one another. They are arranged in a line parallel to the zodiac, and the middle one (Saturn itself) is about three times the size of the lateral ones." He also described the rings as Saturn's "ears". In 1612 the Earth passed through the plane of the rings and they became invisible. Mystified, Galileo remarked "I do not know what to say in a case so surprising, so unlooked for and so novel." He mused, "Has Saturn swallowed his children?" — referring to the myth of the Titan Saturn devouring his offspring to forestall the prophecy of them overthrowing him. He was further confused when the rings again became visible in 1613. Early astronomers used anagrams as a form of commitment scheme to lay claim to new discoveries before their results were ready for publication. Galileo used the anagram "" for Altissimum planetam tergeminum observavi ("I have observed the most distant planet to have a triple form") for discovering the rings of Saturn. In 1657 Christopher Wren became Professor of Astronomy at Gresham College, London. He had been making observations of the planet Saturn from around 1652 with the aim of explaining its appearance. His hypothesis was written up in De corpore saturni, in which he came close to suggesting the planet had a ring. However, Wren was unsure whether the ring was independent of the planet, or physically attached to it. Before Wren's theory was published Christiaan Huygens presented his theory of the rings of Saturn. Immediately Wren recognised this as a better hypothesis than his own and De corpore saturni was never published. Robert Hooke was another early observer of the rings of Saturn, and noted the casting of shadows on the rings. Huygens' ring theory and later developments Huygens began grinding lenses with his brother Constantijn in 1655 and was able to observe Saturn with greater detail using a 43× power refracting telescope that he designed himself. He was the first to suggest that Saturn was surrounded by a ring detached from the planet, and famously published the anagram: "". Three years later, he revealed it to mean Annuto cingitur, tenui, plano, nusquam coherente, ad eclipticam inclinato ("[Saturn] is surrounded by a thin, flat, ring, nowhere touching, inclined to the ecliptic"). He published his ring theory in Systema Saturnium (1659) which also included his discovery of Saturn's moon, Titan, as well as the first clear outline of the