The Book of Marvels: A Compendium of Everyday Things

Unlike the mousetrap, perfect from the outset in form and function, the toaster has changed. There used to be two small doors hinged at the bottom. You swung them down, laid the bread upon them, then clicked them shut. Halfway through, you opened them again and flipped the slices to brown the other sides. This took skill. Many breakfast makers burned their fingers. Early doorless models simplified the task, though they sometimes popped the toast a foot about the grills. You had to remain at your toasting station, alert and quick, to snatch the finished product from the air. It took years of observation in toaster labs for someone to tweak the math and double the slices. The other change is more significant. The slots have widened. This redesign takes in the bagel, the scone, the croissant, the English muffin, the kaiser bun. What's missing? A slot thin enough to toast pitas, thinner still for tortillas. Blessed is the country that would fund the creation of such an amenable machine and then deliver it to every household in the land. 
- from Lorna Crozier's The Book of Marvels