Acting, however, upon sound advice, and after due consideration, the company commenced the sinking of an artesian well at the foot of the hill on which the Palace stands, and after proceeding to a depth of 250 feet, their efforts were rewarded.
In the present case, the water which appears in the well comes from a reservoir lying between the London clay and the greensand as its upper and lower envelopes. This reservoir is supplied by rain-water, which, percolating the London clay, sand, and chalk, and finding an impediment to its downward progress on reaching the greensand, flows into the space between the hard clay and greensand, as into a cistern. The process by which the reservoir is supplied is continuous, the water finding its way down to it as if by a series of small tubes, and pressing against the lower surface of the clay with a force which, if unresisted, would raise it to the level from which it descended. When the clay is pierced by the augur it is evident that this force is free to act, the resistance of the clay at the point where it is pierced being removed, and accordingly the water rises in the bore to the level from which it is supplied, and will continue to do so as long as the percolation lasts. The chief difficulty to be overcome was the great thickness of the substratum of chalk, which extends, probably, to a depth of about 1000 feet. The well, now completed, is a brick shaft 81⁄2 feet in diameter, 247 feet deep, from whence an Artesian bore descends 328 feet, making the entire depth 575 feet. It is situated at the bottom of the Garden, near the Cricket Ground.
An abundant supply of water having been brought to the foot of the hill from the well, and the supplies of a neighbouring water-company, it was necessary not only to raise it to the top, on a level with the building, but also to elevate it to a sufficient height for obtaining the requisite pressure for fountains to throw up water to heights varying from 5 to 280 feet. The following is a brief outline of the arrangements by which these objects are effected:—
Three reservoirs have been formed at different levels in the grounds, the lowest one being on the same level as the largest basins placed nearly at the base of the hill; the second or intermediate reservoir is higher up, and in a line with the basin in the central walk; whilst the third or upper reservoir stands on the top of the hill immediately adjoining the north end of the building. Next to the Artesian Well, an engine is placed which raises the water required to be permanently maintained in the reservoirs and in the basins of the fountains, and which supply or keep up the water that is lost by waste and evaporation.
The reservoir on the summit of the hill contains the water required for the use of the building, and for the fountains throughout the grounds. Close to this reservoir is an engine-house, containing the steam-engines that raise part of the water into two large tanks erected on columns at the north end of the building close to the junction of the Sydenham and Dulwich roads. The columns, twenty-four in number, are of hollowed cast-iron, one foot in diameter. The central column, which is two feet in diameter, supporting a portion of the superincumbent weight, and making up the number, twenty-five, is the water-pipe, by which the tank is fed, and which forms also the conduit to the fountains in the building, and on the terraces. These two distinct actions of filling the tank and working the fountains proceed simultaneously through the same pipe. On the top of these columns are massive girders which support the plates, forming the bottom of the tank. The height from the stone curb of the reservoir to the bottom of the tank is 65 feet; the tanks are each 47 feet square by 15 feet deep, and capable of containing 207,000 gallons or about 900 tons of water. They supply also the water required in the building for the plants and kitchens, and charge the pipes provided against casualties from fire. The vast residue of the water in the great upper reservoir, in consequence of the sloping character of the ground, does not need any help from the engines, but flows direct to fountains on a lower level, and plays smaller jets. Through the same convenience, the waste water from the upper fountains is used a second time in the lower fountains.
The central or intermediate reservoir collects the waste water from the displays which take place on ordinary days, and which include all the fountains, save the two largest, and the cascades. Attached to this reservoir are also engines which pump the water back to the upper reservoir. The lowest reservoir collects similarly the waste water from the displays which take place in the two largest fountains on the days of great exhibition, and its engines return the water at once to the top level.
THE FOUNTAINS.
The great system of fountains in the grounds of the Crystal Palace, though the most stupendous that the world has ever seen, is designed with an unity which greatly enhances, or rather fully displays, its unrivalled magnificence. The whole system is divided into two series, the upper and the lower. The upper series, which consists of the six basins adorning the long extent of the second terrace, with the great circular fountain in the centre, and the smaller ones on either side of it, in all, nine fountains, constitutes the display on ordinary occasions. Beyond these, as we advance down the central path, are the iron Water Temples, from which the water rushes down a series of twelve cascades, extending for a distance of 600 feet, till it falls over the stone arcade in the great fountain basins, forming a glittering cataract 120 feet broad, with a fall of thirty feet. The Water Temples with their cascades and falls, and the two great fountains into the basins of which they discharge, constitute the lower series, which is played only on grand occasions; but all are part of one design, and each one ministers to its completeness.
Unlike most similar works, sculpture has not been used to enhance or obtain the effect desired. Under any circumstances, water, when thrown high into the air, assumes a graceful and beautiful appearance; no ungentle curves or distortions of form mar its expression of a natural beauty, which, though it may be the roaring grandeur of a mighty stream, or the gentle grace of the smallest jet, bears with it an unspeakable charm. In the Crystal Palace Fountains the designs are carried out by the water alone, and the sculptural ornamentation is confined to the margins of the basins, and, down the sides of the cascades, to some small ornamental bronze fountains of secondary importance.
The first six fountains of the upper series which ornament the Italian Garden on the second terrace throw their highest jets to the height of 90 feet, the lower jets form graceful designs round the bases of these columns of water, and in other parts of the basins. It is so arranged that the waste water from these basins is again used for the lowest jets of the fountains which lie between these and the Water Temples, a rapid descent in the ground giving sufficient pressure for this purpose; the same is the case with the water flowing from these again, as it is once more used for the lower water designs in the great basins.