The book was quite good, but not exactly what I expected. I expected more of a semi-technical introduction and history of sextants. What we got was a high level overview of their workings and a small history of their development. This was couched in a much larger overview of the great exploratory voyages of the 18th and 19th centuries where sextants were critical in their navigation.

And that was not bad, just not exactly what I was expecting.