The Copley Medal is awarded to Sir Harold Jeffreys, F. R. S. During the past 45 years Sir Harold Jeffreys has carried out a long series of geophysical researches of fundamental importance. The problem of the internal constitution of the earth involves many disciplines, and it was his outstanding achievement to take the existing scattered researches and weld them into the coherent subject now called the geophysics of the solid earth. His book,
The earth
, now in its fourth edition, is still the standard work in this field. Jeffreys is best known as a theoretical seismologist. The Jeffreys travel-time tables, later revised in conjunction with K. E. Bullen, are not only the standard tables used in reductions of earthquake data, but are the basis of the best determinations of the elastic constants at all depths within the earth.
The Internal Constitution of the Earth
