According to the diagrams of several roads in regard to the renewal of rails, the least wear takes place, as a general rule, upon the tangents away from stations, increasing on the gradient tangents. On curves, the rate of wear is even greater than on the gradient tangents, and greatest where curve-gradients occur.

The wear on rails on curves is of two classes: 1st. The ordinary wear on the surface of the rail, augmented by longitudinal and transverse slipping of the wheels. 2d. A severe abrasion or cutting on the inner head of the outside rail. (See Figs. 8, 9, 10 and 11.)

The wear on different roads is not the same, because different systems of track-laying and different joint-fastenings are employed. I have designed the rail-sections, to which attention is here called,

in series of three each, to provide for this unequal wear on the various portions of the road. The rails of each series are designated by letter, and the weight of each section, increasing by 5 pounds each, is further designated by a prefix to its letter indicating its rank in the series, viz.: the first section of the series is called "light," the

second one "medium," and the third "heavy." The respective designations will be rolled on their webs in manufacture.

The light sections of series A and B are made especially stiff for the weight of metal used, having also broad heads, well supported by large curves, giving a far greater wearing capacity than might at first seem likely when comparing them with rails having deeper but

not so well-supported heads. The medium section of the series has a slight increase of width of head, but far greater wearing capacity, i.e., a greater amount of metal to lose per yard to provide for the increased severity of their location under the same tonnage. The stiffness of the section is also increased to sustain the service better, reduce the wear upon the ties, and equalize it more nearly with the rate upon the levels.

This will be far more important where "treated" ties are used, and also with metal ties, which will come into use on our large lines within a short time.

The still stiffer- and broader-headed "heavy" section for the curves provides a very effective method for reducing the now excessive abrasion of the inner head of the outside rail of the common type on curves. See Figs. 8 and 9 of a rail of the common type, showing severe abrasion; Figs. 10 and 11, ordinary abrasion.

This statement of the fact of reduced abrasion is not only based on a theoretical consideration of the case, but a large experience in observing the results of such a system in service.

Fig. 12 shows the curtate cycloids described by four selected points in the flange of a wheel rolling on the rails. When the axle is at right angles to the rails on tangents, or radial to the rails on curves, the abrasion is slight. If, however, the axle is inclined to the rail, so that the flange of the wheel touches the rail forward of a perpendicular from the center of the axle, then the abrasion increases with the degree of inclination. (See Figs. 8 and 10.) Increasing the bearing-surface of the rails on curves makes the worn wheels especially run more nearly radial to the curve, lessening the

abrasion.

PROPOSED SECTIONS.

In designing the sections of rails, I have made five series, giving fifteen sections of twelve different weights, ranging from 50 to 105 pounds, for ordinary steam railroads, and four series of light rails for mining, agricultural, manufacturing and construction purposes. The latter are not included in this paper.

By looking at the drawings of the sections, it will be noticed that the inclined surfaces of the section are given by ratio of length of base to the height of the perpendicular, instead of in degrees. The line of the radii for the sides of the webs is above the center of the web, so as to make the lower portion of the web thicker for four important reasons and purposes, viz., 1st, to more nearly equalize the heat of the section between the base and the head, permitting colder rolling and lessening the amount of cold straightening required; 2d, to lower the neutral axis, better equalizing the strain of the metal between the base and head, and checking the tendency to permanent set; 3d, to increase the moment of inertia of the section; and 4th, to check the tendency of the web to bend near the base of the rail under heavy traffic.

The bases of the rails are all thick and of less width than the height of the section, designed so largely for the purpose of permitting the sections to be made as physically hard and tough as the first rails used. Rails made for a long service of years must have a heavy base to provide for wear and oxidation.

Series C, D and E will be used largely upon metallic ties or upon tie plates, where they will be held firmly upon the bearings.

Observations on the broad-headed 80-pound rails of the N. Y. C. & H. R. R. R. show that they have far less tendency to roll in the