RESISTANCE OF CURVES.
Curved track increases the resistance of trains in direct proportion to the shortness of curvature. In European railways, the character of the curves is nearly always denominated by the length of radius: in this country, a railroad curve is described as of so many degrees. The degree of a curve is determined by the angle subtended at its center by a chord of 100 feet. To those who think of a curve by its radius, it may be well to explain that a curve of one degree has a radius of 5,370 feet, and the radius of any curve can be ascertained by dividing these figures by the number of degrees.