well as other mathematics books. The paintings were inspired by famous mathematicians such as Galileo, Euclid, Descartes, and many more, and the titles of said paintings are references to each mathematician--"Proof of the Pythagorean Theorem" for Euclid, "Pendulum Momentum" for Galileo, and "Square Root of Two" after Descartes. Later, he began to construct using his own inventions. Most of Johnson's abstract images are painted with house paint on the rough side of a two-by-three foot piece of masonite, save those he enlarged to four-by-four, he explained in a letter. Johnson made an effort to differentiate his paintings from contemporary art in that his are based on the mathematics of geometry, not solely the shapes. In his 1971 article titled "Geometric Geometric Painting," published in Leonardo, Johnson describes this type of geometric painting as using shapes and lines to experiment with color and optic illusion for decoration, the evocation of emotion, representation of ancient symbols or other purposes unrelated to geometry. From 1965 until his death in 1975 Crockett Johnson painted over 100 works relating to mathematics and mathematical physics. Gallery of Mathematical paintings https://americanhistory.si.edu/collections/object-groups/mathematical-paintings-of-crockett-johnson?ogmt_page=mathpaintings-resources https://americanhistory.si.edu/collections/object-groups/mathematical-paintings-of-crockett-johnson?ogmt_page=mathpaintings-introduction https://americanhistory.si.edu/connect/podcasts/history-explorer-crockett-johnson-art-and-math-days-sputnik Works Barnaby (1943) Barnaby and Mr. O'Malley (1944) Willie's Adventures, Three Stories by Margaret Wise Brown, (1944), illus. by Johnson Ruth Krauss, The Carrot Seed (1945), illus. by Johnson Harold and the Purple Crayon (1955) Is This You? (1955), co-written with Ruth Krauss Franklyn M. Branley, Eleanoe K. Vaughn, Mickey's Magnet (1956), illus. by Johnson Barkis: Some precise and some speculative interpretations of the meaning of a dog's bark at certain times and in certain (illustrated) circumstances (1956) Harold's Fairy Tale (Further Adventures with the Purple Crayon) (1956) Harold's Trip to the Sky (1957) Terrible, Terrifying Toby (1957) Time for Spring (1957) Bernadine Cook, The Little Fish That Got Away (1957) Harold at the North Pole (1958) The Blue Ribbon Puppies (1958) Ellen's Lion: Twelve Stories (1959) The Frowning Prince (1959) Harold's Circus (1959) Will Spring Be Early? or Will Spring Be Late? (1959) A Picture for Harold's Room (1960) Harold's ABC (1963) The Lion's Own Story: Eight New Stories about Ellen's Lion (1963) We Wonder What Will Walter Be? When He Grows Up (1964) Castles in the Sand (1965), illus. by Betty Fraser The Emperor's Gifts (1965) Barnaby #1: Wanted, A Fairy Godfather (1985) Barnaby #2: Mr. O'Malley and the Haunted House (1985) Barnaby #3: Jackeen J. O'Malley for Congress (1986) Barnaby #4: