A draft is (1) a drawing, sketch, or design; (2) a current of air; (3) the act of drawing or pulling loads; (4) the taking of money or other supplies from a source; (5) selection by lot. A draught refers to (1) drawing liquid from a container; (2) the act of drinking; (3) a drink. Both terms refer to air currents but otherwise have distinct meanings, although in Great Britain draught is the preferred spelling for several of the meanings listed under draft. Examples: "Suddenly she felt a cold draft (or draught) of fresh air." "Jim took a long draught of cold beer." (In recent years, draft has been more frequently used in this sense.) "I shall issue à draft against your account at the bank." "He owns two heavy draft horses." "When a draft of fresh air entered the room, he took a draught of it into his lungs."
Dictionary of problem words and expressions. Harry Shaw. 1975.