Boeing constructed a supersonic twin sphere wind tunnel in the mid-1950s for the Dyna-Soar X-20, the SST (Supersonic Transport), and other projects. When the spheres were being demolished, they discovered over 3 million of these tin cans. They were used to help with temperature control in the giant spheres as air was pumped in and rushed out. This process was similar to using those high pressure pump air cans to clean your keyboard. When the air rushes out too fast for a long time, the can gets very cold. These millions of tin cans helped to keep ice from developing on the machinery in the wind tunnel. Bardahl Manufacturing Company was started by Ole Bardahl, a Norwegian immigrant whocame to the United States in 1922 and settled in the Ballard neighborhood of Seattle. He developed a unique formula for oil additives that was praised for its high quality and which ultimately became the leading oil additive used in engines in the US.