Use
a weighing machine that indicates both weight and the proper selling price for that weight
In The Encyclopedia American, 1903–1905, it was “classified as follows: Platform scales with change of leverage.”1 The price beam and money-value beam are mounted in a frame that slides left and right to change the leverage (lift the small handle on the left and slide the frame). This is how the price per pound is set. No competitors ever used a change-of-leverage mechanism, and within 10 years, it was surpassed by other technologies.
The total capacity is 100 pounds (45 kg), which was a huge market advantage because other price computing scales only went up to 10 pounds at the most.
The price beam and the additional weights have two graduations for prices, and the money-value beam also has two graduations―in all cases, one being four times the other (for example, see the photo of the weights). The grocer either used the lower amounts on both the beams and the weights, or the grocer used the upper amounts for all readings to make it work.
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