The 12th century saw the development of tilling and milling technologies in the West, but there is less evidence for similar Byzantine innovation. Western advances like the windmill were adopted by the Byzantines, but, unlike the West, Arabic numerals were not yet implemented for double-entry book-keeping. There are illustrations of agricultural implements from illuminated medieval manuscripts of Hesiod's Works and Days including the wheel, mortar, pestle, mallet and some parts for carts and soleard plough, but, even centuries later, neither the plough nor wheeled cart were widely in use, possibly because of the nature of the Pontic terrain.