"The scarcity of running water led to the digging of wells, and we find them mentioned in the earliest books of the Bible. There are many wells of this sort in the country, and some of them are thousands of years old. We read in Genesis of the wells that were dug by Abraham and his descendants, where the flocks were watered. The wells of Beersheba which were made by the servants of Isaac (Gen. xxvi. 32, 33) can be seen to-day, and the stone watering-troughs from which the flocks drank are where they have stood for thousands of years. In some of the ancient wells there are stone steps leading down to the water, while in others the water was drawn to the surface by means of buckets at the ends of ropes. The ropes made deep channels in the stone where they rubbed against it. Some of the wells have been dry for hundreds of years, but the stones that surround them remain undisturbed. [Illustration: INTERIOR OF A CISTERN.] "Where there are no running streams or springs, and the nature of the ground does not favor the digging of wells, the people rely upon cisterns to supply their wants. A cistern is simply a large excavation in the earth or rock; if in the former, it is lined with stone and cement to make it water-proof, but if it is hewn in the solid rock no such precaution is necessary. Water is collected here during the rainy season and treasured up for use in the dry summer. Some of the cisterns are of great extent, and will hold water sufficient for great numbers of people during several months. They are found all through the country; and even where there is a stream of water the whole year round it is often the custom to keep cisterns filled with water, to guard against an unusual drought. Some of the cities of the East have vast cisterns beneath them, and if you ever go to Constantinople you will see the cistern of 'The Thousand and One Pillars,' which gets its name from the number of columns that support the roof. [Illustration: CISTERN UNDER THE TEMPLE OF JERUSALEM.] "There is a cistern under the Temple of Jerusalem," continued the Doctor, "that was hewn from the solid rock. Portions of the rock were left standing to form a support for the temple, and they have performed their work so well that no part has ever given way." As the Doctor paused it was announced that the horses were ready, and in a few minutes the cavalcade was again in motion. A tower on the right of the road attracted the attention of the youths. The Doctor told them it was the station of a watchman, and that it was his duty to guard the fields and vineyards from depredations by men or beasts, and to preserve order along the road. "There are eighteen of these towers," said he, "between Jaffa and Jerusalem, about two miles apart, and the men in them are supposed to have control of the road, and to protect travellers from danger. The watch-tower is an institution of the East, and its use dates from a very early period."