The first public stamps of this kind that were affixed to the current metals, seem in many cases to have been intended to ascertain, what it was both most difficult and most important to ascertain, the goodness or fineness of the metal, and to have resembled the sterling mark which is at present affixed to plate and bars of silver, or the Spanish mark which is sometimes affixed to ingots of gold, and which, being struck only upon one side of the piece, and not covering the whole surface, ascertains the fineness, but not the weight of the metal. Abraham weighs to Ephron the four hundred shekels of silver which he had agreed to pay for the field of Machpelah. They are said, however, to be the current money of the merchant, and yet are received by weight, and not by tale, in the same manner as ingots of gold and bars of silver are at present. The revenues of the ancient Saxon kings of England are said to have been paid, not in money, but in kind, that is, in victuals and provisions of all sorts. William the Conqueror introduced the custom of paying them in money. This money, however, was for a long time, received at the exchequer, by weight, and not by tale. The inconveniency and difficulty of weighing those metals with exactness, gave occasion to the institution of coins, of which the stamp, covering entirely both sides of the piece, and sometimes the edges too, was supposed to ascertain not only the fineness, but the weight of the metal. Such coins, therefore, were received by tale, as at present, without the trouble of weighing.