Weights and Measures

THIS IS A LETTER I WROTE TO MY NEPHEW & NIECE, WHEN THEY WERE SMALL. FOUND IT TODAY, AND LEAVING THIS HERE FOR ALL THE CHILDREN IN MY FAMILY, I LOVE.

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I’ve decided that once in a while I will now write to you all while I am away. You all can also write to me if you people feel like. I will write to you on variety of subjects as I feel like and also if there is something that you people want to know from me. This will be basically to do with everyday news, history, geography, religion, science, countries and people etc. Hope this you’ll find useful. There are things that you may not understand today, but may be someday it will help you in future.

Today lets talk of measurements / units in practical terms what they mean.

To start with have you ever thought what it means when you answer questions like –

How tall are you? How much do you weigh? You can find out using weights and measures.

MEASURING LENGTH

Measurements of length tell how tall you are. The inch, foot, yard, and mile are units used for measuring length in the United States. This is called the English measurement system. There are 12 inches in a foot, and 3 feet in a yard. A mile is equal to 5,280 feet.

These are generalized units and have inter-conversions too with the metric system that we sometimes use in India and all the other countries and all scientists and engineers that use the metric system. The centimeter, meter, and kilometer are metric units for measuring length. The metric system is based on units that can be multiplied or divided by 10. A centimeter is one-hundredth of a meter. There are 1,000 meters in a kilometer.

You can measure how tall you are with inches and feet, or centimeters and meters. You also use feet or meters to tell how high a mountain or a building is. You measure longer distances with yards and miles, or meters and kilometers.

There are special units for measuring the length of certain things. For example, the furlong measures lengths in horse races.

MEASURING WEIGHT

If you live in the United States, you can tell how much you weigh using a system of ounces and pounds. There are 16 ounces in a pound. The ton is the measurement for very heavy things, like ships. A ton is 2,000 pounds! The metric system uses grams, kilograms, and metric tons. There are 1,000 grams in a kilogram, and 1,000 kilograms in a metric ton.

You also use weight measurements to tell how much food you are buying. You use ounces and pounds, or grams and kilograms, to weigh potatoes, carrots, meat, and other kinds of food.

There are special units for weighing other things. You use the carat to weigh diamonds and other gemstones. You use a different unit called the karat to measure the purity of gold.

MEASURING LIQUIDS

English units for measuring liquids are the teaspoon, tablespoon, fluid ounce, cup, pint, quart, and gallon. There are 3 teaspoons in a tablespoon, 2 tablespoons in a fluid ounce, 8 fluid ounces in a cup, 2 cups in a pint, 2 pints in a quart, and 4 quarts in a gallon. All those units can be a bit confusing! Metric liquid measurements are simpler. The most common metric units for liquids are milliliters and liters. There are 1,000 milliliters in a liter. You use the same units for all liquids from lemonade to gasoline.

The barrel is a special unit for liquids. It is used to measure large amounts of liquid such as oil. A barrel of oil has 42 gallons.

HISTORY

Until the metric system was adopted in the 1790s, there was no common system of measurements in the world. In Europe the measuring system of the ancient Romans, some 2,000 years old, was still in use in the 1700s. But because standardization was not dependable, Roman feet and inches differed somewhat in size from one town to another. In addition to feet and inches, there were many local units such as the Italian cantarello for weight, the German Metze for volume, or the English tod for weighing wool. The French, in fact, had more than 1,000 units of measurement by the late 1700s with approximately 250,000 variations in size from one town to another. To straighten out this confusion, committees of French scientists during the French Revolution of the 1790s created the metric system.

The international Treaty of the Meter of 1875, of which the United States was an original signer, created permanent international committees to continually refine the metric system’s accuracy based on the latest scientific knowledge. The headquarters of these committees are located today in a suburb of Paris.

All metric units were originally derived from the meter, but by 1900 the metric system began to be based on the MKS (meter-kilogram-second) system. Under this system the unit of mass (the weight of an object at sea level on Earth), was redefined as the kilogram, and the unit of time, the second, was added. Later a unit of the electromagnetic system, the ampere, was added to form the MKSA (meter-kilogram-second-ampere) system. Because scientists needed ever-smaller units, the CGS (centimeter-gram-second) system also came into use. The unit of volume, the liter, was originally defined as 1 cubic decimeter (dm3), but in 1901 it was redefined as the volume occupied by a kilogram of water at 4°C and 760 mm of mercury; in 1964 the original definition (dm3) was restored.

In 1960 major revisions to the metric system resulted in a “new” metric system known as SI after the initial letters of its French name Système International d’Unités. The revisions were adopted at a General Conference of Weights and Measures held by countries using the metric system and resulted in the creation of the International System of Units.

In the United States several attempts were made to bring the metric system into general use. In 1821 Secretary of State John Quincy Adams, in a report to Congress, advocated the adoption of the metric system. In 1866 Congress legalized the use of the metric system, and the system was increasingly adopted, notably in medicine and science, as well as in certain sports, such as track and field. In 1893 the Office of Weights and Measures (now the National Institute of Standards and Technology) of the United States adopted the metric system in legally defining the yard and the pound.

In 1965 the United Kingdom became the first of the English-speaking countries to begin an organized effort to abandon the older units of measurement. Canada, Australia, New Zealand, and South Africa quickly followed and adopted the changeover more rapidly than the United Kingdom.

In 1971, after an extensive study, the U.S. secretary of commerce recommended that the United States convert to metric units under a ten-year voluntary plan. In 1975 President Gerald R. Ford signed the Metric Conversion Act. It defines the metric system as being the International System of Units as interpreted in the United States by the secretary of commerce. The act called for voluntary adoption of the metric system. In 1988 a provision in new federal legislation called for all federal agencies to use the metric system in business transactions starting in 1992, but this was never implemented. Lack of public interest and support has prevented the metric system from being adopted in the United States.

Gauging Tools are special devices used for making accurate measurements. Gauging tools include calipers, depth gauges, taper and thickness gauges, dial and surface gauges, spirit levels and plumb bobs, and straightedges and squares.

CALIPERS AND DEPTH GAUGES

Traditional measurement tools are not applicable in measuring the dimensions of some items, such as the diameters of cylinders and the diameters and depths of holes. Calipers and depth gauges are used instead. In a simple caliper, two movable legs are adjusted to meet the surfaces whose separation is to be measured. The adjusted leg tips are then placed against a standardized length scale to determine the correct measurement. Many calipers have multiple functions: A caliper part called the jaws measures the outside dimensions of an object, the nibs determines the size of the inside diameter of a hole or slot, and the extension bar measures the depth of a hole or shoulder. Calipers are available in either English or metric units. For greater accuracy in making measurements, direct-reading calipers of both the vernier and micrometer types are used.

A vernier caliper has a set of graduated length scales on a main beam. After the jaws, nibs, or extension bar on the caliper have been adjusted to the distance being measured, the user reads the sliding vernier scales to determine the measurement. Reading a vernier scale is tricky and takes practice; many vernier calipers have dials or digital readouts instead.

A micrometer is similar to a caliper but measures a smaller range of lengths, generally measuring distances to within 2.54 micrometers (0.0001 in). The principle of a micrometer is based on the turning accuracy of a fine screw thread. To use a micrometer, the object to be measured is placed in the opening of the micrometer frame. Another part, called the thimble, is rotated until the object is held in place. Readings are taken on the thimble and barrel scales to determine the correct measurement. Digital micrometers are also available.

TAPER AND THICKNESS GAUGES

To measure very small distances—such as the depth of a screw hole or the thickness of a few sheets of paper—taper and thickness gauges are often used. The taper gauge is a tapered metal rod with a measurement scale marked on it. It is slipped into the gap to be measured. The depth of the opening may be determined by reading the number on the taper gauge at the point where it just enters the gap.

A manual thickness gauge is used on a “go” and “no go” basis. The gauge consists of graduated leaves (pieces of varying thickness), which progress in size so that each is 0.025 mm (0.001 in) larger than the last. Different leaves are tried successively in the gap being measured until one is found that will just slip into the gap; the next-largest of the leaves will not fit into the gap. One example of a manual thickness gauge is a spark plug gapper, which is used to measure the small opening or gap between the ground electrode and the spark plug body. Ultrasonic, X-ray, and laser technologies have been used to develop electronic thickness gauges for measuring film, paint, and plated coatings.

DIAL AND SURFACE GAUGES

In woodworking and milling machines, it is often important to know a rotating shaft’s degree of eccentricity (deviation from a circular shape or pattern). Dial and surface gauges are used to make these measurements. The dial gauge is supported with a plunger that rests on the surface of the shaft to be tested. As the shaft rotates, the plunger, pressed against the shaft with a spring, rises or falls as the shaft wobbles. The motion of the plunger is multiplied by a lever system in the gauge and rotates a hand past a fixed dial, indicating the amount of variation. A surface gauge electrically amplifies the movement of a stylus over the surface being tested to give a measurement of its eccentricity.

PLUMB BOBS AND SPIRIT LEVELS 

In building construction and machinery setup, it is customary to set the main axes or planes of the working surfaces parallel or perpendicular to the direction of the force of gravity. The devices ordinarily used to determine these vertical and horizontal positions are the plumb bob and the spirit level.

A plumb bob consists of a heavy weight suspended on a string. By suspending the plumb bob near the supposedly vertical part of a structure, such as a wall or fence post, the amount of deviation from true vertical can be seen relative to the string. The accuracy of this method depends on the symmetry of the weight with respect to its point of attachment to the string.

A spirit level consists of a straightedge along which a glass tube is mounted. The tube is filled with alcohol and contains a single bubble of air or other gas. When the spirit level is placed on a flat surface, the air bubble rises to the top. If the surface is perfectly horizontal, the air bubble will be exactly in the center of the tube. If the surface, such as a picture hanging on a wall, is not horizontal, it may be adjusted until the bubble is centered. By placing the spirit level with its axis perpendicular to the straightedge, the straightedge may also be used in checking vertical position.

STRAIGHTEDGES AND SQUARES

Straightedges and squares measure dimensions and check angles. They are used in such tasks as marking and making a straight cut across a board. Straightedges are basically heavy-duty rules, usually made of metal, while squares consist of two arms that are at right angles, or 90°, to each other. Miter squares have 45° angles. A combination square is shaped so that it can check both inside and outside 90° and 45° angles; it usually includes a small bubble level for quickly checking level and plumb positions as well. Bevels or bevel protractors are used to measure other angles; in these devices, the angle of the square is adjustable.

International System of Units

International System of Units (French Le Système International d'Unités), name adopted by the Eleventh General Conference on Weights and Measures, held in Paris in 1960, for a universal, unified, self-consistent system of measurement units based on the MKS (meter-kilogram-second) system. The international system is commonly referred to throughout the world as SI, after the initials of Système International. The Metric Conversion Act of 1975 commits the United States to the increasing use of, and voluntary conversion to, the metric system of measurement, further defining metric system as the International System of Units as interpreted or modified for the United States by the secretary of commerce.

At the 1960 conference, standards were defined for six base units and for two supplementary units; a seventh base unit, the mole, was added in 1971.

LENGTH

The meter and the kilogram had their origin in the metric system. By international agreement, the standard meter had been defined as the distance between two fine lines on a bar of platinum-iridium alloy. The 1960 conference redefined the meter as 1,650,763.73 wavelengths of the reddish-orange light emitted by the isotope krypton-86. The meter was again redefined in 1983 as the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second.

MASS

When the metric system was created, the kilogram was defined as the mass of 1 cubic decimeter of pure water at the temperature of its maximum density (4.0° C/39.2° F). A solid cylinder of platinum was carefully made to match this quantity of water under the specified conditions. Later it was discovered that a quantity of water as pure or as stable as required could not be provided. Therefore the primary standard of mass became the platinum cylinder, which was replaced in 1889 by a platinum-iridium cylinder of similar mass. Today this cylinder still serves as the international kilogram, and the kilogram in SI is defined as a quantity of mass of the international prototype of the kilogram.

TIME

For centuries, time has been universally measured in terms of the rotation of the earth. The second, the basic unit of time, was defined as 1/86,400 of a mean solar day (see Day) or one complete rotation of the earth on its axis. Scientists discovered, however, that the rotation of the earth was not constant enough to serve as the basis of the time standard. As a result, the second was redefined in 1967 in terms of the resonant frequency of the cesium atom—that is, the frequency at which this atom absorbs energy, or 9,192,631,770 hertz (cycles per second).

TEMPERATURE

The temperature scale adopted by the 1960 conference was based on a fixed temperature point, the triple point of water, at which the solid, liquid, and gas are in equilibrium. The temperature of 273.16 K was assigned to this point. The freezing point of water was designated as 273.15 K, equaling exactly 0° on the Celsius temperature scale. The Celsius scale, which is identical to the centigrade scale, is named for the 18th-century Swedish astronomer Anders Celsius, who first proposed the use of a scale in which the interval between the freezing and boiling points of water is divided into 100 degrees. By international agreement, the term Celsius has officially replaced centigrade.

OTHER UNITS

In SI, the ampere was defined as the constant current that, flowing in two parallel conductors one meter apart in a vacuum, will produce a force between the conductors of 2 × 10-7 newtons per meter of length.

In 1971 the mole was defined as the amount of substance of a system that contains as many elementary entities as there are atoms in 0.012 kilogram of carbon-12.

The international unit of light intensity, the candela, was originally defined as 1/60 of the light radiated from a square centimeter of a blackbody, a perfect radiator that absorbs no light, held at the temperature of freezing platinum. It is now more precisely defined as the intensity of a light source, in a given direction, with a frequency of 540 x 1012 hertz and a radiant intensity of 1/683 watts per steradian in that direction.

The radian is the plane angle between two radii of a circle that cut off on the circumference an arc equal in length to the radius.

The steradian is defined as the solid angle that, having its vertex in the center of a sphere, cuts off an area of the surface of the sphere equal to that of a square with sides of length equal to the radius of the sphere.

The SI units for all other quantities are derived from the seven base units and the two supplementary units. EF

One feature of SI is that it is a coherent system—that is, derived units are expressed as products and ratios of the base, supplementary, and other derived units without numerical factors. This results in some units being too large for ordinary use and others too small. To compensate, the prefixes developed for the metric system have been borrowed and expanded. These prefixes, are used with all three types of units: base, supplementary, and derived. Examples are millimeter (mm), kilometer/hour (km/h), megawatt (MW), and picofarad (pF). Because double prefixes are not used, and because the base unit kilogram already contains a prefix, prefixes are not used with kilogram, although they are used with gram. The prefixes hecto,deka,deci, and centi are used only rarely, and then usually with meter to express areas and volumes. Because of established usage, the centimeter is retained for body measurements and clothing.

Certain units that are not part of SI are used so widely that it is impractical to abandon them.

In cases where their usage is already well established, certain other units are allowed for a limited time, subject to future review. They are the nautical mile, knot, angstrom, standard atmosphere, hectare, and bar.

Carat

Carat, term expressing the ratio of precious metal to base metal in an alloy; also a unit of weight for precious stones. In the first sense, a carat (usually spelled karat) indicates 1/24 part by weight of a precious metal, such as gold, in an alloy. Thus, 18-karat gold is 18/24 or 3/4 gold, and 24-karat gold is pure gold. As a unit of weight for precious stones, the international metric carat, now used by most countries, was standardized by the U.S. government in 1913 at 200 mg, or 0.2 g. This standard carat is divided decimally; 0.01 carat is usually called a point.

Weights and Measures Units – SOME DEFINITIONS

Unit	Definition

acoustic ohm	cgs unit of acoustic impedance (the ratio of sound pressure on a surface to sound flux through the surface)
Acre	traditional English land measure; 1 acre = 4,480 sq yd (4,047 sq m or 0.4047 ha)
acre-foot	unit sometimes used to measure large volumes of water such as reservoirs; 1 acre-foot = 1,233.5 cu m/43,560 cu ft
astronomical unit	unit (symbol AU) equal to the mean distance of the earth from the sun: 149,597,870 km/92,955,808 mi
Atmosphere	unit of pressure (abbreviation atm); 1 standard atmosphere = 101,325 Pa
Barn	unit of area, especially the cross-sectional area of an atomic nucleus; 1 barn = 10-28 sq m
Barrel	unit of liquid capacity; the volume of a barrel depends on the liquid being measured and the country and state laws. In the United States, 1 barrel of oil = 42 gal (159 l/34.97 imperial gal), but for federal taxing of fermented liquor (such as beer), 1 barrel = 31 gal (117.35 l/25.81 imperial gal). Many states fix a 36-gallon barrel for cistern measurement and federal law uses a 40-gallon barrel to measure "proof spirits." 1 barrel of beer in the UK = 163.66 l (43.23 U.S. gal/36 imperial gal)
base box	imperial unit of area used in metal plating; 1 base box = 20.232 sq m/31,360 sq in
Baud	unit of electrical signaling speed equal to 1 pulse per second
Brewster	unit (symbol B) for measuring reaction of optical materials to stress
British thermal unit	imperial unit of heat (symbol Btu); 1 Btu = approximately 1,055 J
Bushel	measure of dry and (in the UK) liquid volume. 1 bushel (struck measure) = 8 dry U.S. gallons (64 dry U.S. pt/35.239 l/2,150.42 cu in). 1 heaped U.S. bushel = 1.278 bushels, struck measure (81.78 dry pt/45.027 l/2,747.715 cu in), often referred to as 1¼ bushels, struck measure. In the UK, 1 bushel = 8 imperial gallons (64 imperial pt); 1 UK bushel = 1.03 U.S. bushels
Cable	unit of length used on ships, taken as 1/10 of a nautical mile (185.2 m/607.6 ft)
Calorie	cgs unit of heat, now replaced by the joule; 1 calorie = 4.1868 J
Carat	unit for measuring mass of precious stones; 1 carat = 0.2 g/0.00705 oz
Carat	unit of purity in gold; pure gold is 24-carat
Carcel	obsolete unit of luminous intensity
Cental	name for the short hundredweight; 1 cental = 45.36 kg/100 lb
Chaldron	obsolete unit measuring capacity; 1 chaldron = 1.309 cu m/46.237 cu ft
Clausius	in engineering, a unit of entropy; defined as the ratio of energy to temperature above absolute zero
cleanliness unit	unit for measuring air pollution; equal to the number of particles greater than 0.5 µm in diameter per cu ft of air
Clo	unit of thermal insulation of clothing; standard clothes have insulation of about 1 clo, the warmest have about 4 clo per 2.5 cm/1 in of thickness
Clusec	unit for measuring the power of a vacuum pump
Condensation number	in physics, the ratio of the number of molecules condensing on a surface to the number of molecules touching that surface
Cord	unit for measuring the volume of wood cut for fuel; 1 cord = 3.62 cu m/128 cu ft, or a stack 2.4 m/8 ft long, 1.2 m/4 ft wide and 1.2 m/4 ft high
Crith	unit of mass for weighing gases; 1 crith = the mass of 1 liter of hydrogen gas at standard temperature and pressure
Cubit	earliest known unit of length; 1 cubit = approximately 45.7 cm/18 in, the length of the human forearm from the tip of the middle finger to the elbow
Curie	former unit of radioactivity (symbol Ci); 1 curie = 3.7 × 1010 becquerels
Dalton	international atomic mass unit, equivalent to 1/12 of the mass of a neutral carbon-12 atom
Darcy	cgs unit (symbol D) of permeability, used mainly in geology to describe the permeability of rock
Darwin	unit of measurement of evolutionary rate of change
Decontamination factor	unit measuring the effectiveness of radiological decontamination; the ratio of original contamination to the radiation remaining
Demal	unit measuring concentration; 1 demal = 1 gram-equivalent of solute in 1 cu dm of solvent
Denier	unit used to measure the fineness of yarns; 9,000 m of 15 denier nylon weighs 15 g/0.5 oz
Diopter	optical unit measuring the power of a lens; the reciprocal of the focal length in meters
Dram	unit of apothecaries' measure; 1 dram = 60 grains/3.888 g
Dyne	cgs unit of force; 105 dynes = 1 N
einstein unit	unit for measuring photoenergy in atomic physics
eotvos unit	unit (symbol E) for measuring small changes in the intensity of the earth's gravity with horizontal distance
Erg	cgs unit of work; equal to the work done by a force of 1 dyne moving through 1 cm
Erlang	unit for measuring telephone traffic intensity; for example, 90 minutes of carried traffic measured over 60 minutes = 1.5 erlangs ("carried traffic" refers to the total duration of completed calls made within a specified period)
Fathom	unit of depth measurement in mining and seafaring; 1 fathom = 1.83 m/6 ft
finsen unit	unit (symbol FU) for measuring intensity of ultraviolet light
fluid ounce	measure of capacity; equivalent in the United States to : of a pint (1/20 of a pint in the UK and Canada)
Foot	imperial unit of length (symbol ft), equivalent to 0.3048 m
foot-candle	unit of illuminance, replaced by the lux; 1 foot-candle = 10.76391 lux
foot-pound	imperial unit of energy (symbol ft-lb); 1 ft-lb = 1.356 joule
Frigorie	unit (symbol fg) used in refrigeration engineering to measure heat energy, equal to a rate of heat extraction of 1 kilocalorie per hour
Furlong	unit of measurement, originating in Anglo-Saxon England, equivalent to 201.168 m/220 yd
Galileo	unit (symbol Gal) of acceleration; 1 galileo = 10-2 m s-2
Gallon	imperial liquid or dry measure subdivided into 4 quarts or 8 pints; 1 U.S. gal = 3.785 l; 1 imperial gal = 4.546 l
Gauss	cgs unit (symbol) of magnetic flux density, replaced by the tesla; 1 gauss = 1 × 10-4 tesla
Gill	imperial unit of volume for liquid measure; equal to 1/4 of a pint (in the United States, 4 fl oz/0.118 l; in the UK, 5 fl oz/0.142 l)
Grain	smallest unit of mass in the three English systems of measurement (avoirdupois, troy, apothecaries' weights) used in the United States and UK; 1 grain = 0.0648 g
Hand	unit used in measuring the height of a horse from front hoof to shoulder (withers); 1 hand = 10.2 cm/4 in
hardness number	unit measuring hardness of materials. There are many different hardness scales: Brinell , Rockwell , and Vickers scales measure the degree of indentation or impression of materials; Mohs ' scale measures resistance to scratching against a standard set of minerals
Hartree	atomic unit of energy, equivalent to atomic unit of charge divided by atomic unit of length; 1 hartree = 4.850 × 10-18 J
haze factor	unit of visibility in mist or fog; the ratio of brightness of mist compared with that of the object
Hehner number	unit measuring concentration of fatty acids in oils; a Hehner number of 1 = 1 kg of fatty acid in 100 kg of oil or fat
Hide	unit of measurement used in the 12th century to measure land; 1 hide = 60–120 acres/25–50 ha
Horsepower	imperial unit (abbreviation hp) of power; 1 horsepower = 746 W
Hundredweight	imperial unit (abbreviation cwt) of mass; 1 cwt = 45.36 kg/100 lb in the United States and 50.80 kg/112 lb in the UK
Inch	imperial unit (abbreviation in) of linear measure, 1/12 of a ft; 1 in = 2.54 cm
Inferno	unit used in astrophysics for describing the temperature inside a star; 1 inferno = 1 billion K (degrees Kelvin )
iodine number	unit measuring the percentage of iodine absorbed in a substance, expressed as grams of iodine absorbed by 100 grams of material
Jansky	unit used in radio astronomy to measure radio emissions or flux densities from space; 1 jansky = 10-26 Wm-2 Hz-1. Flux density is the energy in a beam of radiation which passes through an area normal to the beam in a single unit of time. A jansky is a measurement of the energy received from a cosmic radio source per unit area of detector in a single time unit
Kayser	unit used in spectroscopy to measure wave number (number of waves in a unit length); a wavelength of 1.0 cm has a wave number of 1 kayser
Knot	unit used in navigation to measure a ship's speed; 1 knot = 1 nautical mile per hour, or about 1.15 miles per hour
League	obsolete imperial unit of length; 1 league = 3 nautical mi/5.56 km or 3 statute mi/4.83 km
light-year	unit used in astronomy to measure distance; the distance traveled by light in one year, approximately 9.46 × 1012 km/5.88 × 1012 mi
Mache	obsolete unit of radioactive concentration; 1 mache = 3.7 × 10-7 curies of radioactive material per cu m of a medium
Maxwell	cgs unit (symbol Mx) of magnetic flux, the strength of a magnetic field in an area multiplied by the area. 1 maxwell = 10-8 weber
Megaton	measurement of the explosive power of a nuclear weapon; 1 megaton = 1 million tons of trinitrotoluene (TNT)
Mil	(a) one-thousandth of a liter; contraction of the word milliliter; (b) imperial measure of length, equal to one-thousandth of an inch; also known as the thou
Mile	imperial unit of linear measure; 1 statute mile = 1.60934 km/5,280 ft, and 1 international nautical mile = 1.852 km/6,076 ft
millimeter of mercury	unit of pressure (symbol mmHg) used in medicine for measuring blood pressure
Morgan	arbitrary unit used in genetics; 1 morgan is the distance along the chromosome in a gene that gives a recombination frequency of 1%
nautical mile	unit of distance used in navigation, equal to the average length of 1 minute of arc on a great circle of the earth; 1 international nautical mile =1.852 km/6,076 ft
Neper	unit used in telecommunications; gives the attenuation of amplitudes of currents or powers as the natural logarithm of the ratio of the voltage between two points or the current between two points
Oersted	cgs unit (symbol Oe) of magnetic field strength, now replaced by amperes per meter (1 Oe = 79.58 amp per m)
Ounce	unit of mass, : of a pound avoirdupois, equal to 437.5 grains/28.35 g; or 14.6 pound troy, equal to 480 grains/31.10 g
Parsec	unit (symbol pc) used in astronomy for distances to stars and galaxies; 1 pc = 3.262 light-years, 2.063 × 105 astronomical units, or 3.086 × 1013 km
Peck	obsolete unit of dry measure, equal to 8 imperial quarts or 1 quarter bushel (8.1 l in the United States or 9.1 l in the UK)
Pennyweight	imperial unit of mass; 1 pennyweight = 24 grains = 1.555 × 10-3 kg
Perch	obsolete imperial unit of length; 1 perch = 51/2 yards = 5.029 m, also called the rod or pole
Pint	imperial unit of liquid or dry measure; in the United States, 1 liquid pint = 16 fl oz/0.473 l, while 1 dry pint = 0.551 l; in the UK, 1 pt =20 fl oz, 1/2 quart, 1/8 gal, or 0.568 l
Point	metric unit of mass used in relation to gemstones; 1 point = 0.01 metric carat = 2 × 10-3 g
Poise	cgs unit of dynamic viscosity; 1 poise = 1 dyne-second per sq cm
Pound	imperial unit (abbreviation lb) of mass; the avoirdupois pound or imperial standard pound = 0.45 kg/7,000 grains, while the pound troy (used for weighing precious metals) = 0.37 kg/5,760 grains
Poundal	imperial unit (abbreviation pdl) of force; 1 poundal = 0.1383 newton
Quart	imperial liquid or dry measure; in the United States, 1 liquid quart = 0.946 l, while 1 dry quart = 1.101 l; in the UK, 1 quart =2 pt/1.137 l
Rad	unit of absorbed radiation dose, replaced in the SI system by the gray; 1 rad = 0.01 joule of radiation absorbed by 1 kg of matter
relative biological effectiveness	relative damage caused to living tissue by different types of radiation
Rood	imperial unit of area; 1 rood =1/4 acre = 1,011.7 sq m
Roentgen	unit (symbol R) of radiation exposure, used for X- and gamma rays
Rydberg	atomic unit of energy; 1 rydberg = 2.425 × 10-18 J
Sabin	unit of sound absorption, used in acoustical engineering; 1 sabin = absorption of 1 sq ft (0.093 sq m) of a perfectly absorbing surface
Scruple	imperial unit of apothecaries' measure; 1 scruple = 20 grains = 1.3 × 10-3 kg
Shackle	unit of length used at sea for measuring cable or chain; 1 shackle = 15 fathoms (90 ft/27 m)
Slug	obsolete imperial unit of mass; 1 slug = 14.59 kg/32.17 lb
Snellen	unit expressing the visual power of the eye
Sone	unit of subjective loudness
standard volume	in physics, the volume occupied by 1 kilogram molecule (molecular mass in kilograms) of any gas at standard temperature and pressure; approximately 22.414 cu m
Stokes	cgs unit (symbol St) of kinematic viscosity; 1 stokes = 10-4 m2 s-1
Stone	imperial unit (abbreviation st) of mass; 1 stone = 6.35 kg/14 lb
strontium unit	measures concentration of strontium-90 in an organic medium relative to the concentration of calcium
Tex	metric unit of line density; 1 tex is the line density of a thread with a mass of 1 gram and a length of 1 kilometer
Tog	measure of thermal insulation of a fabric, garment, or quilt; the tog value is equivalent to 10 times the temperature difference (in °C) between the two faces of the article, when the flow of heat across it is equal to 1 W per sq m
Ton	1 unit of mass; the long ton ( UK ) = 1,016 kg/2,240 lb; 1 short ton (United States) = 907 kg/2,000 lb; 1 metric ton = 1000 kg/2205 lb
Yard	imperial unit (symbol yd) of length, equivalent to 0.9144 m/3 ft

Now to go into further details, would be inappropriate at this point, so my dear, I’ll keep it at this.

But there is something that I want you to remember here that what is great about this in relation to our country? INDIA?

Well, the entire decimal system and the figure 0 “zero” has been given to the world by India and that is what makes our country great. We all try to follow the world over, follow the lifestyle of Americans, British, French, but what we don’t realize that with all the problems and set backs in our own country, we have the greatest assets located with us, which we don’t use at all.

The Germans for example mastered Sanskrit language during World War II in order to translate the Indian Vedas and scriptures, to find out details of various hidden formulae of our past. I won’t be surprised that tomorrow someone turns up to tell us that that was the origin of the Nuclear Science!!!

Sanskrit language is supossed to be the most computer friendly language in the world. But how many people in India really know it properly. Not many. Think what all we can accomplish if we know it, if we understand it.

Same ways, Mathematics. As I told you 0 and the decimal system was given to the world by our great mathematicians of the past, and today we learn a lot about mathematics, but we forget that while we learn the calculus and differentiation, the vedic mathematics which is not understood or practiced much today is highly advanced and easier once understood.

Our education system in India, may be the best, but it makes us followers... slaves of what others want us to know. None of our books teach us these great things, neither these are in our syllabus. This is what makes us slaves… slaves of what the western countries want us to know, while they use our data base to go into scientific advancement. Remember without experimenting with life and practices, we will never be able to give up this slave mentality. Because we are dependant on what others have been telling us. We really don’t have an independent view or opinion of our own.

Remember you are all tomorrow’s children and it was not possible for me to understand this at an early stage because no one made me understand. But you can change that in your generation. Learn the good and bad, follow your heart and don’t follow what you see others are doing. Discipline in life is very important and without it you’ll tend to go wrong more often then not. One way to realize what is right and what is wrong is by knowing what is easier to do. The easy will more often be wrong. Not always but the easier the road is the wrong it turns out to be.

Follow your hearts, do what you think is right, where you don’t hurt those you love, and do what will make your parents proud of you. If there is anything you think will not make your parents proud of you, don’t do it. Do not cheat others and don’t lie until it is very important, but only to the extent of not doing wrong to anyone. Lying is not wrong till the time it is done for happiness of everyone around you, but does not do any wrong to anyone.

Remember all that I’ve written above is not really something that I remember but because I can research and find it from various sources. It is not necessary in the world to know everything, but it is important to find your way to that knowledge.