the author has given up the attempt to induce his brother specialists to collaborate with him in the production of the proposed treatise on "The Economics of Engineering." Instead he presents to the profession as a possible starter for such a joint work this treatise on bridge economics, in the hope that some day American engineers will awaken to the importance of having available either a number of small books on the economics of the various specialties or else a joint work similar to the one which he has advocated. and which appears at present to be too much in advance of the times.