The Smithsonian and the Metric System

In September, I got a much-needed getaway. During that time, I made a trip to Washington D.C. to visit friends.

While there, I took advantage of my proximity to visit my contact at the National Institute for Standards and Technology (or NIST and the keepers of the metric system in the United States).

Artifacts in the museum at the National Institute of Standards and Technology in D.C.

Artifacts in the museum at the National Institute of Standards and Technology in D.C.

The NIST Museum

I was at NIST three years ago when I was just a few weeks into this project. Needless to say, my experience at its museum was radically different now that I had some context for the things that I saw. (Note: the museum is open only to official visitors. Still, there is a lot of information on the organization’s website.)

I also got a chance to meet with Elizabeth Gentry, my NIST contact there, and our country’s finest Metric Coordinator. While I’ve been keeping her up-to-date on the project, I’d yet to meet her in person.

Convert between systems only when necessary

I’m not sure how or why, but the friend I was staying with had some old U.S.-to-metric conversion slide rules imprinted with the Detroit Teachers Credit Union logo and a copyright of 1973.

A conversion "helper" from the 1970s

A conversion “helper” from the 1970s

One of the complaints that I’ve heard while on this project has been that our last attempt to convert to the metric system back in the mid-1970s spent too much time trying to teach people conversion formulas. Transitioning this way is actually quite complicated because there are so many formulas to memorize because we use so many different units (feet, pounds, ounces, gallons, ounces, etc.). The image to the right only captures part of the problem.

Any future plans to adopt the metric system would benefit from just straight measurement using the metric system, rather than trying to teach very complex and lengthy sets of conversion factors. (Only convert when absolutely necessary, like your grandma’s favorite recipes.)

For example: Do you have a space that needs a table? Just measure using the metric side of the ruler and do the same when shopping. I know I’m oversimplifying but it’s a start.

We were early decimal adopters—our coins

Needless to say, now that I’m involved with the metric system, I see its relevance almost everywhere.

Display depicting the different coins in use in colonial America prior to our independence.

A display depicting the different foreign coins in use in colonial America prior to our independence and establishment of our own mint.

I did end up coming across a coin display at the National Museum of American History (part of the Smithsonian museum complex) called “Legendary Coins & Currency.” It reinforced some of my previous research that one of the reasons that the United States ended up with decimalized currency came from the fact that when we landed on this continent, we were not allowed to mint our own money while still part of England.

Note this quote from the History of Colonial Money that I found on the Federal Reserve Bank of Boston site:

By 1652, the problem resulting from a shortage of coins had become extreme. England had turned a deaf ear to the colonists’ plea for specie [gold and silver coin. ed], and the colonial leaders did not believe that the people should have to continue using the mixture of foreign coins, wampum, bullets, and barter objects any longer. In an effort to provide more good coin to further trade and commerce, the Massachusetts Bay Colony established an illegal mint in Boston in 1652.

That meant that we had a total mishmash of currencies, not only from our home country but with all the other countries with which we were trading. And there were many. It made for a difficult time. Thomas Jefferson was more than well aware of the problem as one source notes:

…one of Jefferson’s most troublesome legal clients finally paid him in a motley mixture of silver and gold — half joes and moidores from Portugal, doubloons and pistoles from Spain, and 308 English half crowns.

As a result, our fabulous founding father:

…had the rational idea to create a decimal-based currency system. Meaning that money should be based on the number ten. The word for one hundred in Latin is cent, so Jefferson suggested that the word for a 1/100th of a dollar be “cent.” The Latin word for “one tenth” is dime; so again, Jefferson suggested that as the name for the 1/10th of a dollar coin. The five-cent coin would become known as the half dime and then later, the nickel.

Thus, he was able to move us as a nation to the decimalized currency we still use in the U.S. today.

Jefferson was one of the earliest Americans to consider a decimalized currency. He gave it, in 1784, its most articulate and persuasive expression in his “Notes on Coinage.” Congress, convinced by these arguments, adopted the new coin units with little dissent.

Unfortunately, he has more problems passing a decimalized system for our lenghts. But that’s another post.

[Please note: I am now starting a book on the subject of metric system adoption in the United States. I will post to this blog on occasion but the bulk of work on this project (when not at my full-time job) will focus on writing the book. If you want to keep up with what I’m doing, the best thing will be to follow my Twitter feed and Facebook page. I’m finding those easier to keep up with. I now hope to post here once a month.)

Stay tuned!



Living La vie Mètrique: An Australian’s Take on Metric System Adoption Part II

It’s forty-one years since the metric conversion process began in Australia, and thirty years ago the Metric Conversion Board lowered their flag, produced their last report and said “Mission Accomplished.”

So what has changed? Just about everything, that’s what!


A metric kitchen

Here’s a photo of what’s in my kitchen cupboard: a kilo of flour, a liter of vinegar, a 100 gram jar of coffee. The water bottle is 600 mL, as that size replaced the Imperial pint. You can also get 1 L and 2 L sizes for milk and other liquids. The plastic container of pasta at the back has a capacity of two liters, and that size is stamped on the base; a lot of storage containers are marked like that.

(Note: All the photos in this article, plus a few extra are available here: at a slightly larger size)

A loaf of bread is usually 680 g, as that replaced the 1½ pound loaf, but you find other sizes. The labels on the supermarket shelves include comparison prices (in $ per kilo or $ per 100 g) to make it easy to compare prices of different-sized packets.

All of the products except the tin at the far right are labelled in metric units only. The only ounces or fluid ounces I ever see are on goods intended for the US or UK markets.

Beer is sold in 750 mL “long necks” or 375 mL “stubbies.” Wine is also in 750mL bottles, or in casks (Americans call it box wine) of two or three liters.

Metric road sign

Metric road sign

Traffic signs are all metric. Speed limits are in kilometers per hour (abbreviated km/h), distances in kilometers and  height clearances in meters. Speed limits are usually 40 or 50 km/h around built-up areas, 60 km/h on arterial roads, 80 or 100 km/h (sometimes 110) on highways.

Walking and cycle tracks have distances marked in kilometres or meters on signposts. In fact, unless the distance is meters the unit is omitted, so if you see a sign saying “City 5.3” you can correctly assume it is kilometers.

Cars have had metric nuts and bolts for years, the same as the US, and we buy gas and oil by the litre. Engine capacity is in litres and power is in kilowatts instead of horsepower.

My gas meter reads in cubic meters and my water meter clicks over a notch every time a liter flows through it. Electricity bills have always been in kilowatt-hours, and on gas bills they convert the cubic meters into the energy consumption in megajoules (MJ) where it used to be in therms. (1 therm = 100 000 BTU)

At the hardware store, what you would call a “2 by 4” and we used to call a “4 by 2” is now sometimes advertized as 100 x 50 mm and sometimes as 90 x 45 mm. Timber is sold by the metre or in lengths which are multiples of 1200 mm to match the standard 1200 x 2400 mm plywood and plasterboard. (2 x 4s are actually a bit smaller than the advertized size, the metric dimension is the finished size.)

Nails and screws are listed with descriptions like “Nails, Bullet Head, Galvanised, 75 x 3.75 mm” and you can buy them in packs of 2 kg or more if you are building something big. Wood screws and self-tapping screws are described by length in millimeters but their thickness is by gauge. Some old measures keep hanging on.

Plumbing fittings, electrical conduits, switches: all their sizes are in millimeters, but I think the British Standard Pipe Thread might outlast civilization itself. I used to install water-saving showerheads and their flow was listed as 9.5 liters per minute.

The standard ceiling height for houses is 2400 mm (7ft 10½ ins) which was dropped from 8ft to accommodate a rational metric size. A standard door is 2040 mm high, about 6ft 8in. The builders do everything in millimeters; there are no centimeters and no misplaced decimal points.

Buying an appliance? Airconditioners, heaters and stoves all do their cooking in degrees Celsius. The capacity of your refrigerator is measured in liters. It’s easy to envision an array of milk cartons that the fridge will hold when making comparisons. The capacity of a washing machine or dryer is in kilograms.

TVs (and computer monitors) are usually measured in centimeters, but you still see a lot of them advertised in inches for the screen size. The dimensions of all products, appliances, furniture, curtains, bedsheets, is always in millimeters or centimeters and their weight is in kilograms.

Paper sizes changed, too. Australia previously used the British sizes with strange names like Octavo and Foolscap, and odd ratios of height to width. Now, ISO 216 sizes are used everywhere. Standard writing paper is A4, 210 x 297 mm; two of them side by side are an A3 poster-sized sheet if you turn it through 90º, and an A4 folded in half is an A5 which is suitable for a pocket notebook.

This makes things easy for enlarging and reducing on a photocopier; you scale the original up by 41% or down to 71% to get to the next size. You see fliers, bills, newsletters, posters, catalogs, brochures; all of them based on the A-series paper size.

Weather forecasts are all metric, as is information in the news. Temperatures are in degrees Celsius, rainfall in millimeters and wave heights in meters at sea, but wind speed is in knots for shipping and km/h on land.

When they were discussing irrigation and river flows on the news a while ago, (a hot topic on a continent that is mostly desert,) we heard about megaliters and gigaliters. That’s a thousand and a million metric tons of water. A serious amount of water.

The language hasn’t changed a lot. People still use terms like footage, mileage and say “going the extra mile,” but in describing metric measurements people will say so many ‘mil’ for millimeters or milliliters, and say ‘kilos’ for kilograms. The next pub might be a few ‘kays’ down the road.

There are still a few minor problems. Clothing sizes for one. For mens’ trousers and shirts it’s just a matter of measuring the neck or waist in centimeters. For womens’ clothing there is a supposedly standard set of sizes, but no two manufacturers are alike. Also, sizes have inflated over the years, as we have become a nation with a larger waistline. (I remember seeing a cartoon of a woman telling her husband “Size twelve? No, much too big. Get me a size ten, and make sure it’s the biggest size ten they’ve got.”)

Shoe sizes are much the same. My feet are the English size 9 but I wonder, 9 what? Why can’t they just measure the length from toe to heel? That’s how they do it for the flip-flops (thongs) you wear on the beach.

You can’t get incandescent light bulbs any more, they are all compact fluorescents, so instead of bulbs being described in watts, which is a measure of the power they consume, the output is described in lumens, and I have yet to learn how many lumens my living room needs.

There are still a few Imperial holdovers: some pubs serve craft beers in pints, people still ask about the weight of new-born babies in pounds, and computer typography is 72 (and a tiny bit) points to the inch. But on the whole, metric conversion is complete. Of course, there are lots of older buildings and a lot of industrial machinery, railway track, roads, bridges and dams built in Imperial measurements which will need maintaining for a long time, but they aren’t a major problem, and everything new is in metric measurements.

We have an entire generation of adults who have grown up using metric measures, and I don’t know anyone who would want to change back. And kids at school don’t need to wonder why there are sixteen ounces to the pound, fourteen pounds to the stone, and twelve inches to the foot.

Peter Goodyear

You can download a copy of the Metric Conversion Board’s final report, Metrication in Australia if you click on this link:

It’s a PDF document, fairly short, (127 pages,) but quite comprehensive in covering the background of the decision to change to metric, how the change  was accomplished and the notable successes and failures encountered on the way.

The story of how it came to be publicly available is interesting, and is documented here: