coin trick to his children and subsequently got the idea for the thaumatrope. Claudet also noted in 1867 that the thaumatrope could create a three-dimensional illusion. A spinning rectangular thaumatrope with the alternating letters of the name "Victoria" on each side, showed the full word with the letters at two different distances from the observer's eye. If the two strings of the thaumatrope are attached to the same side of the card the thickness of the card accounts for a small difference in the distances when each side is visible. Commercial production The first commercial thaumatrope was registered at Stationers' Hall on 2 April 1825 and published by W. Phillips in London as The Thaumatrope; being Rounds of Amusement or How to Please and Surprise By Turns, sold in boxes of 12 or 18 discs. It included a sheet with mottoes or riddles for each disc, often with a political meaning. Paris was widely regarded as the author, but wasn't mentioned on the product or its packaging and he later claimed in a letter to Michael Faraday "I was first induced to publish it, at the earnest desire of my late friend Wm Phillips. (...) I may add that I never put my name to it". The steep price of a set (seven shilling for 12 discs or half a guinea for 18) was criticized, half a guinea would have been about a week's pay for an average worker. It was also defended: its inventor should be able to earn something from his invention while it was new, before it was widely copied as seen before with the kaleidoscope. Paris later claimed he gained £150,- from its sales in the United Kingdom. As expected, pirate copies soon became common and were much cheaper. For instance the 'Thaumatropical Amusement' was available in boxes of six discs for one shilling. Although the toy became very popular, original copies are now very rare; only one extant set produced by W. Phillips is currently known (in the Richard Balzer collection) and one single disc is at the Cinématheque Française. Other early publishers across the continent included Alphonse Giroux & Compagnie in France and Trentsensky in Austria. In 1833 these companies would be the very first publishers of the next big "philosophical toy" craze: the Phénakisticope. Animation In the first 1827 edition of "Philosophy in Sport" John Ayrton Paris described a version with a circular