A QUESTION OF POPULATION 165 



On calculating, it will be found that the twenty-fourth 

 term of the progression i, 2, 4, 8, 16, etc., is 8,388,608, or 

 $83,886.08, a sum which is more than any horse, even the 

 best Arabian, was ever sold for. 



Had the price of the horse been fixed at the value of all 

 the nails, the sum would have been double the above price 

 less the first term, .or $167,772.15. 



A QUESTION OF POPULATION 



HE following note on the result of unrestrained 

 propagation for one hundred generations is taken 

 from "Familiar Lectures on Scientific Subjects," 

 by Sir John F. W. Herschel : 



For the benefit of those who discuss the subjects of 

 population, war, pestilence, famine, etc., it may be as well 

 to mention that the number of human beings living at the 

 end of the hundreth generation, commencing from a single 

 pair, doubling at each generation (say in thirty years), and 

 allowing for each man, woman, and child, an average space 

 of four feet in height and one foot square, would form a 

 vertical column, having for its base the whole surface of 

 the earth and sea spread out into a plane, and for its height 

 3,674 times the sun's distance from the earth ! The num- 

 ber of human strata thus piled, one on the other, would 

 amount to 460,790,000,000,000. 



In this connection the following facts in regard to the 

 present population of the globe may be of interest : 



The present population of the entire globe is estimated 

 by the best statisticians at between fourteen and fifteen 



