of the earth, sparsely inhabited and accessible with difficulty. And at other times, nomadic groups known as 'yeggmen' visited the banks, opened the vaults by force, and departed, carrying with them the contents.

"But to return to our subject. In the year 1921, one of these numerous John Joneses performed an apparently inconsequential action which caused the name of John Jones to go down in history. What did he do?

"He proceeded to one of these banks, known at that time as 'The First National Bank of Chicago,' and deposited there, one of these disks—a silver Dollar—to the credit of a certain individual. And this individual to whose credit the Dollar was deposited was no other person than the fortieth descendant of John Jones who stipulated in paper which was placed in the files of the bank, that the descendancy was to take place along the oldest child of each of the generations which would constitute his posterity.

"The bank accepted the Dollar under that understanding, together with another condition imposed by this John Jones, namely, that the interest was to be compounded annually. That meant that at the close of each year, the bank was to credit the account of John Jones's fortieth descendant with three one-hundredths of the account as it stood at the beginning of the year.

"History tells us little more concerning this John Jones—only that he died in the year 1931, or ten years afterward, leaving several children.

"Now you gentlemen who are taking mathematics under Professor L127M72421Male, of the University of Mars, will remember that where any number such as X, in passing through a progressive cycle of change, grows at the end of that cycle by a proportion p, then the value of the original X, after n cycles, becomes X(1 + p)n.

"Obviously, in this case, X equalled one Dollar; p equalled three one-hundredths; and n will depend upon any number of years which we care to consider, following the date of deposit. By a simple calculation, those of you who are today mentally alert can check up the results that I shall set forth in my lecture.

"At the time that John Jones died, the amount in the First National Bank of Chicago to the credit of John Jones the fortieth, was as follows."

The professor seized the chalk and wrote rapidly upon the oblong space:

"The peculiar sinuous hieroglyphic," he explained, "is an ideograph 

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