The efforts of primitive builders, it is true, are rather of archæological than of architectural significance, yet they have this much to do with architecture, that in them are to be discovered the rudiments of the art. For by the time that man had superimposed a stone horizontally upon two vertical ones, he had hit upon the principle of construction, now variously styled “post and lintel” or “post and beam” or “trabeated,” that is to say, “beam” construction. The embryo was conceived that in the fulness of time would be developed into the trabeated design of the Egyptian temple and the column-and-entablature design of Classic architecture. From the colossal, monolithic form, still preserved, for example, in Stonehenge, there is a direct progression to the highly organised perfection of the Parthenon. It is this fact that makes the study of architecture so vitally interesting. Its evolution has proceeded, stage by stage, with the evolution of civilisation. Having its roots in necessity, it has expressed the phases of civilisation more directly and intimately than have the other Fine Arts; while the comparative durability of the materials in which it has been embodied has caused more of its records to survive. Even out of the fragments of architecture it is possible for the imagination to visualise epochs of civilisation long since buried in the past; while the memorials that have been preserved in comparative integrity stand out through the misty pages of history as object lessons of distinct illumination. * * * * * Accordingly, one purpose of this book represents an attempt to study the evolution of architecture in relation to the phases of civilisation that it immediately embodied; to find in the monuments of architecture so many “sermons in stone”--discourses upon the character, conditions of life, the methods and the ideals of the men who reared and shaped them.