Jotham (about 745 B. C.) is the first Hebrew king who is said to have built a wall on Ophel,[127] though he may merely have made it stronger, as it possibly formed part of Solomon’s wall round Jerusalem, including the Temple and the palace. He was no doubt alarmed at the progress which was then being made by the Assyrians in the conquest of Syria. His successor, Ahaz, was attacked by Pekah of Israel and Rezin of Damascus some ten years later, though they failed to take the city.[128] We have some details of interest as to the water-supply of Jerusalem at this time, before the great works of Hezekiah were carried out[129]; for, in connection with this attack, Isaiah notices the “conduit of the upper pool,” and the “waters of Shiloah that go secretly”; he speaks also rather later of the “collection of the waters of the lower pool,” and of the “place where the waters of the old pool flowed together between the two walls.” Whether we are to understand that the Siloam tunnel was begun as early as the time of Ahaz, or that the older conduit--already described--was then made, there is apparently no connection between the secret water-supply of Shiloah and the other pools noticed by Isaiah. It is certain that the Upper Pool must have been on the west side of the city, since it was there that the Assyrians appeared in 703 B. C., and the site of the Assyrian camp was still pointed out as late as 70 A. D. in this direction.[130] The conduit from this pool to the “lower pool” was no doubt that which also existed in the time of Herod, and which still carries water to the so-called “Pool of the Bath” or “of Hezekiah.” The last named may very well be regarded as the “Old Pool,” being “between the two walls”--that is to say, inside the wall of the lower city and outside that of the upper city. This important reservoir, which was “old” even in the time of Isaiah, thus seems to have been possibly of the Jebusite age. The work of Ahaz consisted in forming an upper reservoir (now called _Birket Mâmilla_) to supply the old pool by a conduit leading into the city.