Nature of the Statistical Data available. 79 



and Wales. For Scotland, there were the returns collected 

 by the Highland Society for 1854, 1855, 1856, and 1857; 

 but for the two years prior to 1854, and for the years subse- 

 quent to 1857, down to 1865 inclusive, estimates only were 

 available. For Ireland, returns were available throughout. 

 From 1866 onwards the " Agricultural Returns " have given 

 the much-needed official information as to the acreage of 

 wheat in the United Kingdom. 



2. The only returns or official estimates as to the average 

 yield of wheat per acre were for Scotland for four years, and 

 for Ireland for each year within the period of the inquiry. 

 For England and Wales, comprising from 85 to 90 per cent, 

 of the total area under wheat, it was necessary, in the 

 absence of any official information whatever, to fall back 

 upon the average produce per acre each year of the selected 

 plots at Eothamsted, in the manDer already described. 



3. The aggregate home produce is deduced from a know- 

 ledge of the acreage under crop, combined with a trustworthy 

 estimate of the average yield per acre, whilst the amount 

 available for consumption is arrived at by deducting from 

 the total produce the quantity annually returned to the land 

 as seed. On adequate grounds it is assumed that 2| bushels 

 per acre are required for this latter purpose. 



4. The imports have throughout been taken from the 

 Eeturns for the United Kingdom, either of the net imports 

 of wheat and wheat flour, or of the imports and exports from 

 which the net imports can be calculated. Moreover, the net 

 imports have been calculated, not for the calendar years, but 

 for the harvest years, that is, from September 1 of one year to 

 August 31 of the next. 



5. The figures as to population are taken from the esti- 

 mates of the Begistrar-G-eneral. The middle of the calendar 

 year being the end of June, and the middle of the harvest 

 year the end of February, the plan adopted has been to add 

 to the number officially recorded for the preceding mid- 

 summer two-thirds of the difference between that figure 



