Puzzle design by James Ferguson, object design by Peter Knoppers and Oskar, made by Buttonius Puzzles & Plastics. From the attached instructions, "Henry Dudeney presented this 'Mechanical Paradox' and its solution in Modern Puzzles (1926).""This remarkable device was contrived by James Ferguson in 1751 as a challenge to a sceptical watchmaker during a metaphysical controversy. 'Suppose', Ferguson said, 'I make one wheel as thick as 3 others and cut teeth in them all, and then put the three w...

This puzzle is a exchange puzzle by Saul Bobroff for the International Puzzle Party 28 held in Prague, Czech Republic 2008 Goal: The 4 street elbows are held together only by their 1”-18 threads. How is put together? Packaging: Zip lock bag.Preliminary estimate of shipping costs from the Netherlands.   Netherlands: from 0 - 2 kg, max. approx $ 12.00 Europe 1: from 0 - 2 kg, max. approx $ 23.00 to Belgium, Germany, France, (incl. Corsica and Monaco), Italy (excl. S...

All three of the classics!Impossible Convex DovetailImpossible Concave DovetailImpossible T DovetailNot so much puzzles as impossible objects (although each contains a cute trick for removing the green dovetailed piece), by the prolific Dutch puzzle designer and manufacturer, Wil Strijbos.  I purchased these directly from Wil at IPP32 in Washington DC in 2012.  They are each in mint condition.  Note that when available, these sell for around $72 (US) each on the PuzzleMaster web site.I will s...

Double Dovetail Square is number 1 in Robert Rose's MBP (Mental Block Puzzle) series. Robert sold a bunch of his puzzles at IPP 23 in Chicago and, sadly, passed away before being able to attend another.  The red piece is inscribed, on the inside,  with "DDSQ" & "MBP1".  This impossible object puzzle is in perfect condition.This puzzle is in perfect condition with no fading of the vibrant turquoise and pink anodising. It is by no means a difficult puzzle and should be considered an impossible ...

Triple Dovetail Triangle is number 3 in Robert Rose's MBP (Mental Block Puzzle) series. Robert sold a bunch of his puzzles at IPP 23 in Chicago and, sadly, passed away before being able to attend another.This puzzle is in perfect condition with no fading of the vibrant turquoise and pink anodising. It is by no means a difficult puzzle and should be considered an impossible object rather than a tricky puzzle. It does make a brilliant fidget toy and displays beautifully!***************************...