Poached Eggs

There is a puzzling cluster of rules surrounding the poaching of an egg: The water should be kept simmering; vinegar should be added to the water to hasten the coagulation of the white; salt should be added to reinforce the vinegar’s work; salt should not be added because it toughens the whites or because it counteracts the vinegar’s firming action; the eggs should always be broken first into a cup or saucer to ascertain their freshness; they should be poached one at a time in a simulated whirlpool to prevent the white from spreading all over the place and one should deftly snatch the escaping edges of white from the far reaches of the whirlpool, folding them back over the yolk with a spoon; the eggs should be fresh . . .