Wednesday, December 11, 2013
You may have noticed that I sometimes give dimensions in the old ‘Imperial’ units of inches, and sometimes in Metric. In England, my generation grew up with the Imperial system, not only just yards, feet and inches, but also a rich trove of other units passed down from time immemorial: in school we gained familiarity with rods, chains and furlongs, and learned how these related to areas such as the acre, and longer measurements like the mile.
I was already adult before the Metric System was introduced nationwide. The changeover in the United Kingdom was never entirely achieved. The same attempt was made with more, but still limited, success, in Canada. This transition was made more difficult by the presence of our neighbour to the south. The U.S.A. does not yet embrace the metric system, so proximity obliges us to be able to function in both systems.
Anyway, when forty years ago I began to make furniture for a hobby, I began by using Imperial units. I quickly found though, that when crafting small items, working in millimeters was far simpler, more precise and less likely to result in error. On the other hand, when measuring large components I found feet and inches easier to visualize. So I ended up using both systems, often in the same piece of work. So, as an example, I may refer to a floorboard being four feet long, nine inches wide and 22 millimeters thick. Happily, I am supported in this choice of method by the availability of measuring tapes and rulers which have Metric down one side and Imperial markings on the other. Obviously, other people have arrived at the same solution. I trust the reader can make the jump.
The reason I mention this now is because you will see in the next part of 'The Georgian Bed' that I habitually use whole millimetres when I am measuring the diameters and spacings of the various parts of a turning. Easier to read when laying calipers on the rule, and no chance of mistaking 11/16ths of an inch for 13/16s!