Glossary E – J
*terms marked with an asterisk appear in this glossary
END FRICTIONS — see ANTI-FRICTION PLATES.
EQUAL-ARM BEAM — a beam in which the end pivots are at equal distances from the fulcrum,* Fig. 3a (Glossary A–B). See also UNEQUAL-ARM BEAM.
ESSAY BALANCE — see ASSAY BALANCE.
ESTIMATING SCALE — a scale for ascertaining the weight of a large quantity of goods by weighing a small sample, for example, grain scales,* paper scales,* etc. See also COMPUTING SCALES, COUNTING SCALES.
EVEN-ARM SCALE — a scale with an equal-arm beam.*
FAN CHART — a graduated card* in the form of a fan, or segment of a disc, Fig. 25.
FAN SCALE — a scale with a fan chart,* Fig. 25.
FAST — a scale is said to be 'fast' when the weight indicated is more than the true weight. See also SLOW.
FIDUCIAL EDGE - see READING EDGE.
FLAG — a small flag-shaped weight on a spindle above the center of the beam of a precision balance. The flag can be swung to any desired position for minute adjustment of the balance, Fig. 26.
FLEXURE PIVOT, FLEXURE PLATE — a pivot* made from a thin flat strip of metal, which relies on the bending, or flexing, of the metal for its rotation. Also called a PLATE FULCRUM (USA). Fig. 27.
FLEXURE RESISTANT — a flat spring used in certain types of spring balance. For example, in letter scales and stylus balances, Fig. 28. The spring may form one of the stays of a half-Roberval* system.
FOLDING GOLD BALANCE — a coin scale in a narrow box, which usually springs up into position when the lid is opened, Fig. 30. Also called a LANCASHIRE GOLD BALANCE (18th c.) and, misleadingly, an AUTOMATIC BALANCE (by Sheppard & Musham).
FORKS — see SHEARS.
FRACTION BAR — a secondary beam, or side beam,* parallel to the main beam, and used to weigh fractional units. The capacity is usually equal to the difference between graduations on the main beam, Fig. 31.
FRACTION WEIGHTS — thin sheet metal weights denominated in fractions of a weight unit, e.g., 1/2, 1/4, 1/8, 1/16 carat, or in decimal fractions: 0.5, 0.2, 0.1, 0.05 gram, etc. See also GRAIN WEIGHTS.
FRICTIONS — see ANTI-FRICTION PLATE.
FRICTION PLATE — see ANTI-FRICTION PLATE.
FULCRUM — the point around which a beam, or other part, rotates; the main pivot.*
GALLOWS — see SHEARS.
GAUSS WEIGHING; GAUSSIAN WEIGHING — see TRANSPOSITION WEIGHING.
GOLD BALANCE — a scale for weighing gold coins, gold bullion or gold dust etc. See also FOLDING GOLD BALANCE.
GOODS PAN, GOODS PLATE — the receptacle onto which a load is placed for weighing. Also called a COMMODITY PLATTER (USA). See also WEIGHT PAN, PAN, PLATE.
G.P.O.— General Post Office. These initials were marked on scales and weights used by the British postal authorities, often in conjunction with an arrow signifying government property.
GRADUATIONS — the main marks on a chart,* beam,* quadrant,* etc., which denote the weight, price, or number. See also DIVISIONS.
GRAIN SCALE — a scale for ascertaining the weight of a large volume of grain, beans, peas, etc., by weighing a small sample. A form of estimating scale.* In England, the graduations are in pounds per bushel. Also called a CHONDROMETER, CORNOMETER, or CORN SCALE. See also GRAIN TESTER.
GRAIN TESTER — a form of grain scale* which also indicates the percentage loss in weight when grain husks, dirt, etc. have been removed, Fig. 29. See also PERCENTAGE SCALE.
GRAVITY BALL, GRAVITY WEIGHT — a weight on a threaded rod above the center of a beam and used to raise or lower the center of gravity. A means of adjusting the sensitivity,* usually on precision balances, Fig. 26.
GROSS WEIGHT — the weight of a quantity of goods including the container, wrapper, etc. Gross weight = Net weight* + Tare weight*. See also NET WEIGHT, TARE WEIGHT.
GUARD LINK — see PENDANT.
HALF-ROBERVAL — a scale which has a single pan supported above the beam by a leg* and stay,* as in the Roberval* principle, combined with one of the various resistants* e.g., half-roberval and steelyard; half-Roberval and pendulum, etc., Fig. 32. Also called a SEMI-ROBERVAL.
HANDLE — an ancient English term for the shears,* on small hand-held scales.
HANGER — a rigid rod hanging from a scale beam and used to suspend a pan,* plate,* weights, or counterpoise.* The hanger may be STRAIGHT, CURVED, or CRANKED, Fig. 34, or may be a double sided STIRRUP HANGER, or BOW.
HANGING SCALE — a scale designed to be suspended from above, and which has its goods pan* hanging below.
HARP TOP — the decorative loop at the top of the column* supporting a scale beam, Fig. 34.
HOOK END — a Medieval beam end in the form of a hook, from which the cord ring was suspended, Fig. 6, No. 4 (Glossary A–B).
HUCKSTER SCALE — a small un-compensated spring balance used by green grocers, traveling traders, etc. (USA).
HYDROSTATIC SCALE — a scale incorporating a liquid for supporting or counterbalancing the load. The liquid is used as a resistant* but may also be used as an indicator* simultaneously, Fig. 33.
HYDROSTATICAL SCALE — an 18th-century English term for a form of counterfeit coin detector* or specific gravity scale.* The coin was first weighed in air and then re-weighed when immersed in water, Fig. 35. Buoyancy was counteracted by special water weights placed in the pan above the coin (or by special settings on a steelyard). Counterfeit coins of the correct weight in air were lighter than true gold ones when weighed in water.
INCLINATION BALANCE — see PENDULUM BALANCE.
INDEX — any device, or datum point against which graduation marks are read.
INDICATOR — any device which indicates weights, price, etc. See also POINTER, INDEX.
INTERLEVER — a lever used between a beam and a resistant,* or between other levers, and used to provide the required lever ratio.*
INVERTED ROBERVAL — a scale on the Roberval* principle, but which has the legs and stays* above the beam, Fig. 36. Also known as an IMPERIAL SCALE (UK). The long legs so achieved reduce the wear from side forces acting on the pivots.
INVERTED SWAN NECK END — a beam end curved in the opposite way to a conventional swan neck end.* The tip of the curved part is formed into a continuous knife edge* with which a stirrup hanger* is used, Fig 6. No. 26 (Glossary A–B).
JAPANNED — coated with a hard varnish-like substance fired in an oven and applied to tinware in imitation of Japanese lacquer. It was used on oval metal boxes (and other shapes) for 18th c. and 19th c. English coin scales.
JOCKEY SCALE — a scale adapted for weighing jockeys at race meetings. A form of person scale.*
JOCKEY WEIGHT — see RIDER WEIGHT.