When you’ve read the 60 stories in the Canon a few times, or maybe on the very first reading, you may start to wonder about some of the terms used, some of the places mentioned, some of the people involved and some of the quotations given.

For example, would you know what a “gasogene” [MAZA, SCAN] was, where the Grimpen Mire [HOUN] is, and who our landlady was (Mrs Hudson or was it Mrs Turner [SCAN]?)

Over the years several authors have studied the Canon in an attempt to explain, or unearth, the real meaning and the real people behind the stories and to explain some of the parenphenalia of Victorian England. They produced what are referred to as the “Annotated Sherlock Holmes”.

First of note was William Sabine Baring-Gould’s Annotated Sherlock Holmes. Originally in two volumes and later combined into a single volume, Baring-Gould organised the stories according to the dates during which the cases appeared to have taken place. As I have noted elsewhere, this isn’t always clear (sometimes for good reason) and Baring-Gould’s deductions are not always in agreement with other chronologies. Nevertheless he provides useful extra detail about each case.

My own personal favourite is The Oxford Sherlock Holmes, edited by Owen Dudley Edwards, which produces the stories in their more usual order of publication and in nine volumes. This set I have used so much that some of the pages are coming loose. Each volume is a very handy pocket size that makes them ideal for travelling. A paperback version has been published and I may soon need to replace my hardback version with this. Both the hardback and paperback sets will appear in my library opposite (listing them here would take up too much space).

Finally amongst these extended works is Leslie S Klinger’s Annotated Sherlock Holmes. It’s a set of three very large books (the first two covering the short stories and the third the novels) and condenses what had been written in his The Sherlock Holmes Reference Library where, much like The Oxford Sherlock Holmes, each of the nine volumes of the Canon (four novels and five volumes of short stories) are analysed. Although expensive, this Annotated Sherlock Holmes, like the Oxford Sherlock Holmes, is still in print. The Baring-Gould volumes are only available second hand.

There are also several encyclopedias, including The Sherlock Holmes Encyclopedia by Matthew Bunson, The Sherlock Holmes Encyclopedia by Orlando Park and, my favourite, The Ultimate Sherlock Holmes Encyclopedia by Jack Tracy (you may be able to find a previous version as The Encyclopedia Sherlockiana).

If you have trouble finding these books at your local second-hand bookshop, try my friend’s book shop at The Omnivorous Reader.

By the way, a gasogene is a device for producing soda, the predecessor of the soda syphon. It consisted of two glass spheres, one above the other. The lower one contained water and the upper one containing carbonate and acid. When water is introduced into the uppper chamber, gas is produced which aerates the water in the lower chamber. It can then be drawn off and added to a drink.

The Grimpen Mire is on Dartmoor and, in The Hound of the Baskervilles, Holmes and I walked carefully along the path amongst its green scummed pits and foul quagmires where rank reeds and lush, slimy water-plants sent an odour of decay and a heavy miasmatic vapour into our faces, while a false step plunged us more thigh-deep into the dark, quivering mire, which shook for yards in soft undulations around our feet. Its tenacious grip plucked at our heels as we walked, and when we sank into it it was as if some malignant hand was tugging us down into those obscene depths, so grim and purposeful was the clutch in which it held us. Some believe this to be the area around Fox Tor.

Mrs Hudson occasionally went away for a few days and one of her friends would attend to our needs. That was the case on a couple of occasions, during A Scandal in Bohemia and maybe in The Empty House when Mrs Turner stood in for Mrs Hudson.