Imperial and US customary measurement systems different concepts – the imperial gallon is defined in terms of the volume occupied by a specified mass of water, while the US gallon is specified in terms of cubic linear measure. Notes Notes Units of weight in both the imperial and US customary system always used the same standard, though differences in multiples of the avoirdupois pound developed in the nineteenth century. Both systems used the three different scales – the avoirdupois system for general use, the troy system for precious metals and the apothecaries system in the pharmacy industry. The term "weight" and "mass" are used interchangeably in
Cross of Gold speech proposed a monetary system based on bimetallism, in which the new currency would be equal to a given amount of gold, or a larger amount of silver; at the time a given weight of gold was worth about 15 times as much as the same amount of silver. Although Hamilton understood that adjustment might be needed from time to time as precious metal prices fluctuated, he believed that if the nation's unit of value were defined only by one of the two precious metals used for coins, the other would descend to the status of mere merchandise, unusable as a