Sieve together the flour, bicarbonate of soda and cream of tartar. Stir in the sugar, and rub in the butter. Make a well in the centre and stir in the beaten egg and enough milk to make a thin batter. Add the vinegar last. Heat a griddle, hotplate or heavy frying pan, and grease it well. Put two tablespoons of the batter on to the hot surface and cook until brown on the underside. Turn and finish cooking the other side. Butter well and eat hot. These were traditionally made as large pancakes and spread with butter, then piled on a plate and cut into quarters.