1 Discard any hammer with mushroomed or chipped face or with cracks in the claw or eye sections. 2  Wear safety glasses or goggles, or a face shield (with safety glasses or goggles).  Strike a hammer blow squarely with the striking face parallel to the surface being struck.
The first jet airplane was the Heinkel He 178 made in Germany in 1939, right before the outbreak of World War II .
The development of the world's first practical design for an ICBM, A9/10, intended for use in bombing New York and other American cities, was undertaken in Nazi Germany by the team of Wernher von Braun under Projekt Amerika.he first launch took place on 15 May 1957 and led to an unintended crash 400 km (250 mi) from the site. The first successful test followed on 21 August 1957; the R-7 flew over 6,000 km (3,700 mi) and became the world's first ICBM.