Carat (mass) quarters" of 15 grains troy each. Likewise, the ounce troy was divisible into 24 "ounce carats" of 20 grains troy each; the ounce carat was divisible into four "ounce grains" of 5 grains troy each; and the ounce grain was divisible into four "ounce quarters" of grains troy each. The "solidus" was also a Roman weight unit. There is literary evidence that the weight of 72 coins of the type called "solidus" was exactly 1 Roman pound, and that the weight of 1 "solidus" was 24 "siliquae". The weight of a Roman pound is generally believed to have been 327.45
Post-harvest losses (grains) of edible from less-desired products is always difficult to achieve but, even so, there are significant differences in milling efficiency. In the case of rice, milling outturns can vary from 60% or less to around 67%, depending on the efficiency of the mill. Even a 1% increase in yield of whole grain rice can thus result in huge increases in national food resources. Grains are produced on a seasonal basis. In many places there is only one harvest a year. Thus most production of maize, wheat, rice, sorghum, millet, etc. must be held in storage for periods varying from a