CHAPTER VII. 



GREAT MEN OF ANCIENT TIMES. 



Before we proceed to investigate the ancestry of great men of 

 all ages from all countries, it is proper that an explanation be given 

 of the method by which results are arrived at. In some cases the 

 date of the birth of the great man is given and that of his father is 

 also given, in which event we have all the data necessary to locate 

 exactly the great man's birth-rank. In a great many cases, how- 

 ever, the father's birth is not given, but there is such collateral 

 evidence that will enable us to locate it pretty accurately and thus 

 arrive at results that are without sensible error. The manner in 

 which these estimates are made may be best illustrated by an 

 example. 



METHOD OF ESTIMATING. 



In the Cyclopedia I find that de Jussieu is the name of a French 



family of natural philosophers, who have been styled the "botanical 



dynasty" of France. The founder of the family, whose birth is 



not recorded, had a son Antoine, born in 1686, a son Bernard, born 



in 1699, and a third son whose name and birth are not given. This 



unrecorded brother had a son Antoine Laurent, born in 1748, and 



another but unrecorded son. This last unrecorded person had a 



son. Laurent Pierre, born in 1792. The problem is to construct 



an ancestry for Laurent Pierre de Jussieu, the date of the birth of 



not a single ancestor of whom is given. To do this a diagram is 



constructed as follows: 



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