On a level with the base of the tank, projecting from the exterior of the tower, and carried on strong and elegant cast-iron brackets, is the gallery six feet in width, from the outer edge of which, on light iron columns, is carried the many-gabled conical Paxton roof which covers the tower. The total height of these stupendous edifices, from the ground line to the top ornaments on the roof, is 284 feet. From the same ground line to the floor of the projecting gallery is 214 feet, involving to the persevering visitor an ascent of no fewer than 400 steps, with only ten landings or rests on the floors previously mentioned. The reward in the prospect afforded will, however, amply repay the toil incurred, embracing as it does an horizon including part of six counties--viz., Middlesex, Kent, Essex, Bedfordshire, and Bucks--and including a panorama possessing, amongst other objects of interest, the Towers of London and Windsor, the woodlands of Essex, and the Downs of Epsom. The vision of the visitor from this height is also lifted over the grand plateau, or ridge, which separates the great lake with its antediluvian animals from the rest of the garden. These magnificent towers, each of which contains 800 tons of iron, were designed by Mr. Brunel. From the above simple statement it will be seen, that the arrangements for supplying the fountains with water are at once simple, complete, and based upon the most economical principles. The engine power employed is that of three hundred and twenty horses; the water itself is conveyed to and from the reservoirs in pipes varying from three feet to one inch in diameter; and the total weight of piping may be set down at 4000 tons, its length, roughly estimated, at ten miles. THE ARTESIAN WELL, AND THE WATER SUPPLY. In July, 1852, the supply of water for the fountains and other great works in connexion with the Crystal Palace, first seriously engaged the attention of the Directors. Various proposals were made, and suggestions offered: some were at once rejected; others, although not free from difficulties, were taken into consideration. The most feasible of these was that which involved the extension to Sydenham of the pipes of one of the nearest London water-work companies,--a measure that would at once secure a sufficient supply of tolerably good water. Against the proposition for sinking a well on the grounds, it was urged that the neighbourhood is almost destitute of water; that wells already excavated to the depth of two hundred feet had yielded but a small supply; and that even if a sufficient supply could be secured by digging, the water obtained could never be raised to the top of the hill. 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.