Part 17 (2/2)
We will further take 20 years as being 4.5 years earlier than the average time of marriage, and 29 years as 4.5 years later than it, so that the length of each generation of the A group will be 27 years, and that of the B group will be 36 years. All these suppositions appear to be perfectly fair and reasonable, while it may easily be shown that any other suppositions within the bounds of probability would lead to results of the same general order.
The least common multiple of 27 and 36 is 108, at the end of which term of years A will have been multiplied four times over by the factor 1.5, and B three times over by the factor 0.85. The results are given in the following Table:--
Number of Female Descendants who themselves become Mothers.
====================================================================== After Number
A
B
of Years
Of 100 Mothers whose
Of 100 Mothers whose
as below.
Marriages and those of
Marriages and those of
their Daughters all take
their Daughters take
place at the Age of
place at the Age of
20 Years.
29 Years.
---
----
(Ratio of Increase in
(Ratio of Decrease in
each successive
each successive Generation
Generation being 1.15.)
being 0.85.)
-------------+--------------------------+----------------------------
108
175
61
216
299
38
324
535
23
======================================================================
The general result is that the group B gradually disappears, and the group A more than supplants it. Hence if the races best fitted to occupy the land are encouraged to marry early, they will breed down the others in a very few generations.
MARKS FOR FAMILY MERIT
It may seem very reasonable to ask how the result proposed in the last paragraph is to be attained, and to add that the difficulty of carrying so laudable a proposal into effect lies wholly in the details, and therefore that until some working plan is suggested, the consideration of improving the human race is Utopian. But this requirement is not altogether fair, because if a persuasion of the importance of any end takes possession of men's minds, sooner or later means are found by which that end is carried into effect. Some of the objections offered at first will be discovered to be sentimental, and of no real importance--the sentiment will change and they will disappear; others that are genuine are not met, but are in some way turned or eluded; and lastly, through the ingenuity of many minds directed for a long time towards the achievement of a common purpose, many happy ideas are sure to be hit upon that would not have occurred to a single individual.
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