> a gritty gruel of salty flakes coated with the oleic pall of margarine.

Yuck; you're supposed to use milk, and butter.

> Hannah Glasse’s procedure published in 1747 in The Art of Cookery Made Plain and Easy is, minus the long s’s, still just about how I make them today:[with real potatoes, milk and butter]:

Exactly.

Did you read the whole article? You might like it.