Pound (mass) No standards of the Tower pound are known to have survived. The Tower pound was equivalent to about 350 grams. The merchants' pound ("mercantile pound", "libra mercantoria", or "commercial pound") was considered to be composed of 25 rather than 20 Tower shillings of 12 pence. It was equal to 9,600 wheat grains (15 tower ounces or 6,750 grains) and was used in England until the 14th century for goods other than money and medicine ("electuaries"). The London pound is that of the Hansa, as used in their various trading places. The London pound is based on 16 ounces, each ounce
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: