is the principal, which widely spreads abroad the Rumour of its Name. It is happy for the Wholesomeness of the Air, for the Christian religion, for its most worthy Liberty, and most ancient Foundation. For according to the Credit of Chronicles, it is considerably older than Rome: and it is stated by the same Trojan Author that it was built by Brute, after the Likeness of Great Troy, before that built by Romulus and Remus. Whence to this Day it useth and enjoyeth the ancient City Troy’s Liberties, Rights, and Customs. For it hath a Senatorial Dignity and Lesser Magistrates. And it hath Annual Sheriffs instead of Consuls. For whosoever repair thither, of whatsoever condition they be, whether Free or Servants, they obtain there the refuge of Defence and Freedom. Almost all the Bishops, Abbots, and Nobles of England are as it were Citizens and Freemen of this City, having their noble Inns here.’
These and many more matters of remark, worthy to be remembered, concerning this most noble City, remain in a very old Book, called Recordatorium Civitatis; and in the Book called Speculum.