| 释义 |
Turning plow Related to Turning plow: moldboard plow, mouldboard plough, ploughsTurning plowA plow designed to pulverize a ribbon of earth a few inches wide, and turn it over so that surface trash is buried. The turning plow uses a moldboard to do the turning. The moldboard concept was apparently developed in the eleventh century in the temperate region of Europe. By 1200 a.d., European moldboard plows had developed into ponderous wheeled machines drawn by several oxen, and did more stirring than turning. It took until the mid-1700s for moldboards to advance to the point that they would really turn the soil. Even then, there was no standardization of design, nor any real understanding of the principles involved. That came in the 1780s when Thomas Jefferson in the U.S. and James Small in Scotland began mathematical studies of the moldboard shape that eventually led to rather efficient designs. See Walking turning plow. |