Put into a pan a pound of crushed loaf sugar and half a pint of cold water.
Stir gently over the fire until the sugar is dissolved. When nearly boiling, add a good pinch of cream of tartar and boil without stirring until it reaches 258 F. in cold weather or 260 F. in hotthat is, until it forms a hard lump in cold water. Remove from the fire, add colouring and flavouring, and pour on a buttered marble slab, preferably through buttered candy bars. As it begins to cool, turn the ends and edges inwards with a buttered knife. When cool enough to handle, dust it with powdered sugar, take it up and pull gently (being careful not to twist it) until it is dull. Cut in pieces
Confectionery is an important industry in the capital, and the world-famous rock is one of the triumphs of the Scottish confectioner's art.