True but. Before gasoline delivery trucks had powered meters for accurate delivery amounts, they were used to calculate the number of gallons being moved from the truck into the customers storage tank. The old trucks had a cast iron wheel inside the rear doghouse. It was marked in five gallon increments. Each can had a brass ear that stood at the top of the can, just below the lid. It accurately stood for either five or ten gallons, depending on the can. The driver gravity feed the can up to that point. Turned the delivery counting wheel up to match the can. Then they dumped it into the holding tank. At the end he simply added up the figure and the customer knew what he got. Just a manual way to make accurate deliveries before machination took over. Paul
