Once more we see comments that are based upon such spurious resources as Wiki which in this subject are virtually worthless.
Go to my page on Scribd http://www.scribd.com/harry_sivertsen
which was referenced in my early post and read the papers there then move to the books on the same site...all is free. Over 20 years of hard won knowledge for nothing!
As a number here are making comment regarding the metric system I introduce the history of the change to metric, in most cases, only a simple calculation to move from one version to the next.
A Product of the Revolution - The Development of the Metric System
The story of the metric system begins over three hundred years ago. For many years in Renaissance Europe there had been discussions about the need for a coherent system of measurement in order to better scientific communication and enhance trade.
The above need reminds us of a similar situation regarding standardisation problems in the transfer of scientific data in the 1970’s. These were solved by scientists at CERN, the European Nuclear Research Institute in Geneva, who invented html, the so-called mark up language of internet web pages, which became the standard format for scientific document transfer during the 1980’s.
Standardisation problems abounded in mediaeval Europe; 17th century France in particular had standards of linear and volume measure that varied from town to town across the country, which made trade difficult, and obviously, the subject of much potential dispute. It was in 1670 that Gabriel Mouton, a vicar at St. Paul’s Church in Lyon, first suggested a unit associated with Earth measurement, namely 1/40,000,000 of the Earth’s longitudinal circumference. Mouton's proposal contained three of the major characteristics of the future metric system: decimalization, rational prefixes (i.e. a standard set of unit multiples and sub-multiples), and a unit of length related to the Earth's dimensions. Mouton's proposal was debated for some 120 years, but it was not to be until the fall of the Bastille and the creation of the National Assembly that it became a political possibility in France. In April of 1790, one of the foremost members of the National Assembly, Talleyrand, introduced the subject of standardisation of measurement to the Assembly, launching a debate that resulted in a directive to the French Academy of Sciences to prepare a report.
After several months' study of available data [such as Bouger’s, see footnote] the Academy came up with a series of recommendations. The main one of interest to us here was that the Academy recommended that length of longitude passing through Paris be determined from the North Pole to the Equator, and that 1/10,000,000 of this distance would become a new standard length, termed the metre. This unit would then form the basis of a new decimal linear measurement system which would be extended to include a new unit of weight, derived from the weight of a cubic metre of water. In addition, the Academy also proposed a list of prefixes for decimal multiples and submultiples.
The revolutionary National Assembly endorsed the above milestone of a report and directed that the necessary measurements be taken. This was formalized on June 19, 1791, when a committee of 12 mathematicians, geodesists, and physicists met with the King, Louis XVI, who gave the Royal Assent to the submitted proposals. Incidentally, the next day, the King and Marie Antoinette attempted to escape from France, but were caught at Varennes. [They would have made it if the coach had not been delayed for a long time in order to load a large trunk containing the Queen’s toilet set.] Louis XI and Marie Antoinette were forcibly returned to Paris, where the King was imprisoned and a year later he played his last part in this story. Here, from his cell, he issued the proclamation that directed two engineers, Jean Delambre and Pierre Méchain, to perform the surveying operations necessary to determine the length of the new standard unit.
Newton’s assertion that Earth was an ellipsoid was further confirmed by a number of French surveying expeditions in the early 18th century. In 1735, Pierre Bouger travelled to Peru with Charles-Marie de La Condmine to ascertain the length of the meridian (or line of longitude) between various latitudes in the region, which is approximately south of the equator by the same distance as Paris is to the north. The following year in an expedition to Lapland, similar measurements were made by Pierre-Louise Moreau de Maupertuis. Utilising triangulation, these surveyors and their teams confirmed that the Earth was, as Newton had predicted, flattened at its extremities.
Delambre and Méchain now set to work to measure the distance on the meridian from Barcelona, Spain, to Dunkirk in northern France, a task so arduous that it was not completed for six years. While Delambre and Méchain were struggling in the field, administrative details were being worked out in Paris and in 1793 a provisional metre was constructed from geodetic data already available. In 1795, a draft law defining the metric standards of length, mass, and capacity was produced, along with the prefixes for multiples and submultiples. The standard metre, as determined by Delambre and Méchain, was formally presented to the Assembly in 1799 and was adopted on June 22nd of that year.
The motto of the metric system that introduces this chapter is ironic here, as one of the key themes of Measurements of the Gods is that whilst there were indeed a variety of units of measurement in use, these were linked to a canon of numerical units of measurement based on geodetic dimensions that had existed around the world not merely for a few hundred years, but for millenia.
For those who understood, these units were interrelated and posed no problems. Among those who were aware of the values were the designers of palaces, cathedrals and monastic buildings during the period when metrication or ‘standardisation’ was introduced in France. We must conclude from this that although a man of the church, Gabriel Mouton was unaware of the geodetic nature of the measurements already in existence and inherent in his own place of worship.
Basic elements of the Metric System
The new metric system comprised a number of elements - the standard metre as derived by Delambre and Méchain, the gram, litre and are. The gram, the basic unit of mass, was made equal to the mass of a cubic centimetre of pure water at the temperature of its maximum density [which was defined as 4 degrees Centigrade or 39.2 degrees Fahrenheit]. A platinum cylinder known as the Kilogram of the Archives was declared the standard for 1,000 grams whilst the litre was defined as the volume equivalent to the volume of a cube, each side of which had a length of 1 decimetre, or 10 centimetres. The are was defined as the measure of area equal to a square 10 metres on a side. In practice the multiple, hectare or 100 ares, [approximately 2.47 imperial acres] became the principal unit of land area measurement. In addition, names for multiples and submultiples of all units had a uniform style, based on Greek prefixes.
The year 1823 saw the introduction of legislation in France to enforce the use of the new measurement units, an enforcement that was still necessary as late as 1837.
This reminds us of the United Kingdom today, where there is still a reluctance to use the ‘new’ metric measures by many older people who have been brought up using the old Imperial system, in fact a recent move by the government has allowed the old values to remain in use provided traders also display the metric equivalents. Indeed, some building materials such as plywood can still be obtained in imperial sizes…even in 2009!
However, during the period under discussion, the mid 18th to the early 19th centuries, in Britain a similar move toward standardisation was taking place. The Select Committee of the House of Commons was set up to report on the Original Standards of Weights and Measures in ‘this kingdom’. On May 26th1758 and April 11th 1759, the Select Committee submitted reports upon the units then in use and recommended that the Ale Gallon of 282 cubic inches should be that which replaces all other interpretations of the gallon. They also suggested that the Troy pound should be the basis of all weight measurement.
Later, after a period of inactivity regarding any standardisation two eminent scientists were consulted by the committee, one Dr. W. Hyde Wollaston, Secretary to the Royal Society, and the other being a Professor Playfair of Edinburgh. Their recommendations as outlined here were finally passed by the Committee in 1816 and were in use at that time.
One of the recommendations that emerged was for a yard that contained 36 inches with the inch derived from an accurately balanced pendulum, sited in the middle of London and that vibrated at 60 times per minute. The length of this pendulum had been calculated at 39.13047 inches of which 36 made the yard.
This basically defined the linear measure as the yard was seen to be 3.3702 inches shorter than the newly developed French metre at 32 degrees Fahrenheit and 3.3826 inches shorter at 55 degrees Fahrenheit. Correlation was therefore seen to two invariable stands, the measure relating to Earth’s meridian circumference of which the metre was 1/40,000,000 and the pendulum in London.
The Select Committee recommended that the pint should be comprised of 34.56 cubic inches with the quart at 69.12 cubic inches and gallon at 276.48 cubic inches. [Note: 69.12 miles = one degree of anciently accepted Earth circumference and 34.56 inches = the Egyptian [as named by Michell of which more later] step measure. Also compare numerical counts to the values associated with Indian weights in Chapter 15.] Here it should be noted that all the liquid measures were conducted at 561/2 degrees Fahrenheit. A cubic foot of pure water or 1728 cubic inches, at 561/2 degrees Fahrenheit weighed exactly 1000 ounces Avoirdupois. This was taken as the standard from which all else in the realm of weight / liquid measure evolved as 1728 cubic inches means a cube of exactly 12 inches per side. The volume of water of a single pound Avoirdupois therefore was seen to be 27. 648 cubic inches.
Just a few years later, in 1824, the Weights and Measures Act of that year decreed somewhat different values. The linear measures remained the same but due to the fact that the conditions for evaluating liquid were altered, the volume correspondingly changed and the gallon was now quoted at 277.274 cubic inches making the pint 34.69525 cubic inches against the earlier recommendation of 34.56. In 1824 the temperature for evaluation was set at 62 degrees Fahrenheit with the barometer at 30 inches, which of course meant an expansion of the unit weight utilised to ascertain the displacement volume of water in the pint, gallon etc. If we examine what could have been observed in the case of a weight to ascertain a pint volume for example at the earlier assessment taken at 561/2 degrees Fahrenheit, the pint, as noted, had a displacement value of 34.56 cubic inches which from the unit numbers involved [34.56, 1728, 6912 and 12], will be seen to be 100 percent compatible with the system that dates to millennia before this event. At the new interpretation taken at the higher 62 degrees, the weight utilised to ascertain the displacement volume had expanded to the volume of 34.69525 cubic inches, an increase of 0.0042436 of an inch or 1/9.277 of a millimetre per side. As the earlier British measures were compatible the with ancient units as seen above, it becomes apparent that the Imperial measures were intimately related to these vastly older units.
In Chapter 16 we return to this subject of weights in much more detail but here we shall look once more to the French initial interpretation of the metre and to the implications arising. The Select Committee noted the reported difference between the yards and the metre at two different temperatures, 32 degrees Fahrenheit and 55 degrees Fahrenheit which naturally gave two different readings. We shall take the lower value which was read at freezing point, 32 degrees Fahrenheit. This difference was 3.3702 inches, making the metre 36 plus 3.3702 or 39.3702 inches in length. This meant that the French calculation for the Earth’s meridian circumference was 40000000 x 3.28085 feet or 24854.92424 miles. The ancient’s version for a globular Earth was 24883.2 miles, a difference of some 28.2 miles.
The SI System
At this point it is useful to explore a reason for the eventual pervasiveness of the metric system – namely it’s expansion into a much wider technical and scientific field. The creation of the decimal metric system at the time of the French Revolution can be seen as the first of a number of steps in the development of the present International System of Units, commonly known as the SI system.
In 1832, Gauss strongly promoted the application of the new metric system (together with the second defined in astronomy) as a coherent system of units for the physical sciences. In the 1860s, under the active leadership of Maxwell and Thomson, the British Association for the Advancement of Science [BAAS] formulated the requirement for a coherent system of units consisting of base units, and derived units. Consequently, in 1874 the BAAS introduced the CGS system, a three-dimensional method based on the units centimetre, gram and second, using prefixes ranging from micro to mega, to express decimal submultiples and multiples. The development of physics as an experimental science was largely based on this system.
The sizes of the coherent CGS units used in the fields of electricity and magnetism proved to be inconvenient, so in the 1880s, the BAAS and the International Electrical Congress approved a mutually coherent set of practical units. Amongst them were the well known nowadays, Ohm for electrical resistance, Volt for electromotive force, and the Ampere for electric current. In 1889, the CGS system was amended so that the base units were changed to the meter, kilogram and second. [Note: We now use the French spelling for the meter – metre] Later, in 1946, the CGS system was expanded to include the Ampere as a unit of electrical current. Further expansion to include the Kelvin [temperature] and candela [light] was made in 1960, where the modern name of the SI system was born. Finally, in 1971, the current version of the SI system was completed, by adding the mole as base unit for amount of substance, bringing the total number of base units to seven.
Alexander Ross Clarke and the advent of British Geodetic Surveying
While France was adopting the metric system, Britain still maintained the Imperial system of measurement, which was standard throughout the British Empire. Indeed, while the French were producing their surveys, in the late 18th century, Britain was also engaged in a similar exercise: the first complete trigonometrical survey of the British Isles. This was to eventually result in what we recognise in modern times as the Ordnance Survey, the initial work being completed in 1852.
Alexander Ross Clarke [1828 – 1914], a pioneer in modern surveying, was closely involved in this work, and he published the results of the first geodetic survey of Great Britain in 1861. His calculations of the size and shape of the Earth [known as the Clarke ellipsoid] were the first to approximate accepted modern values with respect to both polar flattening and equatorial radius. The figures derived from his second set of calculations  became a standard reference for geodesy in the United States for most of the twentieth century, even though he had never set foot on North American soil.
3.4 The Last Days: The End of the Imperial Measurement System
The quotation heading this chapter is a little tongue in cheek, in that while it may have been utilised in the context of the new metric system, the system that it was displacing was actually as ancient as human civilisation itself. This system, the Imperial measurement system, had already been proven to be capable of being described as ‘For all peoples, for all time’. What we knew as the British Imperial system is but a part of a completely integrated numerical system, which was so beautiful in its connectivity, it was almost like poetry in numbers. Algernon Berriman’s fear, noted in his work Historical Metrology in 1953, that a heritage of ‘great antiquity’ was to disappear from daily life began to be borne out during the course of the 1960’s, as the process called metrication began in Britain. Feet, inches and other associated units began to be replaced by a unit new to Britain - the metre - and its various offspring such as the kilometre. In a similar way, the British, or rather imperial, units of weight and volume were to be supplanted by ‘metric’ units. This attack on Britain’s heritage was incurred, supposedly, via an Act of Parliament in 1963. The word ‘supposedly’ is used here because there are many who would argue that there was no such Act, and the concept of metrication, whether for good or otherwise, had been hoisted onto the British public by stealth. Whatsoever, by stealth or otherwise, in 1963, a national changeover began. According to Chambers Dictionary, in 1963 the yard was defined as 0.9144 of a metre, making the metre 3.280839895feet or 39.37007874 ins. It is this value that is used throughout Measurements of the Gods and is the now internationally accepted interpretation.
The metrication process in Britain has been slowed by a great emotional attachment by the British to the old Imperial units. For example 30 years after metrication, it was still possible to purchase items in Imperial sizes such as sheets of Malaysian plywood, and there are many examples in the world of engineering where the metric system has not taken hold. However, one had to purchase ones building materials, whether metric or imperial in a metricated currency in Britain, as the British monetary system ‘went decimal’ in 1971, triggering off an inflationary spiral, which has resulted in the pound being worth in 2003 perhaps 10 per cent of its value in 1971. However, four feet, apart from being the equivalent of 1.2192 metres, is still four feet, as indeed, a second is still a second…even when measured by an atomic clock…
Some measurement units in life have altered dramatically while others have remained constant. In this context then, how much longer we will be able to order a very old measure, a pint of beer, [albeit not quite the same measure as that of the 18th century] is a matter of conjecture. But if metrication is to be complete, even this time honoured tradition will be relegated to the realms of history, and the pint and half pint glasses will be consigned to history museums, along with imperial barrels and kegs.
How had the Imperial System come into being? The accepted story has a typically British mediaeval feel about it, and here we examine a part of the history. 14th century statutes recognise a yard of three feet, the ‘Iron Yard of the King’ [reputedly his girth] with each foot having twelve inches. A barleycorn, according to these statutes, was equal to a third of an inch hence there were 36 barleycorns to a British foot and 108 to a British yard. The standards for these measurement units were kept at Winchester and were known, appropriately, as the Winchester standards, which incidentally were both reaffirmed by King Henry VII and Queen Elizabeth I.
What seemingly enhances the apparent approximations of the measurement units used is that, in the 16th century it was customary to line up sixteen men heel to toe as they left church and evaluate the overall length of their feet. This value was then the local rood or rod length. By the early part of the 17th century, statute had standardised the acre, furlong and rood or rod [also known as the pole or perch] accurately [in British units] to 4840 square yards, 660 feet and 16.5 feet respectively. The acre was also defined as 40 rods in length, by four rods in width, giving 160 square rods or 43,560 square feet.
During the 17th century, Edmund Gunter developed the measuring device known as the surveyor's chain based on the acre width of 4 rods [792 British imperial inches, or 66 British feet, or 22 yards]. [Note the ‘rod, pole or perch’ was a length of 16.5 feet.] This chain is a familiar distance today, even in a metricated world – it is the length of a cricket pitch. It should also be noted here that this supplies a link to the ancient past as this distance is the height from ground level of the head of the Great Sphinx at Giza in Egypt. In fact, the ancient Egyptians among others in the distant past were very fond of this value and it is seen in monuments in the Middle and New Kingdoms as well as the Old. This may be because if this length is converted to inches, the result is a count of 792. The value 792 in various formats occurs very widely in the ancient and not so ancient worlds.
As the anciently accepted diameter of Earth was 7,920 miles of the variety known in modern times as British, it would appear that there is a definitive link as is confirmed in later chapters. Thus it is easy to envisage that the length of a surveyor’s chain, which itself is used for geodetic or Earth measurement, is a deliberate representation of numerically symbolic values with which the 16.5 feet of the ‘rod, pole or perch’ were directly related via a different factor.
The above standardisation of lengths actually began, as indicated, long before the 17th century, and was part of Edward I's statute of 1305. British units, according to the Encyclopaedia Britannica, were initially defined in terms of Northern feet which were also known as German feet. The furlong, 1/8th of a mile and still known to lovers of horse racing everywhere, was 625 German feet although the appendage ‘German’ is unlikely to have been used as this was a standard measurement. The mile did not change length but with a change of foot value there now were 660 of the new shorter feet to the furlong with 5280 to the mile. The conversion factor from Northern feet to Standard English feet, or what later were known as simply British feet, is obtained by dividing the 660 British feet by the original 625 Northern feet which results in 1.056, i.e. 1.056 British feet is equivalent to the length of the German foot. It has been noted that the British mile is the odd man out in the ancient measurement system as it is the only mile with a count of feet at variance to the original 5,000. However, at this point another issue regarding the history of the mile is raised:
It has frequently been stated that the mile was standardized to 5,000 feet in Roman times. It will become obvious, however, that this is an erroneous idea and that the mile, as a 5,000 feet unit of geodetic measurement, stems back to what is generally termed pre-history.
This is extracted from Chapter 3 of the book Measurements of the Gods where full referencing is applied.