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 .
During the spring and summer of 1903, they were consumed with leaping that final hurdle into history. On December 17, 1903, Wilbur and Orville Wright made four brief flights at Kitty Hawk with their first powered aircraft. The Wright brothers had invented the first successful airplane. Go to Designing the Flyer >>