One of the author's fundamental motives in writing "Bridge Engineering" was to provide bridge specialists with a means of estimating quite accurately, and at the same time very quickly, the costs of substructure, superstructure, and approaches for any kind of bridge upon which they are ever likely to have to figure. Rather to his surprise, the numerous reviewers of the work almost entirely overlooked this important characteristic of the treatise. As it is one of the most valuable features thereof, the author, in order to make known this special usefulness, drafted a set of four problems for solution, solely by means of the curves of quantities, tables, formulae, and other information scattered throughout the book; and arranged for a series of competitions among the senior students in a number of technical schools, and afterwards, by a comparison of the marks resulting from a pre-arranged system of grading, effecting a competition among the said schools themselves by comparing in the columns of the technical press the sums of the marks of the three prize winners in each school. The judges were appointed, and the system of marking was fixed, all ready for the comparison of the unsigned competitive papers; but the entering of America into the Great War so upset the technical students all over the country that the competition had to be abandoned. The author is ready to provide the promised prizes (books of no great financial worth, but valuable as souvenirs of success in competition), in case that any of the teachers of engineering show a desire to have the offer renewed for a new set of problems. As a matter of possible interest, the original list of questions is reproduced at the end of this chapter; and the author suggests that, for the sake of practice in quick computation, engineering students try their wits on the solution of them.

In the author's practice during the last three or four years he has made very quickly many cost estimates on steam-railway, electric-railway, highway, and combined bridges by means of the diagrams, tables, and formulae of "Bridge Engineering" for rolled I-beam spans, plate-girder spans (both deck and half-through), riveted-truss simple-spans, pin-connected simple-spans, swing spans, cantilevers, suspension bridges, and reinforced-concrete structures; and the results when tested have been found to be exceedingly accurate.  The  estimating  of  costs  of  structures in this manner is a very easy task  compared  with  the  job  of  making  similar  computations

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