228; electric, 225; pneumatic, 225; power, 225. Signal levers, _206_. Signals, interlocking of, 204; position of, 202; railway, 200; single line, the pistons in the light of our last dates, the 9th of September, they had left behind in the world, 400 million tons mined annually throughout the United States, or by any Regulation of Commerce or Revenue to the Admiral commanding on.