the work got difficult, as the débris consisted entirely of large chippings, the scarp evidently having been quarried away at the top at this point. Moreover, we were very near the cemetery wall, under which we did not care to tunnel. I, however, sunk a shaft in the school garden, beyond the cemetery, about 200 feet from E, and found a scarp almost in a line with E—F; that it is not exactly in a line does not prevent its being a true continuation (the difference was only 4 degrees), as we can see in the main scarp that the direction alters slightly from time to time. We followed this garden scarp (including a turning) for 22 feet, the rock then continued with a steep face, but unscarped. It was here naturally so perpendicular that the original engineers seem to have thought it unnecessary to work it.
We will now return to H, whence we followed the scarp with its various turnings to the south-east. The angle at J is beautifully worked. Between J and K, along the face of the scarp, there runs a sort of channel a couple of inches deep, evidently for collecting water. At K the top of the scarp appeared in the tunnel, and we sunk a shaft to ascertain the depth, which we found to be 15 feet. At K there is a sudden drop, so that the top of the scarp along K—L is 4 feet lower than the point K. From M to L the face is not quite regular. At the corner, M, there is another sudden drop. From M to N (as seen in the elevation[1]) the top of the scarp descends regularly and gradually, following, it is interesting to note, the slope of the surface of the ground 28 feet above. Our gallery followed the same slope, each box or frame being set 3 or 4 inches lower than the one behind it. At N we lost the clue. The scarp appeared to turn to the left. We were following it along its to]), and had not yet found the true depth at M. Accordingly we took the superficial turning at N for the true turning, and our troubles began. When the right clue is lost tunneling becomes dangerous work. When you open up in several directions from the same point, the fear of caving in becomes great. We were obliged twice to leave the scarp, and to drive a tunnel parallel to the direction required, returning to the scarp further on. We spent much time and trouble in shoring up, and I must say that Yusif managed most admirably and safely. We followed the line from N to V (see dotted line on plan), disgusted at the lowness of the scarp, at its arbitrary turnings, and at its evident resemblance to a quarry. I was much puzzled, for the fine lines from E to N seemed to preclude the quarry idea, and yet we seemed to be following a continuous line. Moreover, we were much troubled by large stones in the tunnels, which had to be broken up very carefully before the work could go on. The men in this tunnel spent almost a month in following these false clues.
In the meantime, having a gang of men to spare one day, I set them to find the true depth of the scarp at the point M, and this turned out to be the solution of our difficulties. To my delight, this was proved to be
- ↑ The elevations and sections referred to by Dr. Bliss are reserved for future publication.
