Loading The Dishwasher

Little Johnny loads the last of the dirty dishes into the dishwasher. His little hands shaking and mouth agape in awe of the magical mechanical man living in the kitchen, hidden from view in the box beneath the countertop. He is handed the dishes and soon after sends back sparkling clean china for the happy family to make foul once again. It's a job that little Johnny would love to do. Perhaps one day when he is tall enough to reach the sink. A dishwasher is a mechanical device for cleaning dishes and eating utensils. Dishwashers can be found in restaurants and private homes. Unlike manual dishwashing, which relies largely on physical scrubbing to remove soiling, the mechanical dishwasher cleans by spraying hot water, typically between 55 to 75 °C (130 to 170 °F) at the dishes, with lower temperatures used for delicate items. A mix of water and detergent is used for cleaning purposes, followed by clean water to remove the detergent residue. Some dishwashers have multiple wash and rinse periods within the complete cycle. In some dishwashers, a rinsing aid can be added to the rinse cycle to improve drying and avoid water spots remaining on dry items. The first reports of a mechanical dishwashing device are of an 1850 patent by Joel Houghton of a hand-powered device. This device was made of wood and was cranked by hand while water sprayed onto the dishes. This device was both slow and unreliable. Another patent was granted to L.A. Alexander in 1865 that was similar to the first but featured a hand-cranked rack system. Neither device was practical or widely accepted.