The Compass

Paula Z. Hogan writes mostly for children- this book is rated for the 9-12 age group although people from all age groups and educational backgounds will no doubt admire the ground Hogan covers. The info is short, to the point and well researched. There are fun and simple experiments to illustrate magnetic field phenomena and good illustrations depicting the long history of the compass. I rated this book as a 5 star because it goes way beyond what one would expect from a book for children. The history of the compass is well presented and very complete with fascinating tidbits of information from ancient China to present day use. Over 2,000 years ago the Chinese discovered the magnetic qualities of lodestone, which they referred to as "tzu shih" or loving stones and they learned that metal magnetized by loadstone and balanced on a peg or floated in water, always pointed to the south. Land bearings could be established with this object. But it was possibly the Phoenecians who first used this discovery as an aid to ship navigation and using the north heading. Eventually and over many centuries, the compass reached Greece,Italy and then England and it was here that the compass was not only perfected, but also, the phenomenon of magnetism and why it works was discovered. I admire Hogan for packing so much relevant info into a compact format!