The eminent author of this book has made a profound study of the economics that apply to many of the problems which the Civil Engineer is called upon to solve, and it will be widely read by all engineers who are determined to be in the forefront of their profession. It, therefore, seems most fitting that in this book there should appear a chapter dealing with the principles which must apply to a phase of the work of the Military Engineer, work which any one of the many readers may be called upon at some time to carry on.

Colonel P. S. Bond, Corps of Engineers, U. S. Army, was selected to prepare this chapter because of his intimate knowledge of the subject, acquired by study and by practice. He has presented it clearly and logically, pointing out the essential differences which must prevail between the principles that govern the building of bridges, according as they are intended for military use or to serve peaceful purposes.

He has stressed particularly the all important time element in war enterprises, and has shown that what in civil practice might be wilful waste, in war may be the greatest of all economic measures. In fact, so tremendous is the cost of conducting a modern war, it is hardly too much to say that any expenditure of money or of material which will shorten its duration is easily justified. A careful reading of this chapter is, therefore, earnestly recommended to all of those to whom the Army must look for help when next we are called upon to take up arms in the defense of our rights and the rights of humanity.

ECONOMICS OF MILITARY BRIDGING

Streams constitute one of the greatest obstacles to military operations, and bridge building is, accordingly, one of the chief duties of the military engineer.

Fundamental Economics of Military Engineering

Military bridge engineering is an adaptation, in a simple and frequently crude and makeshift form, of civil practice to military needs. The fundamental difference between civil and military practice is in their economic aspects. The technical details of military bridges are characterized by extreme simplicity, which is demanded by the conditions under which they must be built. They will present little difficulty to the engineer having a good general knowledge of civil practice.

But the successful practice of military engineering, including bridging, demands a knowledge of the economic principles which are specially applicable to warfare. Mistakes in economic judgment will have more far-reaching and disastrous consequences in war than in peace—there will be greater opportunities for tremendous profits or ruinous losses. A practical