In the spring of 1895, Wilbur and Orville Wright moved their printing and bicycle shops under one roof in The Wright Cycle Company building. There the brothers concentrated on designing and building their own custom make of bicycles. They devised a gas engine to power their tools, mastered welding, and built chain drives, brakes, and hubs, all crucial skills later used to build the world's first airplanes. The business proved profitable, enabling the brothers during the quiet winter months to spend more time inventing. By the time they moved to a larger shop in 1897, they already had an awakening interest in human flight.