gross rental to nearly £300,000. The number of Thames, compared with that delivered in August houses or buildings supplied by them was nearly and September, showed a marked deterioration 200,000, each of which had an average supply of in quality, the proportion of contamination with about 180 gallons, at a cost, also, on the average, of organic matter in solution having increased. The about 30s. yearly. It is not easy to ascertain the West Middlesex Company delivered the best of capital now sunk in the water-supply of the metro- the Thames waters. The sample of the Southpolis. But in 1876 the average daily supply of the wark Company's water was "slightly turbid from following eight companies-Chelsea, East London, insufficient filtration, and contained moving organGrand Junction, Kent, Lambeth, New River, South-isms." The other samples of Thames water were, wark and Lambeth, and West Middlesex-was however, clear and transparent. The water suprather more than 120,000,000 gallons, upwards of plied by the New River and the East London 60,000,000 being taken from the Thames, and Companies was much superior in quality to that the rest from other sources. The Thames supply drawn from the Thames; indeed, the New River is drawn from various points, extending up the water, in chemical purity, is said to surpass even river as far as Hampton and Ditton; the rest the deep well water delivered by the Kent Comcomes to Londoners from the River Lea, and from pany, which rises in the chalk hills about Crayford. the chalk-wells in the neighbourhood of Crayford, Chislehurst, Bromley, and Dartford, in Kent. The net-work of pipes underground to convey the water to almost every house in London, must indeed be something surprising; and it presents a striking contrast to the state of things which must have existed when the ancient conduits were the only sources of supply.

From the Report of the Examiner appointed by Government to test the purity of our water, as published by him in September, 1876, it appears that the number of miles of streets which contain mains constantly charged, and upon which hydrants for fire purposes could at once be fixed, is 667. The total number of hydrants erected at the above date was 4,211, of which 2,695 were for private purposes, 541 for street watering, 500 for public use, and 475 for Government establishments. Of the average daily supply of water in the metropolis one-fifth was delivered for other than domestic purposes. There are 398 acres of reservoirs with available capacity for the subsidence and storage of 1,041,550,000 gallons of unfiltered water, and covered reservoirs capable of storing 106,187,000 gallons of filtered water within the radius prescribed.

From an analytical report, made by Dr. Frankland, of the state of the Thames water supplied to the metropolis during the month of October, 1876, we learn that, taking unity to represent the amount of organic impurity (on this occasion) in a given volume of the Kent Company's water, the proportional amount in an equal volume of water supplied by each of the other metropolitan companies was as follows:-New River, o'9; East London, 24; West Middlesex, 28; Grand Junction, 3'3; Lambeth, 4'1; Chelsea, 4'2; and Southwark, 4'5. The water delivered by the five companies drawing their supply exclusively from the

Previous to the completion of the Main Drainage works, the system of drainage that had been adopted in London for several years gave an amount of sewerage almost equal in extent to the length of every street, lane, and alley in the metropolis. On the north side of the Thames there were about fifty main sewers, measuring upwards of a hundred miles; about twenty of equal magnitude, extending some sixty miles, were on the south side of the river. Add to these the private sewers, turnings, alleys, subways, &c., the mileage of sewerage might have been found of sufficient length to reach from London to Constantinople. Through these secret channels rolled the refuse of London, in a black, murky flood, here and there changing its temperature and its colour, as chemical dye-works, sugarbakers, tallow-melters, and slaughterers added their tributary streams to the pestiferous rolling river. About 31,650,000,000 gallons of this liquid was poured yearly into the Thames, in its course through London, and even this enormous quantity has only partially drained the great city, leaving some parts of it totally undrained for eight hours out of every twelve. The river of filth struggling through its dark channel sometimes rose to a height of five feet, but generally from two to three. The system of "flushing" the sewers, which we have already described, tends greatly to purify them; and by means of the artificial waterfalls thus secured much of the filth is swept away which would otherwise never be removed; and then, again, the sewers are better ventilated by the introduction of iron gratings, down which the daylight faintly struggles. Consequently, those whose business leads them to descend into the sewers are not now, as they formerly were, exposed to great risk of health and life.

Another important feature of "Underground London" is its "subways." These are among the latest advances which have been made in engineer

Underground London.]

THE SUBWAYS.

239

ing skill, and have resulted from the peculiar arches, similar to those employed in railway formation of some of the new streets, where, the viaducts; each arch is twenty-one feet in span, and roadway being of a higher level than formerly, forty-five feet in width, and the series is interrupted owing to its construction upon arches, an oppor- only by the three bridges which had to be erected tunity has been seized upon for their erection. on the line of the Viaduct-namely, one over Shoe Mr. Haywood, in his Report on the Holborn Lane, another over Farringdon Street, and a third Valley Improvement (1869), says: "The public over the London, Chatham, and Dover Railway. advantage resulting from the construction of sub- A line of carriage-way, upwards of ten feet in width, ways has long been acknowledged; but, at the is left throughout the whole length of these vaults, same time, it is well known that the Gas and and entrances to them are provided from FarringWater Companies showed at first considerable don Street and Shoe Lane. The vaults, which hesitation in using subways; and in the case of are immediately adjacent to Farringdon Street and those of Southwark Street, constructed under the Shoe Lane, are lighted by windows looking on to direction of the Metropolitan Board of Works, those streets, and can be used for office purposes it was not until the Board succeeded in obtaining by those having possession of them; arrangements an Act of Parliament that the respective companies are also made by which access can be given to placed their pipes in such subways." each separate compartment, arch, or vault, by forming a passage-way, beneath the subways and over the sewers, from the houses on either side of the Viaduct, so that the vaults can either be let singly or in a group, as may be expedient. Each vault is ventilated on to the surface of the roadway by iron gratings, and in the spandrils are lines of pipes, through which the water is conveyed into the sewers below.

In a previous volume we have given a general account of Holborn Viaduct, and of the improvement effected in the surrounding locality by the wholesale demolition of small and crowded houses, and the formation of new, broad, open streets; but we may here say something on a part of that mighty undertaking, which, from its being below the surface of the roadway, is passed over unseen and unthought-of by the majority of individuals. who cross over the Viaduct. The work of construction extended from Fetter Lane to Newgate Street, between which points the new surfaces of the Viaduct and roads, as compared with the former lines of thoroughfare, may be thus summarised: At Hatton Garden, and in front of the tower of St. Sepulchre's Church, the street surface is now three feet higher than formerly; at Shoe Lane it is upwards of twenty-four feet; and at Farringdon Street Bridge there is a difference of more than thirty-two feet.

From Fetter Lane to the Viaduct Circus, the width of Holborn varies from 86 feet to 107 feet; the Viaduct, from the Circus at its western end to Giltspur Street at its eastern end, is 1,285 feet long and 80 feet wide, the carriage-way being 50 feet and the two footpaths each 15 feet in width. The centre of the Viaduct is formed of a series of large arches, and on both sides are subways for gas, water, and telegraph pipes, and vaults for the use of the houses. At the western end, between Fetter Lane and the Circus, and at the eastern end, from Snow Hill to Giltspur Street, the new levels were made by filling up the ground removed from the excavations for the foundations of the Viaduct. Between Snow Hill and the Circus, the central portions of the Viaduct are formed of a series of

• See Vol. II., pp. 501-2.

The "subways" extend along the Viaduct beneath the pavement on either side, and between the larger vaults above described, and the vaults of the houses on the outer sides of the Viaduct. They are for the most part seven feet wide, and rather more than eleven feet high, and their coverings are formed of semi-circular arches in brickwork. The internal faces of the subways are of white brick, and the floors are of Yorkshire stone landings, built into the walls on each side, and laid with inclinations nearly the same as those of the surface of the Viaduct. On the sides next to the central vaults are channels cut in the landings, and at intervals of twenty-four feet are openings, covered with bell-traps, which communicate with the sewers beneath. Immediately above these trapped openings to the sewers are iron pipes, which connect with the drain-pipes in the spandrils of the central vaults, and convey the water which may leak through from the street surface into the sewer; by means of these trapped openings, the rain water which falls into the subways through the ventilators in the footways, and the water used in washing the subways, escapes into the sewers.

Owing to the difference between the old and new levels, and to the three bridges on the line of the Viaduct, the subways necessarily vary in design at about every eighty feet of their length; they are carried over the London, Chatham, and Dover Railway by an iron construction; on both sides.

KING'S CROSS UNDERGROUND STATION IN 1868. (See page 227.)

from twelve feet to fifteen feet in height; in their rear are wooden doors, which can be closed as occasion may require. There are also entrances, closed by iron doors, with open gratings over them, in Shoe Lane; and at the eastern and western ends of the Viaduct there are openings, very similar in character to those ordinarily used over the entrances to the sewers, but larger, beneath which are flights of steps for the entry of workmen; means are also provided by which pipes of large size can be lowered into or taken out of the subways.

The ventilation of the subways is effected by shafts rising from the crowns of the arches, terminating by large open gratings, let into the pavements; secondly, also, by circular flues, which start from the crowns of the arches, and, passing over

which render it sufficiently light by day for the purposes of inspection and work; the others have no daylight, excepting that obtained through the ventilating gratings in the footways, but provision is made for artificial lighting throughout the whole lines of subways by burners suspended from the crowns of the arches, and connected with the gas mains in the subways. To afford a supply of gas and water to the houses, square iron tubes are built into the walls, between the subways and the house vaults, through which the service-pipes, after being connected with the mains, are passed. The provision made in the subways for carrying the gas, water, and other pipes, consists of chairs and brackets, which are either let into the stone floor or project from the walls.

Underground London.]

Showing (1) The Subway.

(2) The Low-Level Sewer.

(3) The Metropolitan District Railway.

(4) The Pneumatic Railway.