length, and 178 high divided into three stages with numerous and long tunnels, lighted and ventilated from the depth of 250 feet, by conical shafts of 50 feet diameter at bottom, and four feet at top, and others of inferior note, we select for more special description and detail, the chief water works of England, and of France, and the magnificent aqueduct of Lisbon. London, like Rome, was already a large and populous city, before its supply of water was copious or convenient. In the reign of Henry II., about the middle of the twelfth century, the inhabitants relied on the Thames, or wells in the city, and on springs rising in the elevated grounds,

north and west of the city. Fitz Stephens thus refers to this last fact in his " Description of London in the reign of Henry II." " Round the city again, and towards the north, arise certain excellent springs at a small distance, whose waters are sweet, salubrious, and clear, and whose Runnels murmur o'er the shining stones.

Among them, Holywell, Clerkenwell, and St. Clement's well, may be esteemed the principal, as most frequented, both by scholars from the schools, and youth from the city. when in a summer's evening they are disposed to take an airing." The antiquarian, Stowe, who published his " Survey of London," in the reign of Queen Elizabeth, gives this account of the source and supply of water to the city :

" Anciently, until the Conqueror's time, and for 200 years afterwards, the citie of London was watered (beside the famous river of the Thames on the south part,) with the river of Welsj as it was then called, on the west which water is called Wallbrooke, running ;