Accordingly, when the front “driver” of the second engine was on the bridge, I raised my hand to Salem. There followed a terrific roar, and the line vanished from sight behind a spouting column of black dust and smoke a hundred feet high and wide. Out of the darkness came shattering crashes and long, loud metallic clangings of ripped steel, with many lumps of iron and plate; while one entire wheel of a locomotive whirled up suddenly black out of the cloud against the sky, and sailed musically over our heads to fall slowly and heavily into the desert behind. Except for the flight of these, there succeeded a deathly silence, with no cry of men or rifle-shot, as the now-grey mist of the explosion drifted from the line towards us, and over our ridge until it was lost in the hills.