Sec. 2] SUMMARY OF PART III 305 
The diagram shows, in the second place (tracing it for- 
ward chronologically), that the capital-value alternately 
rises and falls, rising in anticipation of approaching income 
and falling as the installments of this income are, like cou- 
pons, successively detached from capital. The alternate rise 
and fall of the capital curve may be equal, each to the other, 
indicating that the income is “standard”; or the former 
  
  
  
Fic. 14. 
or the latter may be the greater, indicating respectively 
that the income is above or below standard. 
If any installment of income is negative —in other 
words, is not strictly income, but outgo — we need simply 
to reverse the direction of one of the teeth, as in Figure 
15. In this case the capital-value is simply the discounted 
value of the future income less that of the outgo. 
§3 
As we have seen, if we trace th 
curve backward in time from the 
to the beginning of the investmen 
xX 
e entire history of a capital 
last installment of income 
t or enterprise, the curve