Sources page biographical material

6.AI. TRICK JOINTS
S&B, pp. 146 147, show several types.

These are often made in two contrasting woods and appear to be physically impossible. They will come apart if one moves them in the right direction. A few have extra complications. The simplest version is a square cylinder with dovetail joints on each face -- called common square version below. There are also cases where one thinks it should come apart, but the wood has been bent or forced and no longer comes apart -- see also 6.W.5.

See Bogesen in 6.W.2 for a possible early example.

Johannes Cornelus Wilhelmus Pauwels. UK Patent 15,307 -- Improved Means of Joining or Fastening Pieces of Wood or other Material together, Applicable also as a Toy. Applied: 9 Nov 1887; complete specification: 9 Aug 1888; accepted: 26 Oct 1888. 2pp + 1p diagrams. It says Pauwels is a civil engineer of The Hague. Common square version.

Tom Tit, vol. 2. 1892. Assemblage paradoxal, pp. 231-232. = K, no. 155: The paradoxical coupling, pp. 353 354. Common square version with instructions for making it by cutting the corners off a larger square.

Emery Leverett Williams. The double dovetail and blind mortise. SA (25 Apr 1896) 267. The first is a trick T joint.

T. Moore. A puzzle joint and how to make it. The Woodworker 1:8 (May 1902) 172. S&B, p. 147, say this is the earliest reference to the common square version -- but see Pauwels, above. "... the foregoing joint will doubtless be well-known to our professional readers. There are probably many amateur woodworkers to whom it will be a novelty."

Hasluck, Paul N. The Handyman's Book. Cassell, 1903; facsimile by Senate (Tiger Books), Twickenham, London, 1998. Pp. 220 223 shows various joints. Dovetail halved joint with two bevels, p. 222 & figs. 703-705 of pp. 221-222. "... of but little practical value, but interesting as a puzzle joint."

Dudeney. The world's best puzzles. Op. cit. in 2. 1908. Shows the common square version "given to me some ten years ago, but I cannot say who first invented it." He previously published it in a newspaper. ??look in Weekly Dispatch.

Samuel Hicks. Kinks for Handy Men: The dovetail puzzle. Hobbies 31 (No. 790) (3 Dec 1910) 248-249. Usual square dovetail, but he suggests to glue it together!

Dudeney. AM. 1917. Prob. 424: The dovetailed block, pp. 145 & 249. Shows the common square version -- "... given to me some years ago, but I cannot say who first invented it." He previously published it in a newspaper. ??as above

Anon. Woodwork Joints, 1918, op. cit. in 6.W.1. A curious dovetail joint, pp. 193, 195. Common square version. Dovetail puzzle joint, pp. 194 195. A singly mortised T joint, with an unmortised second piece.

E. M. Wyatt. Woodwork puzzles. Industrial Arts Magazine 12 (1923) 326 327. Doubly dovetailed tongue and mortise T joint called 'The double (?) dovetail'.

Sherman M. Turrill. A double dovetail joint. Industrial Arts Magazine 13 (1924) 282 283. A double dovetail right angle joint, but it leaves sloping gaps on the inside which are filled with blocks.

Collins. Book of Puzzles. 1927. Pp. 134 135: The dovetail puzzle. Common square version.

E. M. Wyatt. Puzzles in Wood, 1928, op. cit. in 5.H.1.

The double (?) dovetail, pp. 44 45. Doubly dovetailed tongue and mortise T joint.

The "impossible" dovetail joint, p. 46. Common square version.

Double lock dovetail joint, pp. 47 49. Less acceptable tricks for a corner joint.

Two way fanned half lap joint, pp. 49 50. Corner joint.

A. B. Cutler. Industrial Arts and Vocational Education (Jan 1930). ??NYS. Wyatt, below, cites this for a triple dovetail, but I could not not find it in vols. 1 40.

R. M. Abraham. Prob. 225 -- Dovetail Puzzle. Winter Nights Entertainments. Constable, London, 1932, p. 131. (= Easy to do Entertainments and Diversions with coins, cards, string, paper and matches; Dover, 1961, p. 225.) Common square version.

Abraham. 1933. Prob. 304 -- Hexagon dovetail; Prob. 306 -- The triangular dovetail, pp. 142 143 (100 & 102).

Bernard E. Jones, ed. The Practical Woodworker. Waverley Book Co., London, nd [1940s?]. Vol. 1: Lap and secret dovetail joints, pp. 281 287. This covers various secret joints -- i.e. ones with concealed laps or dovetails. Pp. 286-287 has a subsection: Puzzle dovetail joints. Common square version is shown as fig. 28. A pentagonal analogue is shown as fig. 29, but it uses splitting and regluing to produce a result which cannot be taken apart.

E. M. Wyatt. Wonders in Wood. Bruce Publishing Co., Milwaukee, 1946.

Double double dovetail joint, pp. 26 27. Requires some bending.

Triple dovetail puzzle, pp. 28 29. Uses curved piece with gravity lock.

S&B, p. 146, reproduces the above Wyatt and shows a 1948 example.

W. A. Bagley. Puzzle Pie. Op. cit. in 5.D.5. 1944. Dovetail deceptions, p. 64. Common square version and a tapered T joint.

Allan Boardman. Up and Down Double Dovetail. Shown on p. 147 of S&B. Square version with alternate dovetails in opposite directions. This is impossible!

I have a set of examples which belonged to Tom O'Beirne. There is a common square version and a similar hexagonal version. There is an equilateral triangle version which requires a twist. There is a right triangle version which has to be moved along a space diagonal! [One can adapt the twisting method to n-gons!]

Dick Schnacke (Mountain Craft Shop, American Ridge Road, Route 1, New Martinsville, West Virginia, 26155, USA) makes a variant of the common square version which has two dovetails on each face. I bought one in 1994.