Donald Hill 
A History of Engineering in Classical and Medieval Times [PDF ebook] 

It is impossible to understand the cultures and achievements of the Greeks, Romans, Byzantines, and Arabs, without knowing something of their technology. Rome, for example, made advances in many areas which were subsequently lost and not regained for more than a millenium. This is a knowledgeable yet lucid account of the wonderful triumphs and the limitations of ancient and medieval engineering. This book systematically describes what is known about the evolution of irrigation works, dams, bridges, roads, building construction, water and wind power, automata, and clocks, with references to the social, geographical, and intellectual context.