According to the Scientific American (through whose courtesy the accompanying cuts are reproduced), the water flows through a six-inch steel casing into a “stonecatcher" (illustrated herewith), which arrests pebbles (some weighing twenty-two and one-half pounds), small boulders, and stones, which are shot out with force enough to damage the casing and machinery.

I note that in a recent New Scientist some twunt was advocating the use of C02 pressure washers and acidic/caustic cleaning foams instead of the usual disinfectant approach.

[…]an account of the gums ammoniac of Morocco and the Cyrenaica. The latter, which is the gum ammoniac described by Dioscorides, is referred to Ferula marmarica.

Chaucer for years before the Prologue to LGW had been writing heroic couplets at the close of each of his rhymes royal.