Institutional Myths About The Metric System

By The Metric Maven

Bulldog Edition

We were reminded on December 23, 2016 by Elizabeth Gentry, coordinator of NIST’s Metric Program, that on that same date in 1975 (1975-12-23) Gerald Ford signed The Metric Conversion Act. In an essay titled Busting Myths about the Metric System, Ms Gentry indicates that the CIA map of countries that use the metric system is “simply untrue!” and further states:

While it’s true that metric use is mandatory in some countries and voluntary in others, all countries have recognized and adopted the SI, including the United States.

Indeed, the US recognized the metric system in the 19th century, and allowed its use, but did not mandate it. The use of the word adopted by Ms. Gentry is curious, to most people this word means that a person has taken an idea for their own use, usually abandoning the old method.

The only change in our relationship with the metric system, that I’m aware of, was when John Kasson made the metric system legal for people in the US in the 19th century. From that moment on, our association with the metric system, from a legal point of view, remains unchanged. This was pointed out by a member of the American Bar Association in the 1975 metric hearings.

Ms. Gentry goes on to state:

Dr. Russ Rowlett at the University of North Carolina at Chapel Hill emphasizes on his website that becoming metric is not a one-time event but a process that happens over time. Every international economy is positioned somewhere along a continuum moving toward increased SI use. There are still countries that are amending their national laws to adopt mandatory metric policy and others pursuing voluntary metrication.”

Dr. Rowlett is a retired professor of Mathematics.

The statement that no country is 100% metric, is the sort of argument that anti-metric crusader Fredrick Halsey trotted out in the early twentieth century, as proof that no country has adopted the metric system. This assertion is a version of the continuum fallacy. Suppose you are broke, and I give you a penny, are you rich?, how about a second penny? at what point can I give you one more penny, and you are now “rich?” It is also cast in the form of at what point do you remove a hair from a persons head that he is now “bald?” If one adopts this view, then no country on Earth is metric, and Halsey is right. One can only offer a defined partition that has no firm basis. Should the drinking age be 18? 19? 21?, when does a person become an adult?

A graphic called “The Metric Continuum” is offered for the US, which appears to be an attempt to normalize the fact that the US is not even close to a metric country. The measures in the US are nothing but a farrago of medieval units, and sorting them into a Metric Continuum Fallacy changes that not one yoctometer.

While no one-time event will make a country 100% metric, but it might get it to more than 90% metric very quickly. I recommend Dr. Rowlett read Metrication In Australia. Without that one-time event (if I can use event to mean a decade) Australia might be in the situation that Britain finds itself, stuck about halfway or so–but it’s hard to say how metric Britain actually is. It is difficult to know how metric the US, UK or Australia are as there has never been a professional audit and study to find out. The figure often trotted out, that the US is 50% metric, appears to have its basis in proctology.

Ms Gentry also invokes the idea of mandatory and voluntary “metrication” in her statement. This really obscures the situation in the US. We’ve had voluntary metrication
since 1866. John Shafroth realized that we needed mandatory metric in 1905 or so, but it was soundly defeated. In 1921 it was argued that voluntary metric was the way to go, and again in 1975, people like Clayborn Pell deluded themselves into the idea that voluntary metrication was fast bringing the the metric system to the US.

But wait! Wasn’t the metrication of Australia voluntary! What was voluntary in Australia, was how each industry would become metric, not if industry was going to become metric. There were fines and encouragement to become metric. There were deadlines called M-days for different sectors of their economy to become fully metric. US politicians willfully allowed the public to believe that Australia’s metrication was spontaneous, and quickly appeared without any government intervention or guidance. Alan Harper who directed Australian metrication wrote to Congress and told them so:

It is, of course, not possible to mount a wholly voluntary metric change in the sense that every individual has a free choice. Consider the conversion of statutory speed limits and other changes calling for embodiment in legislation. “Voluntary” in this
context has to be taken to mean that the choice of a program and plan for conversion in a sector is made voluntarily by national leaders in that sector but thereafter it is supported by all the pressures that can be marshalled, through procurement, legislation, appropriate amendment of technical standards, adherence to the program by government and large organizations and so on.

Unless your Metric Board can enlist such support for the programs developed voluntarily, the agreement accorded many of these programs may in the event prove too fragile to ensure their implementation and aspects of your metric operation which provide their own incentives will get out of kilter with those needing some additional stimulus for their accomplishment.

Harper would later tell the Metric Board in person that he could not have made Australia metric with the US laws as they exist.

Voluntary metrication is a myth, and an institutional one embraced within the US government. Another myth is “we tried in the 1970s and it just didn’t work.” Another version of this myth is that the US government tried to impose the horrible metric system on its citizens who then revolted and cowered their representatives into repealing the legislation, showing a true example of democracy in action! That is a common myth and completely false.

Later we are told by Ms. Gentry that:

It’s been legal to use the metric system since 1866, and metric became the preferred system of weights and measures for U.S. trade and commerce in 1988.

Well, let’s talk about the legislation of 1988. First the Reagan administration and Congress wants everyone to know that metric is Voluntary, Voluntary, Voluntary:

6) The Federal Government has a responsibility to develop procedures and techniques to assist industry, especially small business, as it voluntarily converts to the metric system of measurement.

and not in the Australian sense of the word voluntary when dealing with metrication. One can see from the design of everyday objects that the US, in practice, “prefers Ye Olde English.”

Non-Preferred US Packaging (click to enlarge)

There is some fear that metric countries around the world might suddenly adopt our measures, and put us at a competitive disadvantage if we fully adopt metric. The legislation addresses this imaginary concern:

(b) POLICY. Section 3 of the Metric Conversion Act of 1975 is amended to read as

SEC. 3. It is therefore the declared policy of the United States

(1) to designate the metric system of measurement as the preferred system of weights and measures for United States trade and commerce;

(2) to require that each Federal agency, by a date certain and to the extent economically feasible by the end of the fiscal year 1992, use the metric system of measurement in its procurement, grants, and other business-related activities, Except to the extent that such use is impractical or is likely to cause significant inefficiencies or loss of markets to United States firms, such as when foreign competitors are producing competing products in non-metric units;

(3) to seek out ways to increase understanding of the metric system of measurement through educational information and guidance and in Government Publications; and

(4) to permit the continued use of traditional systems of weights and measures in
nonbusiness activities

By nonbusiness, it is fairly clear that the business defined above is government business. Private industry is completely off-the-hook. So what does preferred mean? Most people would see it as a primary choice with a second acceptable choice in case the first is not available. One might prefer beef to chicken, but chicken is fine.

The very word prefer does not enforce metric in the US, it is just more of a statement of almost equivalent substitution. Two options that are almost on an equal par in the general vernacular. Often the design of our everyday objects reveals that metric is not preferred. Ms Gentry goes on:

It’s impossible to avoid using the metric system in the United States. …..  I envision U.S. metric practice like a huge iceberg. Above the water’s surface, U.S. customary units appear to still be in full effect. In actuality, below the water’s surface we find that all measurements are dependent on the SI, linked through an unbroken chain of traceable measurements.

It is also impossible to avoid Roman numerals in the United States, but I’m not sure what that would exactly mean. Envisioning “metric practice” as an iceberg, which seems to imply that 90% of US usage is metric and 10% is what we see? This is not what I’ve experienced in my visits to US engineering and production facilities that still exist. People can’t even purchase millimeter only tape measures, or rulers, or drill bits, at any US hardware store.

I realize that Ms. Gentry’s position is a difficult one. She operates under a law that has no teeth, and essentially sees metric and Ye Olde English as more-or-less equivalent, and states that one is “preferred” like buffalo over beef in a sandwich. When the public signed a We The People petition requesting that the US Government make the metric system mandatory in the US, her former boss was tasked with the required reply, and told us all how great it is to live in a measurement country which is “bilingual.” This metaphorical assertion is an absurd non-sequitur. I had much to say about his anemic response here.

I realize that given the situation in the US, one would do their best to keep a positive tone, but one of the first things a person must do to remedy a problem is to
recognize its existence. The US has a weights and measurements problem, it is non-metric to the extreme, which makes it complex and prone to error, which in turn wastes resources. There is no everyday usage in the US that compels a person to use metric. Not at the post office, not at the DMV, not on our roadways, not when using our airlines, not when watching a weather forecast, not when buying paper, not when buying a television, not when making purchases at a grocery store, not when cooking with a recipe, not when buying natural gas or electricity (no Kilowatt-hours are not metric), not when at a cafe, not when purchasing gasoline, or a car—even though all the parts of a car are of metric sizes, not when purchasing furniture,  and not when buying parts for home improvement. The metric exceptions in our nation are minor, and examples difficult to come by. Prescription medicine may be metric, but patent medicines are notoriously Ye Olde English. I would wager a majority of Americans could not estimate how much a gram is, despite milligrams and microgram dosages existing on medicines. Metrication in the US is an almost complete failure. Presenting myths that it is otherwise, is, in my view, counterproductive and serves to propagate the current inaction.


The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.


It’s Déjà Vu All Over Again (1916-2016)

leisure-suit-larryBy The Metric Maven

Bulldog Edition

The title of this essay is of course a famous quotation attributed to Yogi Berra. It also expresses my experience when I decided to see what was said in early 20th century issues of the American Machinist magazine from about a century ago. This interest was precipitated when I noticed a large number of hits from a subreddit about propaganda posters connecting to The Metric Maven website.

Most people think that US metrication (or the lack of it) first took place in the 1970s, and, along with mint green leisure suits, is relegated solely to “The Decade That Taste Left Behind.” The early 20th century saw a number of attempts by people like John Shafroth to pass mandatory metric legislation (something not even contemplated in the 1970s). It was very strange to realize that the same arguments and issues that are discussed by metric advocates in 2016 were also present in 1916.

The 1916 issues of American Machinist are interesting in that one would have expected their pages to be complete polemics against the metric system as the editor, Ethan Viall, is completely anti-metric. To my surprise, some of the best arguments for adopting metric are found in its pages, but written as letters to the editor.


The pages of this weekly devote more and more column-millimeters to anti-metric prose as the 1921 metric hearings approach. One common “argument” found within its pages is that metric people are just a bunch of longhairs. For instance, in 1920 (Vol. 53, No. 2 pg 70) we read:

Theory (Calculate) vs. Use

In discussing the pros and cons of the metric question, it has been aptly said that the pros are represented by by the professors and the cons by the constructors.

Also (Vol. 45, No. 18 pg 780) editor Ethan Viall asserts:

[… As to the men who want the metric system so badly, they seem to be scientists and pseudo-scientists who have use for units of measurement to put down the sizes of things that exist, but not for the dimensions of things to be made — Editor]


In the last few years I have come in contact with scientists and professors, among them chemists and so-called chemical engineers. These men generally used dimensions and measures in the abstract only in their calculations and in the investigations of the many problems presented to them. Many of them have no conception of the mechanical limitations encountered in the development of their ideas into commercial propositions, and they therefore become strong advocates of the metric system, which for their work has some advantages. (Vol 45, No. 19 pg 828)

Of course the work of scientists is not “real work.” Editor, Ethan Viall, in response to some of the letters to the editor, finally resorts to a technical Darwinism argument against metric:

[The metric system is not established to the exclusion of all others in any country that we know. In Germany the inch  (Zoll) is still largely used, and in France the inch (pouce) is also extensively used. “The Metric Fallacy,” will give Mr. Greenleaf a lot of information on the different standards used in so-called metric countries.—Editor]

Ethan Viall asks: if metric is so great, why isn’t imperial/Olde English extinct in the wild? This of course assumes that humans are rational beings, an assumption that appears inconsistent with its author’s own views, and one’s general experience with life. Finally, Frederick Halsey’s sad polemic The Metric Fallacy is offered up as a pound of prose, that, independent of content, vanquishes a Yottagram of reason. For Halsey, questionnaires are an excellent substitute for investigation, and a single use of non-metric in a metric country means that metric Tinkerbell has died.

Some of the letters to the editor are fanciful, such as a long-winded argument for a base 8 measurement system. Others introduce cogent and recognizable contemporary arguments. What is most interesting, is the pro writings all seem to understand the importance of millimeters. Centimeters are generally introduced by detractors. One millimeter example is a letter to the editor from Adolf Langsner of Chicago Illinois:


In all our industries of light and medium nature no one, from the tool maker down to the machinist apprentice, can get along without a number of tables that the metric man would ignore entirely. Here is a little conversation which actually took place and which shows characteristically where the English system is of advantage to a modern industry:

Scene—in a medium-sized shop. Jim (who came from the other end of the floor): “Say, Fred, what size drill must I take for a 19/64-in. reamed hole?” Fred, a little surprised: “Why, ain’t ye have yer drill gauge!”

After pausing a while Fred continued: “Oh, I see; 19/64 in. is larger than a quarter, and No. 1 drill is the largest in the gauge. Well, how much is 19/64 in.?”

Jim took his “mike” out of the apron. Looking at it he gave the equivalent, 0.2968. “Oh, well,” he added, “let’s make it 0.297.”

Fred was well pleased with the change in decimals, because he instantly exclaimed, “That’s better.” He crossed out the first figure and wrote the second down. “Let me see,” Fred continued a while, “I think a drill in the neighborhood of about 0.288 to 0.20 in. will be right.”

“Ain’t ye smart?” shouted Jim again, “I know all that myself. What I want to know is the number or letter of such a drill.”

“I ain’t have not table; we have to ask Lang,” replied Fred.

Both repeated the story to me. While I took out my “American Machinist’s Handbook” and looked up index and page for letter-size drills, Jim, Fred and Gus, who “butted in” to see what the argument was, had a little conference. The question came up whether a 9/32-in. drill was not big enough. Jim assured them that 1/64 was too much to ream and that he had to make fifty pieces in a hurry. In the meantime I found that letter “L” drill is 0.290 in.

Here is a case where four men spent about fifteen minutes. The “Old Man” did not know that Jim had to get special information for the hurry job. Neither did the efficiency man know that an hour’s time was wasted and that such time is lost daily. Otherwise he might have introduced some new, efficient system—namely, the metric system.

If the man in the metric shop has to ream a 7.5-mm. hole (about 19/64 in.), he knows instantly that 7.4 and 7.3 drills are the nearest smaller sizes he can use. Suppose the same man has to make some special screws, say 5-mm. thread and 10.5 head. At once he knows that his two diameters have to be the same as given. On the other hand, if the man with the English standard has to make similar screws, say 10-32 with 13/32-in. head, the first thing he has to do is to “look up” what diameter No. 10 is and then get the decimal equivalent of 13/32.

We cannot get away from the fact that, whether calculations are done on the drafting table, in the raw material department or in the shop, there is always a necessity of converting fractions into decimals and vice-versa. These conversions alone have caused many a job to be “junked,” and a “firing” followed, no to mention the confusing mass of data of different wire gauges, sheet-metal gauges and other standards that cause endless trouble and waste of thousands of hours daily. …..

This was indeed deja vu all over again. My essay Without Metric Threads We’re Screwed points out that machinists still find calipers or use a micrometer to determine the decimal equivalents of drill bit sizes. Drill bit sizes come in fractions of an inch or number letter designations, but not in decimal inches. One cannot immediately know what drill size one needs for a 10-32 screw as the designations are uncoordinated and were created in the wonderland of technical Darwinism. I touch on this in my essay A Hole in The Screw Head. If one wants to drill a hole that is the same size as an M7 fastener (7 mm diameter) then one would locate a 7 mm drill bit. Fraction to decimal conversion charts are ubiquitous in shops throughout the US. If we used the metric system, they would be as obsolete as slide rules. Further, metric drill bits are not found in any US hardware stores, as I point out in my essay Yes! We Have No Metric Drill Bits. But who am I to question Metric Philosophers and their powerful philosophy of technical Darwinism that encompasses their imaginary ecosystem of rational human beings?

More often what one discovers is that humans have spent time learning a way to do something and are terrified that this knowledge will become obsolete. Rationality has nothing to do with their choice. I wrote the essay Isaac Asimov–Technophobe to address this issue. This concern was as true in 1916 as it is today. In a letter to the editor, Martin H. Ball of Watervliet, NY has  this to say:

If, instead of worshiping the theoretical, the rabid advocates of the metric system will divert their efforts toward changing the units of that system to dimensions that are thinkable, they will be doing me a good turn. …  the length of the meter [should be] changed to 40 inches. That would divert their attention to something practical.

As I have said before, it has cost me years of hard work to get the technical education that I now have, and to rob me of it is no more right than it is to rob me of any other of my possessions. And to make me think and work in the metric system would be doing just that.” (American Machinist 1916-09-28 pg 561).

It’s deja vu all over again!

One aspect that is lost on all these machinists in 1916 is that a single value for the inch did not exist, which caused confusion and scrap. It was not until 1959 when it was decided that 25.4 mm is an inch, just before Australia, New Zealand, Great Britain, and all the other “Anglo-Saxon” English-speaking countries, with the exception of the US, decided to become metric in the 1970s and make the agreement moot.

One self-described “practical man,” W. Osborne of Oil City, Pennsylvania, had this to say (Vol. 45, No. 13 pg 560) in American Machinist:

A practical man might have realized that the diameter of the earth could not be measured correctly without instruments,. ….

Indeed, instruments are a good idea, but I’m not sure why the diameter of the Earth is brought into a metric discussion when it was the circumference of the Earth that was of interest. The “practical” man goes on to inform us:

Now the meter is a piece of metal that the United States Government says is 39.37 in. long in the United States, but a little bit longer than that according to some textbooks. One of the books states that it is 39.37043 in., another that it is 39.3707904 in., and still another states that it is 39.36996 in.

As I am a citizen of the United States, 39.37 in. it legally is to me, and I’m rather forced to think that our meter is either 39.37 times our inch or else our inch is the meter divided by that number. I am not certain which is which, but I do know that if I am reading in the English system and trying to think in the metric system, my inches must be divided by 39.37 and the answer pointed off at the right place to have them changed to centimeters.

Centimeters are for detractors and millimeters for metric allies in the pages of American Machinist. But the author does not seem to realize that in 1916 “our inch” does not exist other than as defined by the metric system. The inch as a separate independent standard did not exist. The decision to define the US inch using metric standards was made by a practical man, who realized that the imperial yard standard from Great Britain was not stable or workable. He took the practical step of defining the US inch in terms of the only practical standard available, that of a meter. Congress would not act, so this practical man saw that practical instruments required that he define the US yard as 3600/3937 meters.

This practical man was, of course, Thomas Corwin Mendenhall. Thankfully, so as not to injure the sensibilities of the “practical” author of this letter to the editor, Mendenhall was an autodidact. He was also a great promoter of the metric system. The calibration of all the instruments Mr. Osborne would use during his life could be traced back to a metric bar in Mr. Mendenhall’s care. Our inch, is a metric inch. defined from the length of a meter.

Carl F. Jeansen, Ordinance Engineer at the Washington Navy Yard in Washington D.C. related how Sweden converted to metric in five years. After that, a contract in any other system of units was no longer legal, and had no standing in court. Mr. Jeansen was at the Gothenburg Mechanical Works, which employed somewhere around 1000 to 1200 men when the change to metric occurred (American Machinist Vol. 45, No. 26 pg 1136):

The change from inches to millimeters was immediately started. All new drawings were made in the metric system, and when an old drawing was to be used the dimensions in millimeters added. At that time Swedish, English and Prussian inches were used in shop work. It was a relief to throw them out and use millimeters. In this shop the metric system reduced the number of errors in the drafting room and the cost of manufacture.

The change was carried through with practically no expense whatsoever. The taps in the Whitworth system were kept as they had to be used for repair work. Later on metric taps were gradually substituted.

When the American Machinist presented an article comparing the inch-pound non-system and metric in 1920 (“The English and the Metric Measuring System—A Comparison” 1920-11-11 pg 511), the centimeter is crammed in for rhetorical use. But first technical Darwinism must be introduced, after pointing out how great the US and Great Britain are as industrial powers:

This does not imply that the English system of measurements is perfect. Some of its units and sub-divisions have become obsolete by disuse. This is as it should be. It is a matter of evolution and growth stimulated by experience and changed conditions…”

Then the “primary units” of the metric system are introduced:


The accompanying illustrations. Figs. 1 and 2, show some relative comparisons of English and metric units of length. A study of Inch-Foot-Yard and Centimeter-Decimeter-Meter will show at once that the former three dimensions harmonize perfectly for practical use, while in the latter the unit sub-divisions of the meter represent too great a step from the meter itself. In the “inch” and “centimeter” the same defect is apparent, to which is added, the “indivisibility” of the centimeter into 1/2, 1/4, 1/8 and so on as compared with the inch.


Despite the fact that in the very pages of American Machinist, the pro-metric letters to the editor implement millimeters, and a centimeter is not to be found,  their formal comparison article offers up the centimeter as a bad version of an inch (which it is). After subjecting the rest of the metric system to this “analysis” the conclusion is obvious, just before the 1921 metric hearings they offer a Goldilocks conclusion:


Briefly stated the metric system is devoid of the English system’s handiness and convenience; its units are either too large or too small for the every-day requirements of industry. From the English system many sub-divisions have been dropped, having outlived their usefulness; thus proving the English system’s adaptability to the requirements of progress. The metric system, on the other hand, presents a rigid structure incapable of modifications and requiring conditions to adapt themselves to its use.

Fredrick Halsey resumed his metric salvos of ignorance in 1917 within the pages of American Machinist. Again the introduction of centimeters as a pseudo-inch was employed as grist for Halsey’s rhetorical mill:

Fig. 1 shows an English and a metric scale in contact. The lines upon the English scale give the dimensions to which things have always been made in English-speaking countries, and reduced to its lowest terms, the proposition before us is that these sizes shall be abandoned and those shown on the metric scale be substituted for them.


It is difficult to believe that Mr. Halsey is not aware of what he is doing. The pages of American Machinist are filled with millimeters as the “practical” small unit for metric work, yet as I show in my essay The Metric Fallacy?, he appears to have called a centimeter scale a millimeter one to make the metric system seem to be a more confusing version of inches. Here he is more cautious and uses the terms “English and metric scales”  rather than labeling a centimeter scale as a scale of millimeters. This is a curious difference compared to his earlier writing and I suspect it is not by accident.

Halsey’s article is almost embarrassing in its juvenile arguments. I will not burden the reader with examples from it.

Elsewhere, simplicity is sacrificed for the “practical” so that a non-metric world can be maintained. One letter to the editor attacked the idea of pipe sizes in metric. The author used conversions from Ye Olde English to argue the equivalent sizes obtained were odd and unworkable. In a reply, it was pointed out that one could easily change pipe sizes to simple integer millimeter dimensions in terms of fractions (American Machinist 1916-11-23 pg 915):



Under the banner, Letters from Practical Men, a conversion chart for inches to millimeters is offered in December of 1916:


Over and over it is apparent to all those involved and familiar with metric in the pages of the American Machinist, that millimeters are the unit of choice, but Ye Olde English habits die hard and they adversely affect the metric system. J. Pearlman of Walthamstow, England offers to show us how simple metric conversion is:

Let us proceed to convert 50,204,378 mm to kilometers. Starting from the right-hand side tick off each figure–50 km., 2 hm., 0 decam., 4 m, 3 decim., 7 cm., 8 mm. With the other system the process would be, first divide by 12, then by 3, then multiply by 2 and divide by 11, then divide by 40, then by 8.

Wow, as I’ve pointed out in previous essays, even this baroque use of the metric system seems simpler to the contemporaries of 1916 than Imperial/Ye Olde English. Today, the prefix cluster around unity is eschewed and we write this value as 50 204 378 mm. The triads immediately show us this value is 50 204 meters, or essentially 50 Km if it were a value to be placed on a roadway sign.

Again it’s deja vu all over again as I addressed this in my essays Naughtin and 1929 and Familiarity Versus Simplicity.

It is not deja vu all over again for the rest of the world. They have embraced the metric system.

Updated on 2017-01-09

Related Essay:

The Metric Fallacy?


The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.