When the Arab Caliphs conquered the southern and eastern Mediterranean countries, they found in Egypt the Egypto-Roman pound, 1/125 of the Alexandrian talent; they adopted it, and divided it for coin-weight purposes into 72 mithkals, just as the Roman Emperors had divided the old As pound into 72 aurei; so 6 mithkals = the libra-ounce of 437 grains, just as 6 aurei = the As-ounce of 420-2/3 grains. It is not improbable that the survival of the Roman commercial pound in Saxon England was strengthened by commercial and scientific relations with the Moors of Spain. King Offa of Mercia struck a gold coin with an Arabic inscription, dated 157 of the Hejira = A.D. 774. However this may have been, there seems no doubt that the Roman pound, raised to 16 ounces, was the standard of England before as after the Norman conquest, and there is no evidence of it having ever been in abeyance. In early Plantagenet times there was a sexdecimal series of weights: The Stone of 16 lb. The Wey of 16 stone = 256 lb. There was also the Hundredweight, of which 20 made a ton of 2000 lb.; and 20 weys made a Last of approximately 5120 lb. or 2-1/2 tons. The pound was divided into 16 ounces, each = 437 grains, and the ounce into 16 drams or drops = 27·3 grains. Both before and after the Conquest there was another pound used in the mints, like the As in Rome. It was of Tower, or Cologne-marc, standard. There were doubtless many local variations of commercial standard, especially in measures of capacity, and it was the necessity of checking these which made King John and his successors declare that ‘there should be one standard throughout our kingdom, whether in weights or in measures.’ But the king had a mint-pound of his own, and he had to reconcile the existence of the coinage-pound and of the commercial pound with the customary declaration of unity of weight made in each reign. The king’s councillors evaded the difficulty by pretending that the measures of capacity were based on the mint-pound and, in statutes where a commercial pound had to be mentioned, by pretending that this was equal to 25 shillings weight or 15 ounces of the mint-pound. This deception led to others, so that, to make out the meaning of a statute of weights and measures, one must be able to read between the lines, and to be prepared for misleading and contradictory statements. I will take as an instance, Act 51 Henry III (1267): An English peny called a Sterling, round and without clipping, shall weigh 32 wheat corns in the midst of the ear; and 20 d. do make an Ounce, and 12 Ounces one Pound, and 8 Pounds do make a gallon of wine and 8 gallons of wine do make a London Bushel which is the eighth part of a Quarter. This declaration may be thus interpreted: