In today's excerpt - the plow:
"According to Robert Temple in his book, The Genius of China, a history of Chinese science and technology published in 1998, the Chinese invented the moldboard plow by the third century B.C. Made of cast iron, the plowshare was shaped like a V, with the blade carving into the ground and the two arms arcing away like gull wings. Because the arms were curved, they turned the earth away from the blade, which both reduced friction and more effectively plowed the soil. (The "moldboard" is the curved plowshare; the name comes from mold, the Old German word for soil.)
"The design of the moldboard plow is so obvious that it seems incredible that Europeans never thought of it. Until the Chinese-style plow was imported in the seventeenth century, farmers in France, Germany, Italy, the Netherlands, and other states labored to shove what amounted to a narrow slab of metal through the earth. 'The increased friction meant that huge multiple teams of oxen were required, whereas Chinese plows could make do with a single ox,' Temple explained. The European failure to think up the moldboard, according to science historian [Richard] Teresi, was 'as if Henry Ford designed the car without an accelerator, and you had to put the car in neutral, brake, and go under the hood to change speed. And then we did this for 2,000 years.'
"European agricultural production exploded after the arrival of the moldboard plow. The prosperity this engendered was one of the cushions on which the Enlightenment floated. 'So inefficient, so wasteful of effort, and so utterly exhausting' was the old plow, Temple wrote, 'that this deficiency of plowing may rank as mankind's single greatest waste of time and energy.' Millions of Europeans spent centuries behind the plow, staring at the blade as it ineffectively mired itself in the earth. How could none of them have thought of changing the design to make the plow more useful?"
Charles C. Mann , 1491: New Revelations of the Americas Before Columbus, Vintage, Copyright 2005, 2006 by Charles C. Mann, p. 250