In Dutch there is a saying: “Met twee maten meten”. It means that someone has double standards. Usually it’s bad when people say that about someone.
But I’ve got a confession to make: I’ve been maintaining double standards for years. And not just double, but numerous different standards…
Metric vs. Imperial
If you want to drop a bomb in a conversation with engineers, mechanics or luthiers, just start about different standards of measurement. They will probably begin to defend one of both systems, according to where they were born or grew up, and despise the other.
I was born in continental Europe, so we learned to work with the metric system and its decimal way of thinking. Nobody cared that there was another system used in different parts of the planet. Inches, feet, pounds, pints and yards were something of another world. We worked with meters, centimeters, millimeters, liters, grams and kilo’s.
You can live in either of both worlds and never know the other exists. Untill you come across something that behaves like an alien. You try to fix an old English car, and find out that your wrenches don’t fit. Or can’t find a replacement bolt for your bicycle. Most often this leads to makeshift solutions with adapters and converters and cursing the other system…
Different standards in lutherie.
At lutherie school in Belgium we also worked in the metric system. Historical instruments were copied after registration drawings others made. Often these showed quite irrational dimensions.
One of my classmates ordered a plan for a Martin OOO from Stewmac. He was very disappointed when it came in and all measurements were in inches. He printed a conversion table to hang next to it…
When I started to draw plans of vintage Danelectro, Silvertone and Harmony guitars, it soon became apparent that it made more sense to work with inches. The outlines and other dimensions of these instruments made no sense, until I realized that 76.2 mm equals 3″…
And shortly after that it also occurred to me that the unit of measurement was the key to unlock the design of earlier instruments. Like the Stradivari guitars.
Back in history
The metric system was introduced at the end of the 18th century in France. Due to the Napoleonic wars it was spread further over Europe. Before this every city and region had their own system, which would often lead to confusion. In the 6th and 17th century scientists like Simon Stevin and Christiaan Huygens would opt for a universal, decimal system, to improve international communication.
To me the ancient measurement systems are the basis for reconstructions of historical instruments. It becomes easier when you realize that Stradivari built his instruments with the “Braccio da Fabbrica, the Voboams in Paris used the “Pied du Roi” and the Ruckers in Antwerp measured their harpsichords in “Voeten”. All split up in either 8, 10, 11 (!) (the Antwerp Voet) or 12 divisions. At first this seems needlessly difficult, but when you start to work with them it starts to make sense. I’ve used the different systems in the shop, but was always converting it back to millimeters. It works, but is still a lot of work. To really get to grips with these systems I needed to have some rulers.
As originals are very scarce and expensive (and it wouldn’t be appropriate to use them in the shop) I needed to make some myself. This is probably the way the old makers did it themselves. In the foundations of clock tower from Cremona for example, is a rough chiseled “Braccio da Fabbrica”. A tradesman who had to work with the measurements of the city could go to the tower to get the local standard.