207] THE FERTILITY OF THE COMMON FIELDS 51 



In the thirteenth century Walter of Henley and the writer 

 of the anonymous Htisbandry are authorities for the opinion 

 that the average yield of wheat land should be about ten 

 bushels per acre/ At Combe, Oxfordshire, about the middle 

 of the century, the average yield during several seasons was 

 only 5 bushels.^ About 1300, the fifty acres of demesne 

 planted with wheat at Forncett yielded about five-fold or 10 

 bushels an acre (five seasons).^ Between 1330 and 1340, 

 the average yield (500 acres for three seasons), at ten 

 manors of the Merton College estates was also 10 bushels.* 

 At Hawsted, where about 60 acres annually were sown with 

 wheat, the average yield for three seasons at the end of the 

 fourteenth century was a little more than yyi bushels an 

 acre.'' 



Statistical data so scattered as this cannot be used as the 

 basis of an inquiry into the rate of soil exhaustion. Where 

 the normal variation from place to place and from season to 

 season is as great as it is in agriculture, the material from 

 which averages are constructed must be unusually extensive. 

 So far as I know, no material in this field entirely satis- 

 factory for statistical purposes is accessible at the present 

 time. There is, however, one manor, Witney, for which im- 

 portant data for as many as eighteen seasons between 1200 

 and 1400 have been printed. A second suggestive source 

 of information is Gras's table of harvest statistics for the 

 whole Winchester group of manors, covering three different 

 seasons, separated from each other by intervals of about a 



* Walter of Henley's Husbandry, together with an Anonymous Hus- 

 bandry, etc., ed. by Elizabeth Lamond (London, 1890), pp. 19, 71. 



' Curtler, Short History of English Agriculture, p. ZZ- 



3 Davenport, Econ. Dev. of a Norfolk Manor (Cambridge, 1906), p. 30. 



* Rogers, History of Agriculture, et£., vol. i, pp. 38-44. 



* Cullum, Hawsted, pp. 215-218. 



