Metal Detector: (3. 1) Life: Before World War II, Kosacki was a technician in the Artillery Department of the Polish Ministry of National Defense. Shortly before the war, he joined the clandestine Special Signals Unit, a secret institute that worked on electronic appliances for the army. Following the 1939 invasion of Poland, he managed to get to the United Kingdom, where he continued his service in the Polish Army as a signals officer. In 1941 he devised his Polish Mine Detector. It was to be used for the first time in action on Second Battle of El Alamein. Five hundred of these detectors were issued to Eighth Army. They doubled the speed at which heavily mined sands could be cleared, from 100 to 200 meters an hour. The device was used until the 1991 Gulf War. After the war he returned to Poland, where he became a pioneer of electronics and nuclear machinery. For many years he held the chair in electronics at the Institute for Nuclear Research at Otwock - šwierk. He was also a professor at the Military Technical Academy in Warsaw. He died in 1990 and was buried with military honors