British Agricultural Revolution far apart. Alternately seeds could be laboriously planted one by one using a hoe and/or a shovel. Cutting down on wasted seed was important because the yield of seeds harvested to seeds planted at that time was around four or five. The seed drill was introduced from China to Italy in the mid-16th century where it was patented by the Venetian Senate. Jethro Tull invented an improved seed drill in 1701. It was a mechanical seeder which distributed seeds evenly across a plot of land and at the correct depth. Tull's seed drill was very expensive and fragile and therefore
Hammer drill the special "hammer clutch," turning the tool into a conventional drill for wood or metal work. Hammer drills are more expensive and more bulky than regular drills, but are preferable for applications where the material to be drilled—concrete block or wood studs—is unknown. For example, an electrician mounting an electrical box to a wall would be able to use the same hammer drill to drill into either wood studs (hammer disabled) or masonry walls (hammer enabled). Ancient China's principal drilling technique, percussive drilling, was invented during the Han dynasty. The process involved two to six men jumping on a level