deceased was employed by a firm of contractors erecting a new coal-washer at the colliery; on this day work had been stopped on account of heavy rain; a piece of wire rope had been left dangling from part of the structure, and as it was in a position likely to become entangled with railway wagons in motion on the rails below, deceased proceeded to remove it; he climbed up a ladder to a height of 18 feet, and in stepping off the ladder on to a concrete floor at that point, he slipped and fell to the ground; he was picked up unconscious and died four hours later