THE first three years of Canada's participation in the Great World War were Days of Preparation. In no way, save in the readiness of the people to make every sacrifice, was Canada prepared for war. To give the story of the Dominion's contribution to theworld-struggle, it has been thought wise, before taking up the work of the army on the battlefields of Europe, to give a detailed account of the home activities—the turning of the industries of the country to war needs, the voluntary contributions for war purposes, and the surrender of the man-power of the nation for the field of battle. As this volume goes to press (September, 1918) while the war is still in progress, it is naturally impossible to give, in any department of war-work, the complete story of Canada's part in the struggle. But this volume will be found to contain all that is necessary for under-standing why Canada has played such an important part in aiding the Allies to thwart the mad schemes of the Central Powers for world-domination. In the final volume of this series carefully prepared statistics will complete the tale of Canada's war effort. The volumes which follow the present one will give a connected story of the work of the Canadian divisions in the various fields of military operations. Matter which would break the flow of the narrative, such as the treatment of Canadian prisoners in Germany, Canada's contribution to Britain's sea-power and to the control of the air, the work of the Army Medical Corps, etc., will be given in appendices to the various volumes.