In a sensible revamping of the series, several measures have been taken which will make these more practical for libraries and more useful to students; the dimensions have been changed, resulting in a thicker, squatter book; the thin, glossy stock has been abandoned; fewer illustrations on each page abolishes the distracting busyness; much of the technical information is removed to the extensive glossary, a valuable section in its own right; the indexing is much more thorough. The texts have been revised somewhat, but the aforementioned changes are more significant.