Seed drill China, and later a seed drill by Jethro Tull that was influential in the growth of farming technology in recent centuries. Even for a century after Tull, hand sowing of grain remained common. In older methods of planting, a field is initially prepared with a plow to a series of linear cuts known as "furrows". The field is then seeded by throwing the seeds over the field, a method known as "manual broadcasting". The seeds may not be sown to the right depth nor the proper distance from one another. Seeds that land in the furrows have better protection from
Down-the-hole drill for the DTH method underground, where the direction of drilling is generally upwards instead of downwards. In "DTH" drilling, the percussion mechanism – commonly called the hammer – is located directly behind the drill bit. The drill pipes transmit the necessary feed force and rotation to hammer and bit plus compressed air or fluids for the hammer and flushing of cuttings. The drill pipes are added to the drill string successively behind the hammer as the hole gets deeper. The piston strikes the impact surface of the bit directly, while the hammer casing gives straight and stable guidance of the