From the technology-is-where-you-can-find-it department: Until the 17th Century, the kitchen had no single-purpose appliances. The first? The coffee grinder, and, later, the coffee brewer.
Kitchen historians say the fascination with kitchen machinery (some might say gadgets) spawned by the grinder led to other breakthroughs at the hearth, including a wind-up spit that rotated meat over the fire without the aid of a servant or caged dog. (Really. The dog was housed in a circular contraption, like a hamster's wheel, that was attached to the spit. As the dog ran, the spit turned.)
The biggest advances in the kitchen came with the Industrial Revolution, when every appliance we know today, except the microwave oven, garbage disposal and trash compactor, was invented. But while the dishwasher, washing machine and dryer were first marketed in the late 19th Century, it took until World War I, when the ranks of servants were thinned by military service, for the appliances to catch on.