A European consensus of taste had been achieved by the late seventeenth century, despite the division of Europe into Catholic and Protestant countries, and this consensus was maintained, and even grew in strength, for another hundred years and more. When it finally broke down in the second quarter of the nineteenth century, it necessarily broke down in different ways and to a different degree in each country. No new cultural synthesis was achieved, at least as regards architecture, before our own day. The resultant stylistic patchwork that the second half of the nineteenth century inherited was largely the product of the increasing nationalism of the two decades that preceded the mid century. This particularistic nationalism, rather than the concurrent increase in mere eclecticism of taste—for such eclecticism had existed to a greater or lesser degree since the mid eighteenth century—explains the major difference in the architectural climate around 1850 from that around 1800; at least it is some part of the explanation. To be Roman in architecture, to be Greek, even to be Italian, one need not cease to be English or French or German. But to be Tudor one must be English, as to be _François I_ one must be French, or so it seemed to most architects and their clients in the forties. From this pattern of growing nationalistic divergence, this Late Romantic disintegration of the cultural unity that had remained strong and vital through the first few decades of the century, it is important now to turn to an aspect of architecture that derived from a different international absolute, that of science and technology. The English led in most technological developments affecting building methods from the mid eighteenth century on, both in the introduction of new materials and in the exploitation of new types of construction to serve new needs. But they led only because the Industrial Revolution, at once the result of certain major technological changes and the cause of innumerable others, had its origins and its early flowering in England. Before the first half of the nineteenth century was over, other countries to which the Industrial Revolution came relatively late were rapidly catching up. After the fifties technological leadership in building passed from Britain to the United States and to the Continent. Some consideration of the increased use of iron and glass between 1790 and 1855 may well conclude the first part of this book. ------------------------------------------------------------------------ CHAPTER 7 BUILDING WITH IRON AND GLASS: 1790-1855