Why? Because they looked at the curve and said, if the population keeps growing at this rate, to move the population of New York around, they would have needed six million horses, and the manure created by six million horses would be impossible to deal with.
Hvorfor? Fordi de kiggede på kurven og sagde, hvis befolkningen bliver ved  med at vokse i samme takt, for at flytte New Yorks befolkning rundt, ville de have brug for seks millioner heste, og gødningen der ville blive  skabt af seks millioner heste ville være umulig at håndtere.