The Wealth of Nations by Part 1 Chapter 11 Page 116

Thus in the Assize of Bread and Ale, of the 51st of Henry III, the price of bread was regulated according to the different prices of wheat, from one shilling to twenty shillings the quarter, of the money of those times. But in the manuscripts from which all the different editions of the statutes, preceding that of Mr. Ruffhead, were printed, the copiers had never transcribed this regulation beyond the price of twelve shillings. Several writers, therefore, being misled by this faulty transcription, very naturally concluded that the middle price, or six shillings the quarter, equal to about eighteen shillings of our present money, was the ordinary or average price of wheat at that time.

In the Statute of Tumbrel and Pillory, enacted nearly about the same time, the price of ale is regulated according to every sixpence rise in