The Good: An excellent overview ancient navigational instruments. In addition to sundials, octants and compasses, Fisher covers such escoteric tools as the traverse board (used to track direction and ship speed), the weatherglass (early barometer), the kamal (arabian navigation tool) and the cross staff (predecessor to the octant).
The Bad: Very crude, hand-drawn illustrations and building plans. No photographs or contemporary illustrations of the actual instruments. Though it is clear that the author has made each of these instrument himself, the book even lacks photos of his own reconstructions. Many illustrations of critical parts are unclear and difficult to understand. The only saving grace is Fisher's excellent descriptions of the parts and the building process.
The Verdict: Though his concept, scope and research are excellent, the failure of the publisher to back Fisher up with quality illustrations, photographs, and professionally-drafted design plans prevents this from being the excellent book it could have been. While it is possible to actually build these tools, the process is more difficult that it should be due to the lack of quality plans.