Q From Robert Williams: I’d seen the phrase jerry rigged and assumed it was related to WWII and the efforts of German soldiers to keep things running by patching things together. However I’ve also seen it spelled jury rigged. Where does this expression come from?
A It’s much older than World War Two. In the form jury rigged it’s from the days of sailing ships and dates from the early 1600s, if not earlier. It refers to a mast which is makeshift or a temporary contrivance, perhaps because the original was lost or damaged in a storm. Nobody knows for sure where it comes from. It has been suggested that it’s a shortening of “injury-rigged”, though that sounds to me like something invented well after the event. Another suggestion often made is that it comes from the old French ajurie, “aid, assistance”.
We also have the term jerry-built, for a house that’s been thrown up using unsatisfactory materials; this dates from the middle of the nineteenth century and is sometimes said to derive from the name of a Liverpool firm of builders (one with a reputation that has travelled, obviously) or possibly a contraction of Jericho (whose walls fell down, you will remember, at the blast of a trumpet). Neither has been substantiated, I’m sorry to say.
It’s possible that the confusion between jerry and jury is much older than we think and that jerry in jerry-built is actually a corruption of jury, in the modified sense of “inadequate” rather than “temporary”.
And, of course, Jerry has yet another meaning, the one you referred to in your question, an informal version of German, hence jerrycan. These three terms have got thoroughly mixed up in people’s minds, to the extent that we may never be able to disentangle them again.