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 .
fter a failed attempt on 14 Dec 1903 by Wilbur, the Wrights flew the world's first powered airplane at Kitty Hawk on 17 Dec 1903. Beginning at 10:35 AM, Orville flew it about 120-feet or 36.5 meters (in about 12 seconds.