The author Margaret Mahy employs language in many ways in this story. One of the most prevalent and key among these uses is Tycho Potter's obsession with quotes from historical figures. Through Tycho, the author is able to add another dimension to the narrative without extensive use of expository paragraphs. In doing this, Mahy is, once again, able to maintain the flow of the narrative and the intimacy of the story. Tycho's obsession with language extends into his pre-occupation with the book after which Mahy's novel is named, Catalogue of the Universe. Here again, Mahy uses the printed language as a symbol for something larger: near the end of the novel, Tycho comes inside after looking at the stars, with his book at his side.