Scythe
horse drawn hoe
horse drawn seed drill
plough
Thousands of inventions surface daily, most are never entertained for mass production. A simple invention that could be done in just four days is a cell phone application to read the tone of your voice and select the right song to play for that particular mood.
Four Modernizations
A four input and gate is a logic gate with four inputs. The output is true only when all four inputs are true.
There four p's in software engineering. The four p's are people , product, process, project.
Pick any four from the attached link.
the cotton gin the sewing machine the steel plow the mechanical reaper
there is analytic geometry and logarithms. Pendulum clock by huygens. Some of the inventions during the Scientific Revolution included the theremometer, barometer, microscopes, and the telescope. There were many more inventions during the revolution.
The European Big Four that was the backbone of opposition to France included Austria, Prussia, Russia and the United Kingdom.
"Four Great Inventions:"GunpowderPaperPrintingCompassOthers:ForkBank notes (paper currency)CoffinCast IronIncenseBell
The agricultural revolution, expansion of cities, advances in transportation networks and the creation of new business techniques (The west- encounters and transformations P.304)
kite crossbow compass paper
It didn't happen in a single year, but a gradual change of many things over a period of time. The British Agricultural Revolution describes a period of development in Britain between the 17th century and the end of the 19th century, which saw a massive increase in agricultural productivity and net output. This in turn supported unprecedented population growth, freeing up a significant percentage of the workforce, and thereby helped drive the Industrial Revolution. How this came about is not entirely clear. In recent decades, enclosure, mechanization, four-field crop rotation, and selective breeding have been highlighted as primary causes, with credit given to relatively few individuals.
papermaking, compass, gunpowder, and printing
Among many inventions that have helped the US, a few stand out as "remarkable". The four are:* telephone * airplane * phonograph and * motion picturesOther views exist of course. The question requires a subjective answer.
domestic industrial commercial agricultural.
bhel
There are many inventions. Just four of them (randomly) are: 1445-printing press 1485 parachute 1495 toothbrush 1500 flushing toilets