The British established a petroleum depot at Calais of an immensity previously unprecedented, where all products required for the organization of transport were stored; and it must be noted that lubricants of all kinds were as essential as gasoline itself, to keep moving the wheels of the innumerable motors that were employed by the various arms of the service. If petroleum was the life blood of activity in the battle areas, it was not less so of the munition factories where the means of offense were fabricated. Had a real petroleum famine arisen during the days when factories in Britain and France were straining every effort to keep their armies supplied with the means of combat it would have been an incalculable catastrophe. Though the Allies, once they really awakened to the dangers of the situation, had pursued the policy of piling up reserves of petroleum products there were times when the failure of a single tanker to arrive on schedule time from this side of the Atlantic caused grave apprehension; and when in April, 1917, the United States entered the war, reserve supplies had fallen dangerously low. If only because it placed the entire oil resources of America at the disposal of the Allies, the entry of the United States into the conflict proved the salvation of their cause; and the story of what the oil interests of this country did to strengthen the hands of the fighting men is one of the brightest chapters in the history of the war. After the armistice, Marshal Foch summarized that achievement in these words: “No military operation of the Allies on sea, on land, under sea or in the air was ever interrupted by the lack of petroleum supplies.” Unquestionably one of the motives which actuated Germany when, in February 1917, she decreed unrestricted submarine warfare and ordered the Stars and Stripes off the seas, was the hope of cutting off the petroleum supplies of her foes. Even before President Wilson declared war, several American tankers had been sunk by German U-boats. The German Government fully understood that a cessation of oil shipments from American ports would mean an almost immediate paralysis of belligerent effectiveness in her foes and the “German Peace,” for which they had long been manoeuvring, would have been accomplished. When activity was keenest on the Western front eighty per cent. of the oil and oil fuel used by the Allies came from the United States. After the war was over it was revealed that forty-eight per cent. of the fighting force of the British navy was dependent on oil for fuel and any delay in the supply would have brought the Allies down with a crash.