Ice Cream Maker, Computer Scanner, Keyed LockMaking ice cream as we know and love it started in 1846 with a woman from New Jersey named Nancy Johnson. She built a handcranked machine that mixed a creamy concoction in a bowl surrounded by ice. Once the tricky process of making ice cream was licked, it quickly became a cool dessert of choice for a hot day. By 1920 over 150 million gallons were made every year, and ice cream's popularity has only grown since then. Next, in 1975 a team of engineers at Kurzweil computer products took the heart of a satellite's camera, something called a charged coupling device or c.c.d., and used it to make electronic copies of documents. This first scanner's c.c.d. was an electronic eye made up of a line of 500 light-sensitive sensors. These sensors took the light that reflected off a document and turned it into electrical impulses. Finally, the Romans were the first to make locks out of metal, but instead of lifting pins, their keys had to move through a small maze called a ward. Metal ward locks remained popular for centuries, but in order to stay ahead of burglars, their designs had become extremely complicated. Around 1500 the pin and tumbler design was reintroduced, now with metal. This simpler system proved a more formidable deterrent to intruders and was easier for locksmiths to manufacture.
