Concise Metric Symbols

By The Metric Maven

Bulldog Edition

My Stepfather sent me an interesting metric artifact that reminds me of the Rosetta Stone. First a bit of background.  It was not uncommon in the past that plastic 75 mm x 110 mm card-like cases, which have a plastic card inside of them, with technical information were available for sale, and for institutional promotion. A good college friend had one that I was jonesen for in the worst way. I did make a photocopy of it, well part of one side of it. I have taken a photo and the image is below. I was completely enamored, but had no idea how to obtain one, and my friend could not recall where she obtained it. The amount of information on this small plastic card was amazing, and with young eyes, provided easy access for any science or engineering exam.

The edge of this image of the plastic card has a copyright symbol, a year, 1968, and Concise International CO., LTD. The internet has made any esoteric item’s history easily found. The Smithsonian has a page with the exact model my friend owns. It is the Concise 6000 Science Tables and Circular Slide Rule:

Concise Science Tables and Circular Slide Rule – Front View

The outer plastic case has a four inch rule on one side, and a 10 cm (tsk…tsk) or 100 mm on the other. The front has a circular slide rule, and the back a copy of the periodic table of the elements. At the top of the table is a Fahrenheit to Celsius conversion chart. The plastic card inside contains an incredible amount of mathematical, chemical and physical data, as well as conversion factors. The International Slide Rule Museum
has an eclectic group of Concise products. They were made for a number of technical institutions as promotional items. I was quite interested in the one which was created for electrical engineers:

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There are many different versions shown online, but my Stepfather sent me one that is unique to me. The front side of the plastic cover is shown below:

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I have essentially zero understanding of the Japanese language, so the ideographs for metric quantities caught my attention immediately. Below are the symbols for lengths.

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What is interesting is the symbol for meter is a single character. That character has another to the right of the meter symbol for millimeter, and a different symbol to the right for Kilometer. The values are nice and concise and seem metric in form, but the prefix is on the suffix side. The symbols for inch, foot, yard, chain and mile require three symbols it appears. They are clearly foreign to the Japanese and require more description than their metric counterparts. The Japanese lengths tend to have more compact symbols, but not always. According to Wikipedia the values are:

bu = 3.03 mm

sun = 30.3 mm

shaku = 303 mm

ken = 1818 mm

cho = 109.1 meters

ri = 3.927 Kilometers

The values for mass are given as:

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We can see the carat has a very complex symbol. The symbol for the gram is distinctive and follows a similar suffix rather than prefix location for modifying the gram. Despite the designation of t for tonne, the symbol looks more like that for Megagram, Mg, and in my view should have been designated as such. The grain, ounce, pound (assuming US?) have complex symbols, and the long and short ton have even more complex looking symbols. The native Japanese mass values appear far more concise than the Ye Old English ones. Their values are:

fun = 375 mg

me = 3.75 g

kan = 3.75 Kg

kin = 600 grams

The back side of the card holder has more equivalent values:

The cubic and capacity are at bit curious:

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The symbol for liter has a nice look of a volume. The symbol is shown in the symbol for cubic centimeter, but it would have been nice to have it be a milliliter with a two symbol combination as with millimeter and Kilometer. The liter symbol appears to be included in  the symbol for cubic meter. Somehow there appears to be an understanding they are all equivalent to multiples of the volume of a liter. I will not attempt to offer values for the Japanese volumes.

The front of the interior plastic card has length and mass conversions:

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The back has area and volume equivalents.

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While the internet has made such conversion charts mostly obsolete, it is interesting to look at some of the archaic values. The one which is new to me is the register ton, which is equal to one hundred cubic feet. According to Wikipedia, this volume unit was used to describe a ship’s total interior volume.

It is interesting that even without any understanding of Japanese, they appear to have used a logical symbolism that can be, to a certain extent, teased from the context. Mathematics may be the universal language, but the metric system is the universal relationship between the physical world and mathematics—well—except in the US.

3 thoughts on “Concise Metric Symbols

  1. The Japanese symbols for yard, inch, and foot (and it looks like almost all English customary quantities) are phonetic transliterations of English written in katakana (one of the syllabaries used to write Japanese) [This is common since Japanese borrows a lot of words, and using katakana sort of emphasizes the “foreignness” of the word]. So for yard, ヤード is approximately the sound “yah-doh”. Interestingly, the symbol for meter, 米, is also used for wheat and the United States (see jisho.org/search/米 for more info).

    As for the single symbol SI prefix units, I don’t know that I’ve seen them used often. The symbols for milligram or centimeter [centimeters are usually called センチ (“senchi”)] I definitely haven’t seen before, but it may be that I just haven’t seen them.

    Also interesting is that long ton 英トン literally translates to “English ton’ whereas the short ton トン(米) means “ton (US)”.

    • Sorry, I meant 米 is the symbol used for meter, rice, and the US. I don’t know why I said wheat.

  2. Interesting historical device. Note that although copyright is 1968, the values for mass and length are different for the US and UK and precede the international agreements reached in1958 (adopted US 1959-07-01) that 1 ft = 0.3048 m, exactly. 1 lbm = 0.453 592 37 kg, exactly. The US value for length seems to be the Survey or Mendenhall (1893) foot, the UK a different value (I think it correct for that era, but I don’t know). The length difference also affects area and volume charts.

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