Pennyweight Troy weights were defined in such a way that the old Tower pound came out to exactly 5400 Troy grains (also known as barleycorns), the Tower pennyweight Troy grains (and thus approximately 1.46 grams). After 1527, the English pennyweight was the Troy pennyweight. of 24 Troy grains. Thus the Troy pound, ounce, and pennyweight, with their definitions given in terms of the Troy grain instead of in terms of the Tower grain, were 1/15 or 6.667% more than the Tower equivalents. The Troy pound and the pennyweight lost their official status in the United Kingdom in the Weights and Measures
Troy weight the sceat with the silver penny. This coin was derived from half of a silver dirhem. The weights were then derived by a count of coins, by a mix of Charlemagne and Roman systems. A shilling was set to twelve pence, an ounce to twenty pence, and a pound to twelve ounces or twenty shillings. The penny was quite a lot of money, so weight by coins was not a general practice. Later kings debased the coin, both in weight and fineness. The original pound divided was the tower pound of 5400 grains, but a later pound of 5760 grains