The efficiency of this combined air service is credited with having contributed in an important degree, first to retarding the movement of supplies from the enemy rear to the enemy fighting line, and next to disturbance of the enemy in retreat. The Americans especially distinguished themselves by flying at high speed along the last of the enemy trenches and clearing up the German troops therein by continuous streams of machine gun fire. American flyers also made successful raids across the German border, blowing up munitions works, railway centers, and German troops at concentration points. Between early September and late October, 1918, they dropped thousands of tons of high explosives inside of Germany. At the same time, in association with British and Canadian aviators, they put a definite end to German air raids upon the British Isles and interior France. The Canadian air service during the summer and early autumn of 1918 increased at the rate of 300 planes per month, all manufactured in Canada. LIBERTY MOTORS AND AIR SERVICE After July, 1918, the output of Liberty motors for the Government caught up with the immediate demand. It increased until in October it reached a rate of about 5,000 a month. The Ford factory at Detroit alone reported at the end of October an established monthly rate of increase of over 1,500. AMERICAN FLYERS DOWN 473 PLANES IN TWO MONTHS American flyers made a great record in the closing days of war. In the period from September 12 to 11:00 o'clock on the morning of November 11, American aviators claim they brought down 473 German machines. Of this number, 353 have been confirmed officially. Day bombing groups from the time they began operations dropped a total of 116,818 kilograms of bombs within the German lines. THE WAR IN THE AIR Aviation is the most perilous of all services, calling for young bodies, high spirit, quick wit, personal initiative, and unshakable nerve. Thus it has drawn in the best and brightest of America's sons--brilliant, clear-eyed, steady youths, who take the air and its perils with joyous ardor. The danger, the romance, the thrill of air fighting, are things that never were known in war until this one called into being vast aerial navies that grappled in the sky and rained upon the earth below "a ghastly dew" of blood. There are no tales of this war more fascinating than those that have been told by these men. Courage and modesty being inseparable, our aviators avoid print and cannot be interviewed with any satisfaction. But sometimes they write home to a mother, a sweetheart or a pal, and these letters now and then come to light. CHANCE OF LIVING NOW