It is quite true that the various branches of knowledge are interrelated very intimately, and that an advance in one will often suggest a development in another.

Both the prices of all the particular objects of international trade and the general levels of prices in any two trading countries come to be pretty definitely interrelated.

The chapters are interrelated insofar as they purport to be a sequence of pictures describing some of my experiences and setting forth a few of my observations in Belgium, in Germany, in France and in England during the first three months of hostilities.