Price of Wheat , over 40 Harvest-Years , 1852-3 to 1801-2. 83 
5 - 5 bushels during the second eight years, 18G0-G1 to 1867-68 ; 
and in the subsequent annually published estimates that figure 
was adopted up to 1879-80 inclusive. But, on the review of 
the estimates and their results in our second paper, in 1880, the 
consumption was estimated at 5'6 bushels during the third eight 
years, and 5 - 65 subsequently ; and this last figure has been 
adopted since that date, that is, from 1876-77 up to the present 
time. The correctness of this estimate in the past, and its con- 
tinued applicability in the future, will be considered farther on. 
Reconsideration of the Data. 
From the foregoing review it results that, so far as the area 
under the crop, and the amount of the imports, are concerned, 
the same data must be relied upon as heretofore. But, in regard 
to the average produce of wheat per acre over the United 
Kingdom each year, the estimates of the population each year, 
and those of the consumption per head of the population, the 
basis of the estimates, and the results arrived at, will now, after 
the experience of forty years, and with the further information 
available, be submitted to careful re-examination, and be con- 
firmed or corrected accordingly, as the case may be. 
The Estimates of the Average Produce of Wheat per Acre 
in the United Kingdom each Year. 
We will first consider the validity of the estimates of the 
average yield of wheat per acre over the United Kingdom each 
year. As already stated, they have been founded on the average 
produce obtained on certain selected plots in the field at Rotham- 
sted, which is now growing the crop for the fiftieth year in 
succession — without manure, with farmyard manure, and with 
various artificial manures. There has been no change in the 
treatment of either the unmanured or the farmyard manure plot 
since the commencement of the experiments in 1843-44. There 
were, however, some changes in the manures applied to the various 
artificially manured plots during the first eight years, that is, to 
1850-51 inclusive. But, for all the subsequent crops, from 1852 
up to the present time, two of the three selected artificially- 
manured plots have, respectively, received exactly the same 
manure each year, and the third has done so for a period of 
thirty years from 1854-55 to 1883-84 ; after which, from 
1884-85 and since, another plot has received the same manures, 
and from that time the results obtained on it have been brought 
into the calculation, as further explained below. . . . 
