a series of letters by the author and others, that were printed at first in the Railroad Gazette, and later also in the Engineering Record, in which letters the subject of equivalents was thoroughly and exhaustively treated. These proved that the "Equivalent Uniform-Load Method" gives results which are accurate enough for all practical purposes, and that neither the "Single Concentrated-Load Method" nor the "Double Concentrated-Load Method" gives results coinciding at all closely with those found by the theoretically exact method of "Wheel Concentrations."

In November 1892 the author sent a circular letter to all the chief engineers of railroads in the United States and Canada who were members (in any grade) of the American Society of Civil Engineers, and to every other member of that society connected with or specially interested in the designing, building, or operating of railroad bridges. This letter solicited a ballot on certain "Disputed Points in Railway Bridge Designing," foremost among which were those of standard live loads and a simple equivalent method for computation. The number of responses received was as great as could have been expected; and the result was that about eighty-two per cent of those who voted favored and eighteen per cent opposed the adoption of "a Standard System of Live Loads for Railway Bridges" similar to that proposed by the author. Eighty-two per cent also of those who voted were in favor of abandoning the "Concentrated Wheel-Load Method," and eighteen per cent were in favor of retaining it. Of the former, seventy-eight per cent favored the "Equivalent Uniform-Load Method," and twenty-two per cent were in favor of either the "Single" or the "Double Concentration Method." A number of gentlemen who responded made valuable suggestions in respect to the standard system of live loads propounded, and by the aid of these the author prepared a proposed "Compromise Standard System of Live Loads for Railway Bridges," and submitted the same, as before, for final ballot in May 1893.

The number of replies received showed that great interest was taken in the question; and the result of the ballot was