APPENDIX TO CHAPTER XIII 377
The decrease in capital-value of the annuity, which has been
represented by the approach of CE to the horizontal line DE
above it, is better represented, however, by inverting CE to
the position AB, in order that the capital-value may be repre-
sented, as in our previous examples, by the distance from the
D E
TT
Fic, 41.
horizontal line AB below it. This change is accomplished
in Figure 40. The value of the annuity taken after each
installment of income is represented by the ordinate, as mA’,
of the curve KB, and the value just before an installment
is represented by the ordinate, as nd", of a point above this
curve a distance equal to that installment. The value at inter-
follows a discount curve, as mn, be-
The result is that the capital-value
g to the steps, or teeth, shown in the
mediate points evidently
tween these two points.
will rise and fall accordin
diagram.
As the income items
come more frequent and smaller, and disappear when the flow
of income is continuous, as represented in Figure 41, where the
become more numerous the teeth be-
— SRE TRS RR