The custom of usurers, however, is to renew the note, adding the interest to the face, if unpaid. The mass of bank paper is renewed each ninety days: Compounded four times a year, whether to the same or to another debtor, the result in accretion is the same.
Few realize the rapidity at which a loan increases, accelerating in geometrical progression as time passes. Any loan will double itself at three per cent. in twenty-three and a half years; at seven per cent. in ten and a fourth years, and at ten per cent. in seven and a third years. One dollar loaned for one hundred years, at three per cent., would amount to nineteen dollars; at seven per cent. one thousand dollars, and at ten per cent. thirteen thousand.
The island upon which New York stands was bought from the Indians for the value of twenty-four dollars by Peter Minuits in 1626. Yet, if the purchaser had put his twenty-four dollars at interest, where he could have added it to the principal at the rate of seven per cent., the accumulation would now exceed the total value of the entire city and county of New York.
M. Jennet quotes the elaborate calculation of an ingenious author to show that 100 francs ($20) accumulating at five per cent. compound interest for seven centuries, would be sufficient to buy the whole surface of the globe, both land and water, at the rate of 1,000,000 francs ($200,000) per hectare (nearly four square miles). From this we can gather that $20 at five per cent. compound interest for 700 years, would buy all the earth, mountains, and swamp lands, and water, at $80 per acre.
Another mathematical genius says, had one cent been loaned on the first day of January A.D. 1, interest being allowed at the rate of six per cent. compounded yearly, then 1895 years later—that is on January 1, 1895—the amount due would be