Martin Gardner's father once showed him a magic trick when he was a little boy. Young Martin was fascinated to see physical laws seemingly violated and this led to a lifelong passion for magic and illusion. He wrote for a magic magazine in high school and worked in a department store demonstrating magic tricks while he was at the University of Chicago. The very first thing that Martin Gardner ever published (at the age of fifteen) was a magic trick in "The Sphinx", the official magazine of the Society of American Magicians. He focused mainly on micromagic (table or close-up magic) and, from the 1930s on, published a significant number of original contributions to this secretive field. Magician Joe M. Turner said, "The Encyclopedia of Impromptu Magic", which Gardner wrote in 1985, "is guaranteed to show up in any poll of magicians' favorite magic books." His first magic book for the general public, "Mathematics, Magic and Mystery" (Dover, 1956), is still considered a classic in the field. He was well known for his innovative tapping and spelling effects, with and without playing cards, and was most proud of the effect he called the "Wink Change".