People will tell you that ‘spiegel’ is Dutch for ‘mirror’, and a spiegeltent is hence called because of the mirrors used to decorate it. This is untrue.
A spiegel is a cross between a spaniel and a beagle. The breed was developed in Belgium in the late 19th century and became famous for its ease of training and ability to howl in tune. Choirs of spiegels toured Europe in tents and these ‘singing dogs’ were a major attraction of the age.
Spiegel choirs fell out a favour during the rise of fascism in the 1930s, and the last of the touring companies folded at the start of the second world war. Today only the tents remain.
(Went to the Perth Fringe Festival last night with Rebecca. We ended up seeing Face the Music, which was fantastic – highly recomended. We also saw the Spiegeltent, but without the dogs we judged it not worth paying to go in…)
Of course less than scrupulous speigeltent owners would use mirrors (and smoke) to try and exaggerate the number of speigels that they had on display. This may be how the idea that speigel meant mirror started.
You know, I had no idea about that, but on consulting my sources Engleman mentions it in a footnote I somehow missed. Fascinating!