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793.73 “Shelving 101”

Douglas Davey is our cryptic crossword creator and puzzler extraordinaire. In this entry of his monthly puzzle column, 793.73, Douglas challenges readers with a dastardly delightful shelving-themed logic puzzle. See if you can determine the correct appearance of the shelving unit he describes.

As always, follow the link above the puzzle for a printable version and the link below it for the answers.

Having just emerged from the non-stop thrill-ride that is a major collection shift, I was struck by the need for consistency in language that such a project created. After all, what is a shelf? Such lofty thoughts inspired me to torture entertain my fellow library professionals with a shelving-themed puzzle.

Below you will find some terminology, followed by a list of statements, placed in an extremely unhelpful order. If followed correctly, and with some logical deductions, they will allow you to create an accurate drawing of the shelving and answer the bonus question as well.

Printable Version >>


For the purposes of this puzzle:

  • A shelf is a single horizontal book storage unit
  • A bay is a vertical unit containing multiple shelves. The bottom of a bay is always a shelf. 
  • A face is a set of bays set side by side
  • A run is a set of two faces placed back-to-back 
  • A double-faced bay is two bays placed to back-to-back

The Puzzle

  • A-1 has 2 shelves, B-1 has 6
  • The run has six bays in total
  • Each bay has between 1 and 6 shelves 
  • There is only one run
  • The first shelf of the second bay is named A-2-1.
  • The faces are the same length
  • All shelves and their materials run top to bottom, left to right. 
  • Every double-faced bay has the same number of shelves
  • Face B has twice as many shelves as A
  • No two bays have the same number of shelves

Bonus question: If every shelf has exactly 37 books stored on it, on what shelf (using the naming convention above) would you find the 500th book?

Answer Key >>

Feature image: “Crosswords” by Jessica Whittle Photography and is licensed under CC BY-NC-ND 2.0

Douglas Davey has been a professional librarian for over 20 years and is currently the Manager, Library Services at Whitchurch-Stouffville Hills Public Library. Currently, he is the Vice President of the Ontario Public Library Association and the OPLA Children’s or Youth Librarian of the Year. He is also an author of fiction for teens, and a total nerd for horror, fantasy, and sci-fi. He lives in Guelph with his family.

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