=2. Gihon.=--The Parker expedition of 1909-1911 revealed by its excavations the fact that the source of the spring of Gihon is a great crack in the rock in the bottom of the valley far below the present apparent source.[230] This crack is about 16 feet long, is of great depth, and runs east and west. The western end of it just enters the mouth of the cave where the apparent source is today, but the eastern end passes out into the bed of the valley. All the water would discharge into the valley but for a wall at the eastern end of the rift, built in very ancient times, which confines the water and compels it to flow into the cave. This wall was constructed by some of the earliest inhabitants of the place. The spring thus produced is intermittent. Its flow is not ceaseless. The water breaks from the hole in the rainy season, three to five times a day; in the summer but twice a day; and after the failure of the spring rains, less than once a day. This fact indicates that the waters collect in some underground cavern from which they are drained by a siphon-like tunnel. The “troubling” of the Pool of Bethesda (John 5:4) is thought by some scholars to have been due to the action of such a siphon-like spring. =3. Cave-dwellers.=--About this spring the Parker expedition found large caves and rooms excavated in the rock, and indications that these had once been inhabited. A great deal of pre-Israelite pottery was also found around the spring. These indications seem to show that the site was inhabited for at least a thousand years before David, and perhaps for two thousand, and that its first inhabitants were cave-dwellers. One naturally thinks in this connection of the cave-dwellers of Gezer. It is possible that the first Jerusalemites belonged to the same period and were of the same race. One thinks, too, of the sacred cave and the stone altar on the next peak of the eastern ridge to the north, where the temple afterward stood, and wonders whether it may not have been the sanctuary of this early cave-dwelling race. A definite answer cannot be given to this question. One can only recognize that it may possibly be true. =4. The El-Amarna Period.=--The next knowledge we have of Jerusalem comes from the letters of Ebed-Hepa, which were written to Amenophis IV of Egypt between 1375 and 1357 B. C. At that time it was already a walled city, for Ebed-Hepa speaks of “throwing it open.”[231] The fortified city of Ebed-Hepa was, no doubt, identical with the later Jebusite city. It was situated on the eastern hill just above the spring of Gihon. Probably in the period just before this time it had, like Gezer, been surrounded by a massive wall. In connection with this fortification the rock near Gihon had been scarped (cut to a perpendicular surface) in order to increase the difficulty of scaling the wall.[232] As the wall of Gezer lasted for a thousand years, so this Egyptian wall continued to the reign of David.