STANDARD OF COMPARISON. 85 



proximately the latitude in which the majority of these famous men 

 were born. If there be any difference, the Redfields were born 

 slightly further north. These Redfields were neither eminent 

 statesmen nor day laborers, but average examples of New England 

 citizens. They were largely farmers, with a sprinkling of mer- 

 chants, sailors and professional men. Many of them, like other 

 Americans of the eighteenth century, married early and produced 

 large families, and consequently their births extended over a wide 

 range and exhibited nearly all possible combinations. 



HOW STANDARD SCALE IS MADE. 



In making up my standard for comparison I have taken only 

 those cases in which the family record was complete, and have ex- 

 cluded every family in which one or more births could not be 

 accurately determined. By adding a few births occurring in the 

 first decade of the nineteenth century I managed to obtain the ages 

 of the fathers for 240 births, and the ages of the mothers for 180 

 births. I then divided these births into ten equal groups, which I 

 tabulated as follows: 



TABLE I. 



AGES OF PARENTS AT BIRTH OF THEIR CHILDREN. 



(Ten per cent in each class.) 



Fathers. Class. Mothers. 



Under 24-6 a Under 22-0 



Between 24-6 and 27-1 b Between 22-0 and 24-1 



" 27-1 and 28-1 1 c 24-1 and 25-9 



" 28-1 1 and 30-9 d 25-9 and 27-5 



" 309 and 32-8 e 27-5 and 29-2 



32-8 and 34-9 E 29-2 and 31-0 



34-9 and 37-3 D 31-0 and 33-7 



37-3 and 40-0 C 33-7 and 35-10 



40-0 and 44-6 B 35-10 and 39-10 



Over 44-6 A Over 39-10 



