We all know that reading is a hit-or-miss sort of phenomenon. Sometimes we pick up books that look promising, only to be disappointed as we read farther into them. Other times, we pick up books with little or no expectations and are pleasantly surprised.

And sometimes, just sometimes, we get really excited about a book and can't put it down, and have to tell everyone we know how awesome it was.

Believe it or not, The History and Practice of Ancient Astronomy by James Evans is a masterpiece of writing. It inspired me to buy an armillary sphere and an astrolabe, and I'm sure that before long I'll be spending around $1,000 on an expensive telescope. The book got me enthusiastic about science, something that...well...just doesn't happen.

It's hard to even figure out where to begin. Evans arranged his book topically. After a short introduction to the two main systems of astronomy in antiquity, the Babylonian and the Greek, he then moves in a topical fashion. He covers the concept of the celestial sphere, the calendar, solar theory, the fixed stars and finally the planets. Each chapter builds on what was discussed in the last. He therefore breaks up the works of famous authors like Aristarchus of Samos, Hipparchus and Ptolemy by topic rather than by time period.

In each chapter, the reader is encouraged to conduct backyard astronomy to replicate the observations of the ancients. In the second chapter, for example, he encourages the reader to make a homemade sundial and go out every half hour on a sunny day to plot the shadow of the gnomon. Then you draw an arc connecting the dots and can determine the angle of the sun based on the length of the gnomon. He then provides little blocks of questions which the reader can skip or try to solve as though the book were a textbook.

At times, his calculations can get a bit math-heavy, but Evans recognises this and at one point even states "Readers who are not on friendly terms with trigonometry may skip this postscript".

At the back, he has pages that can be copied and then used to produce a homemade astrolabe, complete with instructions as to how to draw the azimuths and other lines for one's own particular location.

Ultimately, what Evans has produced is a book that not just explains what the ancients knew and learned about astronomy, but a book that shows the same and encourages you, the reader, to duplicate their findings. He avoids talking about the religious implications of celestial events in the ancient world, focusing more on the science, but he also does not fail to mention why certain phenomena were important to the ancients and mediaeval writers (casting horoscopes, planning religious festivals, etc.).

As a result, what could have been a dry book about how the ancients performed astronomy turns into a fascinating book that teaches the reader how to perform ancient astronomy. It is written in a clear, witty fashion but does not talk down to the reader (and therefore cannot be called "popular science" - it is at times far too technical for that). It is an engaging and challenging book that has been an unmitigated joy to read. At 450 pages of small fonts on big paper (the pages are 8 1/2 by 11 inches, or slightly smaller than A4 for you European types) it is a big book. It has lots of charts, graphs and illustrations, though, and I've found it to be a thoroughly enjoyable read. I highly, highly, highly recommend it to people who, not being scientifically inclined, enjoy being able to get excited about science. For someone who is more scientifically inclined than myself, I can only imagine the reading experience will incite orgasms.