226 NATURE OF CAPITAL AND INCOME [Cmar. XIII 
small sum, such as $1000, if allowed to accumulate, let us 
say, at 4 per cent for 1000 years, could never actually 
attain the theoretical magnitude. This is evident from 
the fact that the theoretical sum would then amount to 
over $100,000,000,000,000,000, which is so far in excess of 
the total value of capital on this planet, as to be out of 
the range of possibility. The reason the sum would fail 
to accumulate as fast as theoretically required, aside from 
fortuitous losses, lies in the reduction of the rate of in- 
terest which the very accumulation would bring about. 
The administrators of such a fund, as the centuries passed 
by, would find it increasingly difficult to obtain fields in 
which to invest it, and their effort so to invest would have 
the same effect in reducing the rate of interest realized on 
the investments as is now felt by the national banks in 
their pressure to buy government bonds.