This book is proving a fascinating introduction to Dupin especially for one who knows very little French.

I am intrigued by the opening phrase in Une apparence de soupirail 34 :-

Girolle au--dessus du vide. / A skirret over the emptiness.

Girolle as far as I have been able to ascertain is either a chanterelle or a cutter for a Swiss cheese invented in the same year as the poem was first published in French. Whilst skirret has the possibility of being a mason's tool used when laying out the foundations of a house, or a hardy root vegetable. Skirret is new to me but somehow has the same feel as zigzag and is so beautifully echoed here by script.

Any comment on the use of skirret in this context would be much appreciated