Amelie von Zumbusch 
Ancient Roman Technology [PDF ebook] 

To this day, the Romans are admired for their technological know-how and massive, well-designed public works projects. Readers learn how the Romans ensured a clean water supply for their cities, used volcanic ash to make long-lasting concrete, created the world’s first professional army, and much more. Photographs of structures that are standing to this day help demonstrate the ingenuity of Roman engineers and the skill of Roman workers.