96 Home Produce , Imports , Consumption, and 
and foreign supplies taken together, were comparatively low 
within the five years, the imports not increasing at so rapid a 
rate as previously ; whilst during the last three years, and 
especially in the last harvest-year (1891-2), the imports were very 
much in excess of the requirements. Hence, during the five years, 
the amount of imports to deduct from the requirements for con- 
sumption were comparatively low, leaving, according to the mode 
of calculation, a larger proportion to be apparently derived from 
the home produce ; whilst, over the last three years, the imports 
being undoubtedly in excess of the requirements, deducting them 
from the requirements leaves a too low amount to be credited to 
the home crop. If, however, we take the average for the two 
periods of five and three years together, that is, for the last eight 
years, as shown in the bottom line of the Table, the average 
of the annually adopted estimates, and the result founded on 
consumption and imports, differ by only J of a bushel. 
Finally, taking the result for the total period of forty years 
in each case, the average of the annually adopted estimates, 
and that calculated from consumption and imports, are identical, 
namely 27^ bushels; whilst the actual average produce of the 
selected plots is 27 J bushels. 
So much for the validity, in the past, of the results of the 
selected plots in the experimental field at Rothamsted, as a basis 
for the annual estimation of the yield per acre of the United 
Kingdom. 
We will now consider how far the estimates of the total home 
crop available for consumption arrived at as above, together 
with the actually returned net imports each year, indicate 
amounts consumed per head of the population from home and 
foreign sources respectively, and from the two together, which 
confirm the estimates that have been annually made of the total 
requirement per head of the population. 
Table II. (p. 97) shows, for each of the first four eight-yearly 
periods, for the next five years, and for the total thirty-seven 
years, also for the last three years, and for the total period of 
forty years, the amounts of wheat available for consumption per 
head per annum, from home and from foreign sources respectively, 
and from both together, according to the estimates of the home, 
the actual records of the foreign supplies, and the returns of the 
population, as given in the Appendix-Table I. (p. 132) ; and, in 
the last column of the Table there are given for comparison, the 
averages for each period of the annually adopted estimates of the 
total requirement per head of the population. It should be added 
that, in these calculations relating to our past estimates, the 
