Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Very useful magnetic data book

This book gives a huge amount of magnetic properties data (saturation field density, permeability, magnetisation etc) for metals such as Iron and nickel, but more importantly, a vast magnetic data for a wide range of Fe-Ni alloys and Fe-Co-Ni. Also it shows the effect of heat treatment and mechanical work on these properties.If I recall right, this book first published in 1951.