Finally, after a couple of days of skirting and dodging, the Doctor gave the word and they turned north and began straightforwardly ascending into what had plainly become a mountain range. At first this was a grassy rampart. Then strange dark hummocks began to pock the fields. At the same time, they began frequently to see pairs of men turning windlasses, like the ones mounted above wells, but this equipment was stouter and grimier, and it brought up not buckets of water but iron baskets filled with black rock. Jack and Eliza had seen it before at Joachimsthal and knew that the dark mounds were the fœces left behind when the metal (copper here) had been smelted out of the ore. Germans called it schlock. When they were wet with rain (which was frequently, now), the schlock-heaps glistened and gave back light tinged blue or purple. Men collected the ore from the hand-haspels (as the winches were called) into wheelbarrows and staggered behind them, among schlock-piles, to smoking furnaces tended and stirred by coal-smeared men.