Jackhammer, Pin-Tumbler Lock, Safety Pin, Gyroscopes

Johnathan Coach invented the modern Jackhammer in 1848. Coach was from Philadelphia. Jackhammers are hammer drills. Coach's assistant, Fowle, innovated the jackhammer to use compressed air. Buildings and even skyscrapers can be demolished using high-powered jackhammers. The jackhammer reduces the need for importation. The jackhammer also reduces delays during road construction.

Linas Yale Sr. was born in Connecticut in 1791. He opened a lock shop when he was in his forties. He invented the pin tumbler lock in 1843 to protect valuable stuff. The pin tumbler lock contains pins in a cylindrical drum. Key lines up pins to rotate the cylinder.  It was harder to pick than older locks. Linas Yale Jr, his son, continued his father's work. It is used in the common door lock.

Walter Hunt was born in New York in 1796. Hunt invented a version of the sewing machine in 1832. He had experience with needles and the sewing industry. He invented the safety pin in 1849. Safety pins are simple folding needles. Pins have sharp heads that can hurt if they stick you. Advertised to nurses and to wives for diapers and clothes. Safety pins are still used in the cloth industry today.

Leon Foucault was born in Paris in 1819. Foucault became interested in physics. He helped discover the speed of light. He experimented to prove the rotation of the earth in 1851. He invented the Gyroscope in 1852. Foucault proved the earth's rotation by using a gyroscope. He also helped put man on the moon. It made GPS possible.