to half-and-half solutions. The reason is that the various objects have not been standardized. As the necessary state of mind does not exist, attention has never been given to the serious study of the various units, and still less to that of the construction itself; the mass-production state of mind is hateful to architects and to the ordinary man (by infection and persuasion).
The prime consequences of the industrial evolution in "building" show themselves in this first stage; the replacing of natural materials by artificial ones, of heterogeneous and doubtful materials by homogeneous and artificial ones (tried and proved in the laboratory) and by products of fixed composition. Natural materials, which are infinitely variable in composition, must be replaced by fixed ones.
On the other hand the laws of Economics demand their rights: steel girders and, more recently, reinforced concrete, are pure manifestations of calculation, using the material of which they are composed in its entirety and absolutely exactly; whereas in the old-world timber beam there may be lurking some treacherous knot, and the very way in which it is squared up means a heavy loss in material.
Lastly, in certain fields, the technical experts have already spoken. Water supply and lighting services are rapidly being evolved; central heating has begun to take into consideration the structure of walls and windows—surfaces which tend to cooling, for instance—and in consequence stone, the good old material stone, used for walls 3 feet thick or more, is seen to be more than outmatched by light cavity walls in breeze slabs,
