620 Life and Letters of Francis Oalton 



full of gaps to be filled in later when the required data might be accessible. 

 He always carried such a note-book about with him, when on his travels or 

 visits, and made rapid jottings in it. Often he would start the whole 

 suggestion or idea afresh, sometimes it led up to the subject of a lecture 

 or a paper ; occasionally the matter is merely referred to in a paragraph of 

 one of his publications, although it is far more developed, if disconnectedly, 

 in the note-book. 



To illustrate the whole process I publish here a few extracts from note- 

 books on Eugenics from 1900 onward. Galton is concerning himself with the 

 topic he often talked about — the average value to the State of the child of 

 picked parents. The factors he has in view are: (i) The degree of superiority 

 of the child of superior parents, (ii) The higher wage or income of such 

 child over the average of its class, (iii) These differences which form the 

 additional profit to the State of the child of superior parents, (iv) This 

 additional profit capitalised is what the State ought to be willing to pay in 

 order to obtain such children. 



I have made no attempt to fill in Francis Galton's gaps, although it 

 would in several instances be feasible. I have given these extracts from the 

 note-books simply to illustrate Galton's method of research, but at the same 

 time I have chosen a suggestive topic, of which the general purport is obvious 

 notwithstanding the fragmentary state of the notes. 



The Money Worth to the State of an Infant Male Child of Selected 

 Parents. From the Papers of Sir Francis Galton, F.R.S. 



Dr Farr has discussed this question with high actuarial skill in respect to the child of an 

 ordinary Essex labourer, supposed to work and get on like the average of his class. He 

 compares the present value of the expenditure incurred in his maintenance and that of the 

 wages he will gain wherewith to maintain his own children, and striking a balance finds it 

 <£ to the good. This was in 18 . The figures would now require revision. 



My problem is of the same kind but depends on different data; it deals with the offspring 

 of parents who have been selected for their civic worth at the rate of 1 in 50 or 1 in 20 of 

 their class. In other words 2 per cent, or 5 per cent., as the case may be, have been picked out 

 as the best by the judgment of the selectors, much as the 2 per cent, best pears might be picked 

 out of a basket and charged for as being of a higher grade. It will be convenient to use the 

 term " per cent, selects " with an appropriate figure prefixed, as 2 per cent, selects or 5 per cent, 

 selects, to express both the fact and the rigour of selection. 



In considering the money value of a select we may be guided by the wages he is likely to 

 earn. If say 2 per cent, of the men of his class earn shillings a week, but that the remaining 

 98 per cent, of them earn shillings, then the excess of the former sum, duly capitalised to its 

 value at the time when the calculation is made, represents fairly enough the superior worth of 

 the children of the selects to the average worth of the children of the class*. The actuarial 

 calculation must be difficult and take many things into account on which we need not now 

 dwell, but the general principle will be intelligible from this outline sketch of it. The point 

 immediately in view is that if A be the money worth of a child to the State, it would be good 

 economy to spend any sum less than A in procuring and maintaining such a child, and bad 

 economy to spend more than A. It is clearly important to ascertain the value of A in each 

 particular case. 



* The regression of the children of the selected parents referred to below has here been 

 overlooked. 



