rod: see English units of measurement.

lightning rod, a rod made of materials, especially metals, that are good conductors of electricity, which is mounted on top of a building or other structure and attached to the ground by a cable. By virtue of its position, shape, and conductivity the rod attracts lightning discharges much more readily than the building on which it is mounted. When struck, the connecting cable carries the discharge safely into the ground, preventing any damage to the building. Benjamin Franklin, in his kite experiment (1752), proved that lightning and electricity are identical and subsequently invented the lightning rod.

divining rod or dowser, stick used in searching for underground water or minerals. This form of divination is still in common use in many parts of the world. The instrument is typically a forked twig. The operator holds the forked ends of the twig close to his body, with the stem pointing forward. When he walks over a spot under which water or the desired mineral lies, the stem of the divining rod is supposedly pulled down. Impartial research, however, has indicated that successes in this method result mostly from chance and possibly also from a heightened sensitivity to visual cues of which the diviner is unaware.

Laver, Rod (Rodney George Laver), 1938-, Australian tennis player. He left school at age 15 to pursue tennis and in 1962 became the first male grand-slam winner in tennis since Don Budge in 1938. Noted for his extraordinarily powerful serve, Laver turned professional in 1962. He won the grand slam again in 1969, the only person ever to do so twice. In 1971 he became the first professional tennis player to pass the $1 million mark in total earnings.

Aaron's-rod, popular name for several tall-flowering, infrequently branching plants, such as goldenrod and mullein. The name is an allusion to the rod that Aaron placed before the ark and that miraculously blossomed and bore almonds.

Automobile rebuilt or modified for high speed, fast acceleration, or sporty appearance. A wide range of automobiles may be called hot rods, including some of those used in drag racing as well as those used in recreational cruising. They may be composed of used or new parts. Some are intended primarily for exhibition.

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Arrangement of mechanical parts used to obtain a reciprocating straight-line motion from a rotating shaft. It serves the same purpose as a slider-crank mechanism and is particularly useful when the required stroke of the reciprocating motion is small in comparison with the dimensions of the driving shaft. Because an eccentric can be attached anywhere along a shaft, it is unnecessary to form any part of the shaft into a crank. Eccentrics are seldom used to transmit large forces because friction loss would be high; they are commonly used to drive the valve gears of engines.

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(born Aug. 9, 1938, Rockhampton, Queen., Austl.) Australian tennis player. He joined Australia's Davis Cup team when he was 18 years old and remained on the squad until 1962. Nicknamed “Rocket,” he became the second male player (after Don Budge) to win the grand slam (1962) and the first to repeat the feat (1969). He turned professional in 1963 and in 1971 became the first tennis player to surpass $1 million in career prize money.

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