Discussion on “graphic method for speed-time and distance-time curves” (Woodruff), New York, November 13, 1914. (see proceedings for November, 1914)

Selby Haar: In looking over this paper the thought occurred to me that since it is a graphical method it is open to the objection to most graphical methods, namely, one must be very careful in the construction if the results are to be used for anything more than demonstration purposes. These methods are quite frequently used, not so much in railway work as in some other branches of the electrical industry, for obtaining guarantees to be used in contracts, and I have found that they cannot be relied upon closely enough for such purposes.