These are called 'apparent' or 'false' assemblies). (some groups of pieces can be fit together without overlap internally,īut they interlock in such a way that they could never actually be put together from scratch that way. Pieces to interlock together, and (c) permits the pieces to be assembled and disassembled. These 32 internal cubes must be distributedĪmong the six pieces in some way that (a) permits every piece to remain undivided, (b) permits the six See above layer-by-layer diagram of an assembled burr - the internal cubies have dotted borders. In the burr shape there are 32 internal cube positions where the pieces would overlap, The burr shape is tricky to envision without an example in front of one, but it gets easier with practice. Overall set of possible such pieces (of a given length), and interlocked in a characteristic 2x2x2 Often but not always distinct, selected from the The burrs in this section are composed of six such pieces, One can visualize an individual burr piece as being composed of unit cubes arranged in a 2 x 2 x 2 n prism where n is greater than or equal to (and usually) 3.Ī solid piece will contain 24 unit cubes, and other piece types will have some of the cubes removed, resulting in notches. William (Bill) Cutler has performed (starting in 1975)Īnd the statistics cited below are based on his analysis. de Boer, and work by Tom O'Beirne and Arthur Cross,

There have been sporadic fits of research into the six-piece burr, including an extensive analysis by hand by the Dutch In his 1989 book Penrose Tiles to Trapdoor Ciphers, and most of the key puzzle authors mention the puzzle. Martin Gardner discusses burrs briefly (as an introduction to the puzzle sculptures of Miguel Berrocal) The Puzzling World of Polyhedral DissectionsĬontains a good introduction to this type of puzzle. Which is a modified and left-to-right inverted copy of aĮntitled 'L'Académie des Sciences et des Beaux Arts' by Sébastien Leclerc (or Le Clerc) (above on the right, detail at left). You can see a six-piece burr in the lower left area of theįrontispiece by John Sturt (above on the left), University of Wisconsin Digital Collection additional commentary at See the 1728 Cyclopedia of Ephraim Chambers Traces the six-piece burr back to Germany in 1698. Stewart Coffin discusses the six-piece burr in chapter 7, and reports that Jerry Slocum's New Findings on the History of the Six Piece Burr In his 2007 book Geometric Puzzle Design, (The text says the two other pieces are the solid key, and a copy of the piece labeled 3 in the diagram.) 1775) with a rather lengthy title that beginsĮngaños à Ojos Vistas, which translates as 'Deceptions in Plain Sight.' Occurs in a Spanish book, primarily on the topic of magic, from 1733 by the many-talented Pablo Minguet y Irol (b. One early depiction of the six-piece burr puzzle and specific pieces (in addition to an ad for the Large Devil's Hoof which is a 24-piece cage burr), The 1785 catalogue contains an ad for a traditional six-piece burr puzzle called 'The Small Devil's Hoof' Jerry Slocum and Dieter Gebhardt put together a compendium of puzzle advertisements found in theġ785 catalogue of the merchant Peter Friedrich Catel, who established a retail store in Berlin in 1780. His pieces seem to be though the diagrams are a bit hard to follow. XXXVI 'The Nut (or Six-piece) Puzzle.'Īnother six-piece burr is shown in the 1889 Chinese book Chinese and Western Magic With Diagrams: Compilation of Magic by Tang Yunzhou. (Keiser's pieces are the Chinese Cross set those pieces are shown in an 1857 book so Keiser did not invent them.)Ī traditional six-piece burr appears in Hoffmann's 1893 book Puzzles Old and New Keiser seems to have filed earlier but his patent was granted later. Keiser on March 16, 1915, and granted on April 2, 1918. (see Wei Zhang's Chinese Puzzles Blog andĪccording to the literature, the earliest relevant U.S. Known as 'The Huarong Path,' and the Tangram, and date it to ancient times Some say it is a Chinese invention, along with the Patience Tanglement, the Sliding Piece Puzzle Like other well-known vintage puzzles, the burr has acquired a probably-fanciful backstory, Supposedly whoever coined the term did so because the puzzle resembles the clinging Wyatt seems to use the term as if it was already commonly understood to apply. The term 'burr' is thought to have been first used by Edwin Wyatt in Puzzles in Wood (1928), but This puzzle is known by several names, including the 'puzzle knot,' the 'Devil's Knot' Any story about interlocking puzzles has to start with the traditional six-piece burr puzzle.

Foam cube puzzle dimension drawings