The engine gives off fully 15-horse power on the steepest gradient, the total traction weight being 8½ to 9 tons; it is worked with an average steam pressure of 5 atmospheres, and has cylinders of 180 mm. diameter and 220 mm. stroke, cog wheel-gear of 2 to 3, and driving wheels of 700 mm. diameter.

It was a primitive mill, which superseded the still more primitive hand-mill, or quern; and I myself have seen it at work in the Shetland Islands, and even the north of Scotland, though it is now done away with even there, still more farther south, and its place supplied and its work done by overshot and under-shot wheel-gear, and improved machinery attached, of less or more complexity.

She sat down in the moon-path on the water, courtesying with a flourish of pride impressive enough had not the wheel-gear sniggered mockingly in its box. Harvey laughed aloud. "Why, it's just as if she was alive," he said. "She's as stiddy as a haouse an' as dry as a herrin'," said Dan enthusiastically, as he was slung across the deck in a batter of spray.