History 5 Lesson 130

Light Switch 

John Henry Holmes was born in England in 1857. Joseph swan developed an early light bulbs company.  Holmes attended Swan’s demonstration. Holmes invented the light switch in 1884. Light switches make it easy to conroe circuits. Instantly turned it on or off. Safe prevents arcing and fire hazard. Switch cna control larger relays or switches for more high-powered circuits. William J. Newton extended Holmes’ invention to toggle switch. He was installed by builders. It was required by building and electric codes. 

Skyscraper

William Jenney was born in 1832 in Massachusetts. Learned engineering in France. Fought in the Civil War (North). He married in 1867. Invented a skyscraper in 1884 after discussion with his wife. Skyscraper: 328 feet tall or more. Replaces load-bearing wall with load bearing steel frame. Elvatos is crucial to skyscraper design. Strong foundation keeps it safe during earthquakes. Increase population density in popular areas. The Home Insurance Building was the first skyscraper. Others quickly followed. Chicago and New York were the focus of skyscrapers. Moderate success in Europe initially. 

Dishwasher 

Josephine Chochrane was born in Ohio in 1839. Got married in the 1850s to a business owner. They hosted large partes on fine china. Josephine wanted an easier way to clean dirty dishes. She invented dishwashers in 1886. It automatically cleans dirty dishes. The operation is more complex. Racks hold dirty dishes. Jets spray them with hot water. This sterilizes the dishes. Josephine sold them to her friends first. She then showed it off at the 1893 world’s hair in Chicago. Commercial and dining industries were interested. began making their way into homes in the 1950s.   

Electromagnetic Waves

Heinrich Hertz was born in 1857 in Germany. Studied engineering with Jelmhotter in Berlin. Hertz thought it was too difficult at first to prove Maxwell’s waves. But he noticed something by accident. Proved the existence of electromagnetic waves in 1887. Electromagnetic radiation that propagates through space. Traveling at the speed of light. Electric and Magnetic fields. They can carry information. Useful in the medical field. Hertz didn’t think they would be useful. Died at 36 years old. Others picked up his work. Wireless telegraphy invented by 1894.      

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