This boundary is known as the Bullen discontinuity, or sometimes as the Lehmann discontinuity. A few years later, in 1940, it was hypothesized that this inner core was made of solid iron; its rigidity was confirmed in 1971. The outer core was determined to be liquid from observations showing that compressional waves pass through it, but elastic shear waves do not â or do so only very weakly.
Flannery Literary is a Chicago area literary agency representing writers of books for children and young adults because the most interesting, well-written, and time-honored books are written with young people in mind.
Order of Laura Ingalls Wilder Books Laura Ingalls Wilder (1867-1957) was an American author of the Little House series â a series of childrenâs novels based on her own life growing up in a pioneer family. Before gaining fame as a novelist, Laura worked as a teacher as well as on the farm.