materials may be more or less favourable; the mechanical knowledge required may be more or less profound; it is in the solution of these problems that various races have shown a greater or less degree of intellectual power; it is from the study of the architectural problems so solved that we obtain a common measure of the mind of races perfectly distinct from any other standard.
In a Gothic cathedral the truths of mechanical science are stated, not by words, but by deeds; it is knowledge, not written, but enacted.
The pyramids and temples of Egypt, the Parthenon, the ruins of Baalbec, the Duomo at Florence, the railway bridges and viaducts of the nineteenth century, are all so many chapters in the history of mechanical science, not in themselves treatises, but containing the materials of treatises. So much has been recently written on this branch of architectural study, that I shall merely allude to it here, especially in addressing an audience many of whom have the advantage of hearing every year a lecture on structure from the historian of our cathedrals. Professor Willis.
Having glanced at Architecture as part of the history of science, let us regard it for a moment as part of the history of finance. In all Architecture there is an outlay of the capital of labour, and of the capital absorbed in the cost of materials. The wealth thus permanently invested, if it be national wealth, is seldom replaced by any direct financial return. In the balance-sheet of nations it is more frequently entered as capital sunk, than as capital profitably invested.
When, therefore, we have made an estimate of the probable cost of an ancient edifice, grounded partly on the evidence of the building itself, partly on our general knowledge of the period to which it belongs, we must next consider out of what resources it was reared: did the builders invest income or capital? in the hope of profitable return, or from what other of the many motives which induce men to spend money?
Here, then, we find an architectural common measure, not only of the wealth of nations at a particular period, but also of their taste and judgment in spending that wealth.
When we survey the architecture of all time in regard to its motive, it presents to us under this aspect four principal
