Category Archives: Centimeters or Millimeters

An Open Letter Response To: “Supporting American Choices on Measurement”

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Dr. Patrick Gallagher — Director of NIST

Dear Dr. Gallagher:

This open letter is in response to your email/post entitled Supporting American Choices on Measurement which you composed in response to a We The People petition, which calls for making the metric system (that is, SI) the exclusive measurement system of the United States. In brief, what you offer is not a substantive response to a reasonable petition for action on an increasingly urgent issue, but only condescension and airy rationalization for perpetuating our current bureaucratic stasis.

First, the metric system, is a system. The random collection of measures used in the US is not a system. They are neither equivalent nor comparable. I am disturbed that the head of NIST can speak of the metric system, and our potpourri of units, as even remotely comparable in either intellectual stature or technical merit. But far more important, the very thesis of Supporting American Choices on Measurement is false on the face of it, as there is no actual opportunity for a metric option in this nation. In my postings on metric, I have written about The Invisible Metric Embargo in the US, which does not allow me to purchase metric tools—despite my desires as a consumer. One simply cannot readily purchase metric-only, mm-only, tape measures, and other tools in the US. I’ve had to obtain mine from Australia to use in my Engineering Practice. They are the same tools that are used in metric building construction, which the US government has quietly abandoned after the 1990s. Metric construction saves 10-15% when compared with our non-system. The Australians have been reaping these metric rewards for over thirty years. I have detailed this in Building a Metric Shed. Over the counter medicines are allowed by your “freedom of choice” to offer only teaspoons and tablespoons. Feral Units Endanger Our Health details the teaspoon/tablespoon, gram/grain misdosage problem, which has been acknowledged by the medical community since at least 1902. Mandatory dosage cups in milliliters have been eschewed by industry for years, to the detriment of public health and justified, probably for the most part, by the need for “freedom of choice.”

I may have the choice to set my GPS to meters and kilometers, but I don’t have the choice to press a button within my car and change the road signs to meters and kilometers. The choice of only miles and feet (in vulgar fractions no less) on US road signs was decided by filibuster, in 1978, by Senator Charles Grassley of Iowa. The details of how this mandatory requirement for miles and feet on US road signs came about, may be found in A Tale of Two Iowans. What channel do I watch to see a metric only, or even a metric any weather broadcast in the US? Metric measures in weather broadcasts also ended in the late 1970s. I would like to see snow and rain totals in millimeters, but I do not have that choice.

The public teachers of the 1970s began to teach metric, but quickly realized that the US was to be the only country (other than Liberia and Myanmar) which had a government that would not institute a true metric conversion. The teachers were left without a measurement ecosystem outside of their classroom to which they could teach, and so metric instruction was “all dressed up with nowhere to go.” Metric instruction has become perfunctory.

If we actually had the completely open, voluntary system about which you sing peons of praise, then why is there any restriction on manufacturers to include labeling other than metric at this moment? And why do you have to work “to make it possible” for metric only labeling? If it is not allowed right now, then metric only is obviously not a voluntary choice for industry. The non-system of the US is mandatory.  It does not support your thesis that everyone has a choice.

That measurement units need “context” for meaning, and are chosen depending upon the given circumstances is nonsensical. Why not just create a new measurement unit for each circumstance—like medieval cultures did? The non-system we use in the US, measures feet in barleycorns (three barleycorns in an inch you know), to determine shoe size, instead of millimeters. What possible context makes the measurement of human feet require barleycorns as a unit? Perhaps a foot should be measured in feet? That seems like a logical context. My essay Brannock and Barleycorns might help you with context when considering this question.

You cite examples of multiple units which are in use and describe the same quantity as something wondrous which we should lionize. This is not an advantage, it is a problem called unit proliferation. In the US, people who work with tools have to needlessly purchase both metric and inch tools. This doubles the infrastructure cost for working Americans. It is also a large drag on our economy. Weights and measures is The Invisible Infrastructure of a nation. Ours is in complete decay, yet you celebrate this fact.

There is no “seamless transition” between metric and our non-system. Dual units only encourage unnecessary opportunities for mistakes. Metric minimizes them. The DART and Mars Climate Orbiter mission failures which occurred because of the “choice” to use multiple measurement units, are examples which should not be swept under the rug with charming prose, like “seamless transition.”

Incidentally, your statement that the metric system is universal in science and industry is also demonstrably false. I grant you that it should be, but I know from personal experience that the US aerospace industry is currently hamstrung by something called the mil. A mil is one thousandth of an inch. Now, you might suppose that this would be an ideal time for a metric conversion in US aerospace: after all, with the long-overdue retirement of the Space Shuttle, the United States has no astronaut-capable space vehicle. But the contract for Orion, the manned vehicle intended to replace the Shuttle, was awarded to Lockheed Martin, at least in part, on the understanding that all engineering would be submitted in thousandths of an inch.

Dr. Gallagher, your response has shown that, as I predicted, this petition would be a feckless exercise in futility, and of no lobbying value. The public is viewed not as We The People, but They The Powerless. Your response demonstrates an apparent technical ignorance about the metric system. It makes you appear to have not even a basic understanding of how the measurement system that powers engineering and science around the world is used, and it’s massive advantages for society as a whole.  I would think It should be obvious to a Director of NIST, that a measurement system and a spoken language are two completely different intellectual constructs. Especially a Director with a background in physics and philosophy. My essay Orwell and The Metric System might be instructive if you are unclear on this point.

To compare the measurement situation we face in the US to bilingual education is mendacious. Your whitewash of the history of how the current non-system of measurements were finally defined in terms of metric standards, hides the fact there was no other technical choice. There was no alternative. Without using the metric standards supplied from our signing of the Treaty of the Meter, science and industry in this nation could have ground to a halt. T.C. Mendehall had no choice but to announce that metric standards would be used to define our farrago of units. This is because of government inaction on mandating metrication, and the fact that no alternative measurement standards existed for our non-system. The Constitution tasks Congress with fixing the weights and measures of the US, which they have neglected with vigor from the founding of the republic.

As Director of NIST, I cannot comprehend how you could assert there is no weights and measurements problem in the US whatsoever, and everything is just hunky-dory. This is clearly not the case. I have written forty-six essays over the last year or so detailing how our lack of exclusive metrication, costs us money, endangers our health and decreases our industrial competitiveness. The late Pat Naughtin left a classic Google video lecture, and a mountain of information on how damaging it is for the US not to have metric. How can you have apparently not investigated any of it?—and included it in your response? The information is freely available. I can only ask with exasperation why are you not promoting the metric system?—why are you not engaged in the carrying out the task for which the public has employed you?–to promote standards. The metric system is the standard of ninety-five percent of the worlds population. Why are you not promoting this standard with the sense of urgency that it deserves?

Your choice to issue Supporting American Choices on Measurement late on the Friday before Memorial Day weekend is as transparently cynical as is your response. The timing is calculated to minimize or eliminate any press coverage with three days of distraction. In doing this you are blatantly, and apparently willfully, ignoring the 25,000 49,914 American citizens who signed the petition for the US to adopt the metric system. Because of your callous and dismissive treatment of an earnest request made by these citizens for the implementation of the metric system, this only leads to a justified belief that our public servants have no interest in serving the public, or the public interest.

Respectfully,

The Metric Maven
US Citizen and Professional Engineer

P.S. To my (at this point, fairly) long time readers, I would like to state that my next regularly scheduled blog on 2013-05-30, was written, and scheduled, long before Dr. Gallagher issued his response to the metric petition. When you read my upcoming blog, you will see the same manner of argument as Dr Gallagher’s has been offered for almost a century. Dr. Gallagher only parrots the antique prose in a contemporary fashion.

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is not of direct importance to metric education. It is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.

Building a Metric Shed

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By The Metric Maven

One evening over the phone, my friend Lapin told me that he spent the weekend with another Engineer, Mr. Landi, building a shed. Mr. Landi suggested they build it using metric so it would be more accurate. Apparently this exercise in construction went down hill immediately.  “We made all kinds of mistakes cutting lengths.” Lapin said exasperated. I then asked a question which took Lapin by surprise:

“Did you build it using centimeters or millimeters?”

“It makes a difference?” Lapin inquired with incredulity.

“Yes, you’re prone to make numerous errors when you use centimeters. Millimeters eliminate a major source of those errors, by eliminating the decimal point.”

I explained that in Australia, nothing but millimeters are used for their building construction. The numbers are all simple integers, and no addition or subtraction with decimal points are needed. The least numerate of the workers can use a calculator to add and subtract integers with ease and accuracy. It’s saved Australia about 10-15% on the cost of construction since their metric conversion in the 1970s, when compared with imperial.

It was hard to fault Lapin or Mr. Landi for not using millimeters. In the US, obtaining a decent metric tape measure, or other construction tools in millimeters, is almost impossible, because of The Invisible Metric Embargo.

The formal recommendations for metric construction in the United States is in the Metric Design Guide (PBS-PQ260) September 1995. Here is what it has to say about the use of centimeters in construction:

Centimeters (cm)

Centimeters are typically not used in U.S. specifications. This is consistent with the
recommendations of AIA and the American Society of Testing Materials (ASTM).
Centimeters are not used in major codes.

Use of centimeters leads to extensive usage of decimal points and confusion to new readers. Whole millimeters are being used for specification measurements, unless extreme precision is being indicated. A credit card is about 1 mm thick.

Here is the Guide’s statement about millimeters:

Millimeters (mm)

SI specifications have used mm for almost all measurements, even large ones. Use of mm is consistent with dimensions in major codes, such as the National Building Code (Building Officials and Code Administrators International, Inc.) and the National Electric Code (National Fire Protection Association).

Use of mm leads to integers for all building dimensions and nearly all building product
dimensions, so use of the decimal point is almost completely eliminated. Even if some large dimensions seem to have many digits there still will usually be fewer pencil or CAD strokes than conventional English Dimensioning

A Canadian building construction guide has nice illustrations of the difference—which are absent in the US guide. Unfortunately, Canada’s building trades have not converted to metric, which is why I generally discuss the Australians instead. I have not been able to locate Australian building guides. This is why you will find none in this blog.

The Canadian guide shows how to read a metric tape measure. This tape measure has two units on it meters and millimeters. You can compare it with an Australian tape measure I own below. It remains all millimeters, but only counts off the 100 mm between without the largest digits.

Canadian Illustration of How To Read A Metric Tape Measure (click to enlarge)
Australian Metric Tape Measure (click to enlarge)

Next the Canadian guide shows a typical wall dimensioned with imperial units.

Example Wall With Imperial Dimensions (click to enlarge)

It never strikes Americans as excessive to use two units to describe every dimension. Feet and inches are found everywhere, along with fractions.

The same wall is then presented as it would be dimensioned and drawn using millimeters. The numbers are all simple integers.

Example Wall With Metric Dimensions (click to enlarge)

No Feet and inches, no fractions, no decimal points, and just one unit used for all sizes. The dimensions are easy for a novice or experienced builder to read clearly. Experience in Australia shows that workers will attempt to cut to the exact millimeter when given tools with that capability. We would have more accurately constructed buildings, which are more weather-tight, simply by switching to metric.

Pat Naughtin relates that the head of AVJennings construction in Australia had two identical houses constructed, one in imperial and one in metric. It took two large trucks to haul away the scrap from the imperial work site. The metric house work site had only about a wheelbarrow full. When reformed in a rational up-to-date manner, metric can provide easy dimension checks.  Pat relates that Australian bricks are 90 mm thick, and are specified to have 10 mm of “mud” between them. This means that if you have ten rows of bricks laid down, they should measure exactly one meter. Imperial units simply do not accommodate this manner of easy check.

One owner of an Australian construction company has a blog entry with a title which is succinct concerning our American building practices: Why not going Metric makes America a laughing stock. He concludes his blog entry thus:

One of the last hold outs in a the push toward metric is the American building industry. The lure of inches for lumber and lengths in feet is seemingly irresistible. (it is even curious that the Americans call that timber a 2X4, where in Australia it was a 4X2) To avoid the confusion…… the Australian building industry declared.

The metric units for linear measurement in building and construction will be the metre (m) and the millimetre (mm), ….. This will apply to all sectors of the industry, and the centimetre (cm) shall not be used.’

We banished the centimetre as some defacto inch measurement and have never looked back.

It speaks volumes about the US that they believe in some unalienable right to an outdated, and uniquely strange system of measures in this current millennium.

Related essay:

The Metric Dream House

If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page and contribute. Also purchase his books about the metric system:

The first book is titled: Our Crumbling Invisible Infrastructure. It is a succinct set of essays  that explain why the absence of the metric system in the US is detrimental to our personal heath and our economy. These essays are separately available for free on my website,  but the book has them all in one place in print. The book may be purchased from Amazon here.


The second book is titled The Dimensions of the Cosmos. It takes the metric prefixes from yotta to Yocto and uses each metric prefix to describe a metric world. The book has a considerable number of color images to compliment the prose. It has been receiving good reviews. I think would be a great reference for US science teachers. It has a considerable number of scientific factoids and anecdotes that I believe would be of considerable educational use. It is available from Amazon here.


The third book is not of direct importance to metric education. It is called Death By A Thousand Cuts, A Secret History of the Metric System in The United States. This monograph explains how we have been unable to legally deal with weights and measures in the United States from George Washington, to our current day. This book is also available on Amazon here.