The work was begun with an auger of about a foot in diameter, and the borings showed successively the alluvial soil and subsoil, and the tertiary sands, gravels, clays, lignite, &c., until the chalk was reached. The work was then carried on regularly through the hard upper chalk down to the lower chalk with green grains, the dimension of the auger being reduced at 500 feet to a nine-inch, and at 1,300 feet to a six-inch aperture. When the calculated depth of 1,500 feet had been reached, and as yet no result appeared, the Government began to be disheartened. Still, upon the urgent representations of the celebrated Arago, the sinking was continued, until at length, at the depth of 1,800 feet, the auger, after a violent shock which made the ground tremble, suddenly turned without an effort. ‘Either the auger is broken, or we have gained our end,’ exclaimed the director of the work; and a few moments after, a large column of water gushed out of the orifice. It took more than seven years to accomplish this grand work (1833–41), which was retarded by numberless difficulties and accidents. About half- a-million gallons of perfectly limpid water of a temperature of 82° Fahr. are daily supplied by the Puits de Grenelle, and amply repay its cost (362,432 fr. 65 centimes = 14,500_l._). The high temperature of Artesian springs, when rising from considerable depths, has been turned to various practical uses. Thus, near Canstadt, in Wurtemberg, several mills are kept in work, during the severest cold of winter, by means of the warm water of Artesian wells which has been turned into the mill-ponds, and at Heilbronn several proprietors save the expense of fuel by leading Artesian water in pipes through their green-houses. In some localities the pure and constantly temperate Artesian waters are made use of for the cultivation of cress. The vigorous growth of this salutary herb in the beds of rivulets, where natural springs gush forth, gave the idea of this application, which is so profitable that the cress nurseries of Erfurt yield a produce of 12,000_l_. a year. Fish ponds have also been improved by such warm springs being passed through them. Among the localities benefited by the boring of Artesian wells, Venice deserves to be particularly noticed. Formerly the City of the Doges had no other supply of water but that which was conveyed by boats from the Brenta, or obtained from the rain collected in cisterns. Hence the joy of the inhabitants may be imagined, when, in 1846, an Artesian boring in the Piazza San Paolo began to disgorge its water at the rate of forty gallons per minute, and when other undertakings of the same kind proved equally successful.