Technology became more and more influenced by science, starting a cycle of mutual development. Innovations continued by way of the Middle Ages with the introduction of silk production , the horse collar, and horseshoes. Simple machines were mixed into more difficult instruments, such as the wheelbarrow, windmills, and clocks. A system of universities developed and spread scientific ideas and practices, including Oxford and Cambridge. Continuing enhancements led to the furnace and bellows and offered, for the first time, the ability to smelt and forge gold, copper, silver, and lead – native metals present in comparatively pure form in nature. The …