Cash register
The person who invented the cash register was James Ritty, who came from Ohio and owned a bar in Dayton. In 1878, he found out that the people who worked in the bar kept on stealing money. When he noticed a part of a ship which counted how many times the propeller turned, he used the same idea to build a machine that could count different amount of sales. He got a patent on his machine and started a company the next year to make them, but it was not popular and the company, which became the National Cash Register Company in 1884, was sold to John H. Patterson.