Barcol hardness test the Barcol impressor was developed by Walter Colman as a hand-held, portable means of assessing the hardness of a material during World War II. The United States Army Air Corps required a hand-held method of checking the hardness of rivets due to concerns that aircraft could be sabotaged by replacing normal rivets with soft lead or wooden ones which would fail during flight. The impressor operates when the tip is pressed against the material in question. The hardness of the material determines how far the tip indents and this is transferred by a tension spring and lever to be read
Carlo Janka of the classic Lauberhorn slope, on 18 January. Janka competed in his first international FIS race in December 2001 at age 15. Not until four years later did he reach the podium, but success came in all four disciplines. Janka began racing on the FIS European Cup circuit in January 2004. He earned his first two World Cup starts in December 2005, but did not finish either race. At the 2006 Junior World Championships in Mt. Ste. Anne, Quebec, Canada, he won the bronze medal in giant slalom, and he finished the 2007 season in fourth place in the overall