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Rod (length)
The rod, perch, or pole (sometimes also lug) is a surveyor's tool and unit of length of various historical definitions, often between approximately 3 and 8 meters (9 ft 10 in and 26 ft 2 in). In modern US customary units it is defined as US survey feet, equal to exactly of a surveyor's mile, or a quarter of a surveyor's chain ( yards), and is approximately 5.0292 meters. The rod is useful as a unit of length because whole number multiples of it can form one acre of square measure (area). The 'perfect acre' is a rectangular area of 43,560 square feet, bounded by sides 660 feet (a furlong) long and 66 feet wide (220 yards by 22 yards) or, equivalently, 40 rods and 4 rods. An acre is therefore 160 square rods or 10 square chains. The name ''perch'' derives from the Ancient Roman unit, the ''pertica''. The measure also has a relationship with the military pike of about the same size. Both measures date from the sixteenth century, when the pike was still ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pole (surveying)
In surveying, a pole is bar made of wood or metal and normally held vertical, upon which different instruments can be mounted: a prism, a GPS device, etc. It may be manufactured with a predetermined length (e.g., 2 meters) or may be graduated for different heights or stages. Technology advances have introduced tilt-compensation capability into survey poles, that allow the surveyor to measure points above ground or when the pole is off-vertical. References- See also * Level staff {{short description, Graduated rod used to measure differences between heights A level staff, also called levelling rod, is a graduated wooden or aluminium rod, used with a levelling instrument to determine the difference in height between points ... Surveying instruments {{civil-engineering-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
