In recent years there has been a striking improvement in science and mathematics instruction in many high schools. This improvement is not universal, and colleges are faced with the problem of freshmen entering with widely varying degrees of preparation.
Bill Putnam had a clear and lucid style and an ability to explain complex geological matters in a very readable and understandable way. We have tried to maintain that style while adding new data on developments and discoveries that have taken place in the fifteen years since the first edition was published.