The first of the great water companies was the “New River,” constructed by Sir Hugh Myddleton and opened in 1613. This was a conduit on the old pattern, but on a larger scale, and did not involve the use of pumping machinery. It brought the water of Chadwell spring in Hertfordshire, which is 110 feet above ordinance datum, to the New River head at Clerkenwell, whence it was distributed through the City. Many additional sources of water have been added to the original Chadwell spring, and many powerful pumping engines are now in use by the New River Water Company, which is still the biggest of eight metropolitan companies. The areas supplied by the different water companies may be briefly indicated. The “New River” supplies the northern part of the metropolitan area; the “East London,” which dates from 1669, supplies the north-east; the “Kent,” which dates its early beginnings from 1701, supplies the south-east. The “Southwark and Vauxhall” in its present form dates from 1845, the “Lambeth” from 1785, the “Chelsea” from 1723, the “Grand Junction” from 1811, and the “West Middlesex” from 1806. These eight companies supply about 140,000,000 gallons of water daily (about one half being from the Thames) to 668,525 houses, by means of 145 engines of 17,145 horse-power, through 4,068 miles of mains, and by the aid of a capital of £13,150,318. It is difficult for us to appreciate such a quantity as 140,000,000 gallons, but we may grasp it better if we imagine this water put into 1,400,000 water-butts, of 100 gallons each, and each 4 feet high. These butts placed end to end would reach considerably more than 1,000 miles, and that, be it remembered, is a statement of the daily water supply of this city, which is certainly well within the mark. The great fault in the situation of London was the proximity to it on every side of marshy land. The Thames, as I have stated, was formerly much wider than at present. Certain it is that Moorfields to the north was often flooded; to the immediate east and north-east was marshy ground, stretching into Essex; to the west was the low district of Thorney Island, Chelsea, and Fulham, while on the opposite bank of the Thames was the ground around Southwark and Lambeth, which was little better than a swamp, and remained unbuilt upon, except to a very slight extent, until the end of the last century. Ague is at present a rare disease in London, although one still occasionally meets with cases which are apparently due to local causes. Formerly it was a very potent cause of death, but the discovery of the use of “Jesuits’ Bark,” as Cinchona was at first called, and the gradual and continuous filling up of the soil, combined with drainage, led to its extinction. Possibly the impregnation of the soil with coal-gas may have helped to this end. MEDIÆVAL LONDON.