Salvadori clearly explains, with the invaluable aid of lots of little pictures, how and why buildings stand up. There are chapters on cathedrals, the Eiffel Tower, the Hagia Sophia, bridges, domes, and so forth. The chapter on wind is particularly fascinating--I found out a lot of things I'd had no idea of. Other chapters, like "Form-Resistant Structures," were pretty deadly dull. Overall, though, the book was well worth reading. It's not always entertaining, but it's always informative, and sometimes tremendously interesting.