A silver dollar is an inch in diameter. Is this the size you mean for Nigella's American Breakfast Pancakes?
Nigella's American Breakfast Pancakes (from HOW TO BE A DOMESTIC GODDESS) are thick, fluffy American-style pancakes. Nigella mentions in the recipe that she makes these pancakes "silver dollar" sized.
Silver dollar pancakes are the name given to small pancakes in the US, larger pancakes are sometimes known as flapjacks. They are usually approximately 5cm (2 inches) in diameter and each is made with about one (15ml) tablespoonful of batter. The name originates from the idea that the pancakes were slightly larger than the old US silver dollar (coins produced before 1979, after this date the size changed). However the term really just refers to smaller bite-sized pancakes, rather than being an exact measurement.