The professions of architect and engineer, which had maintained very close links since the time of the Renaissance, became increasingly isolated from one another in France during the course of the eighteenth century, the 'Age of the Enlightenment'. This book analyses the meaning of this gradual mutual isolation, the consequences of which can still be felt at a variety of different levels, and offers a unique insight in English to the teaching and practice of architects such as Jacques-Francois Blondel and Pierre Patte, and engineers such as Jean-Rodolphe Perronet and Gaspard-Riche de Prony. The text of the book is clear and easily comprehensible, and presents a fully accessible account of this key period in the development of architectural achievement and debate.