It always amazes me how we — the human race — have such an ability to make things confusing. When it comes to currency, for example, I grew up in England in the days of “pounds, shillings, and pence.” As I wrote in my column on Cool Mechanical Calculators, “The way in which this worked was that there were 12 pennies in a shilling (also called a bob) and 20 shillings (240 pennies) in a pound.”
One problem is that we don’t like change and we tend to cling to whatever we grew up with. For example, when Great Britain retired the concept of pounds, shillings, and pence in 1971 and we officially adopted a decimal system in which a pound equaled 100 pennies, the majority of British citizens fought this move toward decimalization tooth-and-nail claiming that the new scheme was far too complicated and would never catch on!

According to Statista.com: “Only three countries — the U.S., Liberia, and Myanmar — still (mostly or officially) stick to the imperial system, which uses distances, weight, height, or area measurements that can ultimately be traced back to body parts or everyday items.”
This is as may be, but my chum Martin Rowe just sent me an email containing a mind-boggling chart titled “How to measure things like a Canadian,” which I just reproduced here for your delectation and delight. (See also What the FAQ are Celsius and Fahrenheit? and What the FAQ are Kelvin, Rankine et al?)
In his email, Martin noted, “In the 1970s, there was a push by the American government to get us to convert to metric. TV weather even gave the temperature in F and C. No more. The only thing that came out of that was the 2-liter bottle of soda.” Now I come to think about it, that’s true — 2-liter bottles of soda are the only things I’ve seen in metric since I moved to the USA 31 years ago.
I emailed my chum Aubrey Kagan, who currently hangs his hat in Canada, to ask, “Is this chart from the 1970s or is it still valid today?” Aubrey replied, “The chart is still valid today. The mismatch of engineering measurements created much checking when I was working on the arm for the International Space Station. All the mechanical dimensions from NASA were in FPS including nut/bolt threads. However, because my project was Canadian Government funded, all the CSA (Canadian Space Agency) measurements had to be in MKS. We really had to be careful. You didn’t want to get up there and find out the nut didn’t fit…”
How about you? Do you have any tales you’d care to share regarding nuts that didn’t fit or anything else of a unit conversion nature?
This is spot on, and so funny i can’t read the word through my tears.
I didn’t mean to make anyone cry 🙂
I was just old enough to remember the move to “new money” in the UK in the 1970’s. I can also remember my grandad sending me to the ice cream van armed with an old 1 penny coin and the guy refusing to accept it as it was “old money”. That was one of my first memories of being embarrassed in front of a queue of people. Growing up I’ve personally suffered from being a child between two worlds. That of my father being imperial, and school teaching metric, and I’ve paid for this through my life; like being a victim of the comprehensive education system wasn’t punishment enough. Using a tape measure now means using whichever number or tape mark (irrespective of measurement unit) is closest to the thing I’m measuring, which has led to obvious mistakes. Measure length of pipe; 67 inches, have drink of coffee, move cat out of the way, cut pipe to 67 CM, scratch head because pipe that was expertly measured doesn’t fit. Check wall hasn’t moved, go to hardware store to buy new pipe noting that car dashboard reminds me I’m doing 50 MPH but only have 50 km of fuel remaining, miss turning off the motorway (Interstate) whilst trying to work out how many hours I can keep driving for before I run out of fuel (because I’m so screwed up over units of measurement that I now judge distance by how long it will take me to drive somewhere), and run out of fuel before the next off-ramp.
Remember that I commenced this column saying “It always amazes me how we — the human race — have such an ability to make things confusing.”
I assume you know about this fiasco? https://www.simscale.com/blog/2017/12/nasa-mars-climate-orbiter-metric/
Yes — I heard about that — I wouldn’t want to be the engineer responsible for that one 🙂
My mother combined U.S. and Scandinavian cooking recipes. U.S. recipes usually measured ingredients by volume. Scandinavian recipes often measured the same ingredients by weight.
Gerber-format PCB artwork files have units-indicator line %MOIN% meaning positions in mils = thousandths of an inch, or %MOMM% meaning positions in millimeters. I remember millimeter-dimensioned IC packages flummoxing the users of inch-dimensioned PCB design programs.
I’d go to SI units for PCBs in an instant if I didn;t make so much use of 0.1″ pitch headers and suchlike LOL
The U.S.S.R. copied U.S. 0.1-inch pitch packages. The U.S. inch is 25.4 millimeters. The U.S.S.R. used the Soviet inch which was 25.0 millimeters.
How did that work out for them?
U.S.S.R. DIP packages would plug into U.S.S.R. PCBs or sockets, but not into U.S. PCBs or sockets. U.S. DIP packages would plug into U.S. PCBs or sockets, but not into U.S.S.R. PCBs or sockets.
Did they do that deliberately — or was it just a monumental mistake?