中世纪小麦的度量衡与参考价格

摘自《透视大气中二氧化碳浓度增加对作物产量的相对影响》（Perspective on the relative insignificance of increasing atmospheric CO2 concentration to crop yield）

Measures of wheat harvested and the area of fields varied significantly over time and location in Britain (Harrison, 1985a, b; John, 1989). The following definitions were adopted in this analysis. A medieval (pre-1600) bushel was about 22.4 kg, whereas a modern (post-1600) bushel is 27.2 kg. A medieval quarter of wheat was about 179 kg (8 medieval bushels). For British wheat, the hundredweight (cwt) is about 50.8 kg (112 pounds).

《WAGES AND PRICES IN ENGLAND, 1261-1701.》