With air transport five years old, by 1930 the speed of planes was only about 100 miles per hour. Engineers and transport men agreed that the air transport plane must be faster. The planes of that day still had a considerable amount of external bracing and many of them were biplanes with strut and wire wing bracings. This caused the drag that was holding down the speed of the transport. Many of these planes had so many bracings that they whistled as they flew. To make a profit, the air transport operators had to have faster, quieter, and yet more comfortable airplanes. They must also be more easily maintained. In 1921, Boeing came up with a plane that, while not the final answer to the air transport problem, was to point the way to the modern all-metal, monoplane type of air transports. This plane was the Boeing _Monomail_. The _Monomail_ was big, fast, and comfortable, and it carried a big pay load. It was the first practical low-wing, all-metal transport to be put into service in this country. It carried five passengers, their baggage, and 1,750 pounds of mail or cargo, at a cruising speed of 140 miles per hour. The _Monomail_ was the sensation of air transport in 1931, and set the pace for future transport planes. [Illustration: THE BOEING _MONOMAIL_ WEIGHED 4 TONS EMPTY AND CARRIED A 1,750-POUND PAYLOAD. IT HAD A SMOOTH ALUMINIUM COVERING AND THE LANDING GEAR RETRACTED INTO THE WINGS.] DONALD DOUGLAS’ DREAM COMES TRUE The Boeing people, though pleased with the reception and performance of the _Monomail_, knew that the single-engine plane was not the final answer. If the engine failed, the plane must land. If the plane was over rough or mountainous country, forced landings meant danger. A big plane must have two engines, one of which could keep the plane flying if the other failed. Boeing went to work with this in mind. Near Los Angeles, the young man who had been dreaming of big commercial transport planes since the Wright Brothers’ trials at Fort Meyer, also was thinking of two-engined transports that could fly on one engine. From the time Donald Douglas’ _World Cruisers_ had circled the globe, his aircraft had grown larger and larger. His orders, however, were for Army, Navy, and Coast Guard planes; not for great commercial airliners. Although Donald Douglas had achieved a great deal of international fame as the result of the round-the-world flight and was highly respected in military circles, few other people knew him. A quiet, industrious young man, he had put all his earnings back into his business and had continued to work on his dream of big, roomy, smooth-flying airliners. He visualized air transport flying from coast to coast and from country to country in a great network of airlines that would link the whole world.