Jethro Tull (agriculturist) the seed so that it could grow. Before the introduction of the seed drill, the common practice was to plant seeds by broadcasting (evenly throwing) them across the ground by hand on the prepared soil and then lightly harrowing the soil to bury the seeds to the correct depth. In his 1731 publication Tull described how the motivation for developing the seed-drill arose from conflict with his servants. He had struggled to enforce his new methods upon them, in part because they resisted the threat to their position as labourers and their skill with the plough. Jethro Tull invented some
Drill bit shank shank was common before 1850, and is still in production. At first, the tapered shank was just rammed into a square hole in the end of the drill. Over time, various chuck designs have been invented, and modern chucks can grasp and drive this shank effectively. It has been difficult to find a reference to the included angle of the taper, but 7 different bits were measured, and they all had an included angle of 8 ± 0.25 degrees. The straight shank is the most usual style on modern drill bits, by number manufactured. The whole of the drill bit,