Industrial Revolution sectors of the economy. However, per-capita food supply in Europe was stagnant or declining and did not improve in some parts of Europe until the late 18th century. Industrial technologies that affected farming included the seed drill, the Dutch plough, which contained iron parts, and the threshing machine. Jethro Tull invented an improved seed drill in 1701. It was a mechanical seeder which distributed seeds evenly across a plot of land and planted them at the correct depth. This was important because the yield of seeds harvested to seeds planted at that time was around four or five. Tull's seed
Drill bit panel work. The finished hole can often be made quite smooth and burr-free, especially in plastic. An additional use of unibits is deburring holes left by other bits, as the sharp increase to the next step size allows the cutting edge to scrape burrs off the entry surface of the workpiece. However, the straight flute is poor at chip ejection, and can cause a burr to be formed on the exit side of the hole, more so than a spiral twist drill bit turning at high speed. The unibit was invented by Harry C. Oakes and patented in 1973. It