A friend of mine seems to think that the wheelbarrow is one of the most important inventions for the common man to ever be created. I also like the wheelbarrow but more on the scale that it can really help an individual get a lot more done than if they had a more conventional cart or just bare hands. So lets speculate a European trader returns from the Tang Dynasty with little to show for his effort. Wondering just how he can turn his experience into a way to make money. Remembering assisting a farmer who had given him a room for the night fix his one wheeled cart and thinking it a novel machine. Wondering why they were not in use in his homeland? They seemed easy enough a concept. He makes a prototype and gives it to a farmer in return for feedback. Then refines the design some and goes about selling them. This would be at least 300 years earlier than the Wheelbarrow appears in otl, lets say this is taking place in Northern Italy. Will the wheelbarrow spread from here? How does this change history if at all? Just the day to day for common people and merchants or does it have larger ramifications?