London, The Tallis Press, 1905. First editions, first impressions. Hardbacks. Very good copies. Three volumes, described thus. (1) A very good copy inscribed by the author to the front endpaper, dated in the year of publication. Competition return slip still present. A little ageing to the leaves, and some toning and bumping to the spine. (2) A very good copy, though slightly poorer than copy #1. This copy has two leaves (3pp) of analysis to the rear, tipped in. As noted on the upper board, a competition was launched to resolve the mystery. The return slip has been removed and presumably posted. The solution stapled in is presumably a copy that the reader made of his solution. No indication of authorship. Front hinge pulled, spine a touch toned and bumped. (3) Very good. Presumably a slightly later issue with the competition details having been covered by an illustrated plate. The competition having likely ended. Probably the same same impression as the other two, just issued later. Some foxing and a little toning to the spine, competition slip removed - presumably by the publisher. A nice set. [9132, Hyraxia Books].