A new tradition : art in engineering -- part 1. The age of iron. Thomas Telford and the new art form -- Brunel, Stephenson, and railway forms -- Gustave Eiffel and the Crescent Bridge -- John Roebling and the Suspension Bridge -- The bridge and the tower -- part 2. The new age of steel and concrete. Jenney, Root, and the first Chicago school -- Big steel bridges from Eads to Ammann -- Robert Maillart and new forms in reinforced concrete -- Roof vaults and national styles -- The directing idea of Eugene Freyssinet -- Discipline and play : new vaults in concrete -- New towers, new bridges -- Epilogue : the idea of structure as art.