Pound (mass) divided as the tower ounce. It never became a legal standard in England; the use of this pound waxed and waned with the influence of the Hansa itself. A London pound was equal to 7,200 troy grains (16 troy ounces) or, equivalently, 10,240 tower grains (16 tower ounces). In the United States, the avoirdupois pound as a unit of mass has been officially defined in terms of the kilogram since the Mendenhall Order of 1893. That Order defined the pound to be pounds to a kilogram. The following year, this relationship was refined as pounds to a kilogram, following a
How many angels can dance on the head of a pin? about how many could perch at the same time on the head of a pin"". Dorothy L. Sayers argued that the question was "simply a debating exercise" and that the answer "usually adjudged correct" was stated as, "Angels are pure intelligences, not material, but limited, so that they have location in space, but not extension." Sayers compares the question to that of how many people's thoughts can be concentrated upon a particular pin at the same time. She concludes that infinitely many angels can be located on the head of a pin, since they do not occupy any space there: