accurate grinding
41Faceting machine — A faceting machine is broadly defined as any device that allows the user to place and polish facets onto a mineral specimen. Machines can range in sophistication from primitive jamb peg machines to highly refined, and highly expensive,… …
42Spirit rover — (MER A) Artist s concept of Rover on Mars Operator NASA Mission type Rover Launch date …
43Timeline of Islamic science and engineering — This timeline of Islamic science and engineering covers the general development of science and technology in the Islamic world during the Islamic Golden Age, usually dated from the 7th to 16th centuries.From the 17th century onwards, the advances …
44Mandrel — For other uses, see Mandrel (disambiguation). Not to be confused with Mandrill (the primate species). Old shop made mandrel for turning hollow objects on an engine lathe …
45Chuck (engineering) — Self centering three jaw chuck and key with one jaw removed and inverted showing the teeth that engage in the scroll plate. The scroll plate is rotated within the chuck body by the key, the scroll engages the teeth on the underside of the jaws… …
46Ceramography — is the art and science of preparation, examination and evaluation of ceramic microstructures.[1] Ceramography can be thought of as the metallography of ceramics. The microstructure is the structure level of approximately 0.1 to 100 µm, between… …
47Europe, history of — Introduction history of European peoples and cultures from prehistoric times to the present. Europe is a more ambiguous term than most geographic expressions. Its etymology is doubtful, as is the physical extent of the area it designates.… …
48Tape measure — plastic tape measure (metric) Self retracting tape measure (imperial) …
49Lapping — is a machining operation, in which two surfaces are rubbed together with an abrasive between them, by hand movement or by way of a machine.This can take two forms. The first type of lapping (traditionally called grinding), typically involves… …
50Brown, Joseph Rogers — born Jan. 26, 1810, Warren, R.I., U.S. died July 23, 1876, Isles of Shoals, N.H. U.S. inventor and manufacturer. He perfected and produced a highly accurate linear dividing engine in 1850, and then developed a vernier caliper and also applied… …
