“Do not disturb me,” he said. “I am calculating the interest which I would receive if I were to inherit all of Mr Vanderbilt’s money and estates, and how much, with the compound interest added to it, it would amount to in one hundred years, and I want to see whether this would be enough to enable me to live comfortably in my old age. I have now been over this calculation for many years, but I must begin it again, because the value of the stocks has again changed, and there is a difference in the amount of the interest.” I was surprised to hear that a person of such a beggarly appearance should have such excellent financial prospects, and I said: “When do you expect to make that inheritance, and could you not get now some money on credit on the strength of your prospective income?” To this the ghost replied: “Alas, no! I have no prospect of making any inheritance whatever, and there is no one who would lend me a penny; but it is such a comfort to know how much money I might enjoy if I had it, and what an amount of interest the capital would bring if I were in possession of it.” “And could you not do some work for the purpose of earning some money?” “Alas, no! I have no time for that; I must finish this calculation first.” “But what good will it do to you,” I asked, “to know all that stuff, as long as you are in such a state of poverty?” The ghost shivered. He looked at me scornfully, and said in an angry tone-- “Knowledge is power! Do not waste my precious time. Begone!”