Yet the fact that a size limit could be reached and apparently was reached, was still no sign that the limits of steam locomotive efficiency had even been approached. Because the methods by which these limits may be extended, apparently almost indefinitely, are so complex and withal so fascinating, I am taking them up in a separate chapter of this book. This chapter and the one that follows it are the record of the achievements and the possibilities of the electric locomotive, whether as a separate unit or merely as a compact bundle of energy stowed away in the trucks of a passenger or freight-car. That locomotive shall receive our first consideration. Now despite all the improvements that we shall see have been made upon him, the American steam locomotive of to-day seemingly remains a laggard. In the days when his fuel was both plentiful and comparatively cheap one might merely say that he was extravagant and let it go at that. But now when coal if not scarcer is far more expensive his extravagance has become totally unwarranted. In 1918, the most recent year for which the figures are available, our steam locomotive consumed 163,000,000 tons of coal in addition to 45,700,000 barrels of oil. Reducing these last to their coal equivalent, we have a total fuel consumption expressed in terms of coal of 176,000,000. And when we measure that consumption alongside the freight carried--1918 was one of the record years of our American railroads--it will be seen that for every thousand tons of freight that they moved one mile they burned 290 pounds of coal. Through any modern steam-generating electric station--the figures taken from the modern power-houses of the few steam railroads that already have been progressive enough to install electric motive-power--an even hundred pounds of coal may easily move more than 1600 tons of freight one mile--in the accurate phrasing of the railroaders themselves, 1600 ton-miles. In other words the same freight traffic moved by electricity through steam power houses would have required but a little over fifty million tons of coal. From 120,000,000 to 130,000,000 tons of coal would have been saved--a saving roughly expressed in money at between three-quarters of a billion and a billion dollars, which of itself would be a 4 or 5 per cent. dividend upon the total capitalization of our American railroads.