Evidence exists that, 24000 years ago certain Hebrew engineers executed the same kind of work as that of the Simplon tunnel, though perhaps on a smaller scale, says the "Engineer." Owing to the bad state of the water supply of Jerusalem, the king ordered a reservoir to be made at the gates of the city, to which water was brought from various springs.

Recent explorations have enabled this predecessor of the Simplon tunnel to be identified, and it is said to be the Shiloh tunnel, by means of which water was brought down from a source to the east of Jerusalem and poured into the pool of Siloam. This conduit is 360 yards long, and the distance, as a bird flies, between the two mouths of the tunnel is also only 360 yards.

Work was commenced at both ends of the tunnel and the direction was altered several times. The floor of the tunnel is finished with great care, and the workings are from 1.9 feet to 1 yard in width and from 3 to 9 feet high. In the light of modern engineering ing science it may be asked how these old-time engineers gauged their direction and recognized and remi-died their errors in alignment. What tools did they use in executing this work which has remained without equal for 2400 years?