Freeman and Lourca present an overview of technological progress, a process they describe through Kondratiev Waves, repeating cycles of economic development based on some fundamental technology and its offshoots. From water power and iron in Britain, to the modern computer revolution, these fundamental technologies have drastically reshaped economies. "As Time Goes By" explores five Kondratiev Waves, as well as the history of cliometric. While a little dated, this is still an essential book for anyone interested in the history of innovation.