Extensive coverage of every aspect other than the history of railroading. Begins with basic elements, the track and its behaviour, the gauges, the laying of the line, bridges, tunnels, wires, signals. Then on to the story of steam, oil, gas, power; of passenger and freight cars; of checkups along the line; of terminals, supplies, speed gains, modernizing of service, on to railroads in war. Behind the scenes in the flow of commerce, transportation, organization.