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 first jet plane that was ever made dates to pre-World War II Germany. This was the Heinkel He 178. The Heinkel He 178 proved to be beneficial to Germany's later war ef â¦ forts after initial bugs were worked out of the original design.