Inventions that changed the world: the bearing.
It may seem that the bearings is a product rich in technological inventions of the 18th century, because commencement of commercial production and sale of rolling bearings, resembling modern samples started from this time. This element, which provides a soft rotation of nodes was included in the design of the carts and throwing military equipment. But if you dig deeper, it becomes clear that the bearing is even more ancient invention than the proverbial wheel.
Modern bearings, of course, are very different from the pre-image: making strong alloys is used, computer control on the quality of processing of materials allows to achieve ideal soft travel and resistance to the greatest loads. The bearings allow the work of giant oil rigs and complex nano-robots. But in fact, it is the same bearing, which was rolled out last stone to the top of the pyramid of Cheops.