The hills are mostly of limestone, and lie in long parallel ranges, due east and west, with steep crags and precipices on the crests, and long tree-clad slopes below. They gradually lose their elevation as they approach the Mosul plain; but even at the last stand up over that endless level with a startling abruptness. The rivers, true to their habit in this land of contradictions, burst clean through these ranges in their southern course, though they naturally receive tributaries in each one of the parallels. Good coal lies under much of this country; the writer having actually seen one six-foot seam that crops out at four several points along a line of sixty miles, and is probably continuous in other directions also. It is of course quite unworked at present. Turkish political economy teaches that for so long as the coal is there, it is safe, and a solid national asset. If, however, you dig it up and burn it, it is gone and cannot be replaced. Besides, mining concessions, or anything else likely to bring in the foreigner, are anathema to the Ottoman and are never granted if they can possibly be avoided. [Illustration: TRAVELLING IN LOWER TKHUMA. No. 14] The principal landmark in the Sapna valley is the town of Amadia; a city set on a hill indeed--perched on the summit of a great isolated knoll which juts out from the mountains behind it like a bastion from the curtain of a fortress. The slopes of this knoll are surmounted by a cresting of limestone precipice, so even and continuous round the whole circuit of the level summit that it looks from a little distance like a prodigious artificial wall. The place must have been a notable stronghold even in Assyrian days, as a much battered bas-relief on the rock face by the main gate testifies: but the ramparts which Nature has given it were always sufficient protection; and, except at the two entrance gateways, no further defences were required. It is now but a group of mean hovels, no more than a rather large village; but it ranks in the Sapna valley as the metropolis of the country-side.