The principal fountain described above, then, was completely finished in marble by Tribolo, and carried to the finest and greatest perfection that could be desired in a work of this kind. Wherefore I believe that it may be said with truth that it is the most beautiful fountain, the richest, the best proportioned, and the most pleasing that has ever been made, for the reason that in the figures, in the vases, in the tazze, and, in short, throughout the whole work, are proofs of extraordinary diligence and industry. After this, having made the model of the above-mentioned statue of AEsculapius, Tribolo began to execute it in marble, but, being hindered by other things, he did not finish that figure, which was completed afterwards by the sculptor Antonio di Gino, his disciple. [Illustration: THE HERCULES FOUNTAIN (_After =Niccolo [Tribolo]=. Florence: Villa Reale di Castello_)] On the side towards the east, in a little lawn without the garden, Tribolo arranged an oak in a most ingenious manner, for, besides the circumstance that it is so thickly covered both above and all around with ivy intertwined among the branches, that it has the appearance of a very dense grove, one can climb up it by a convenient staircase of wood similarly covered with ivy, at the top of which, in the middle of the oak, there is a square chamber surrounded by seats, the backs of which are all of living verdure, and in the centre is a little table of marble with a vase of variegated marble in the middle, from which, through a pipe, there flows and spurts into the air a strong jet of water, which, after falling, runs away through another pipe. These pipes mount upwards from the foot of the oak so well hidden by the ivy, that nothing is seen of them, and the water can be turned on or off at pleasure by means of certain keys; nor is it possible to describe in full in how many ways that water of the oak can be turned on, in order to drench anyone at pleasure with various instruments of copper, not to mention that with the same instruments one can cause the water to produce various sounds and whistlings. Finally, all these waters, after having served so many different purposes, and supplied so many fountains, are collected together, and flow into the two fish-ponds that are without the palace, at the beginning of the avenue, and thence to other uses of the villa.