Inge Lehmann

Inge Lehmann (May 13,1888-February 21, 1993), Fellow of the Royal Society (London) 1969, was a Danish seismologist who, in 1936, argued that the Earth must not only have a molten interior, but a solid core at the center, which deflects P waves. She also wrote a book called P, which dealt with P waves and other aspects of seismography.

External link:

" class="external">http://www.physics.ucla.edu/~cwp/articles/bolt.html