The letter from which I have made a quotation at page 42, arose out of the following circumstance:—In order that my theory, as applied to the orthographic beauty of the Parthenon, might be brought before the highest tribunal which this country afforded, I sent a paper upon the subject, accompanied by ample illustrations, to the Royal Institute of British Architects, and it was read at a meeting of that learned body on the 7th of February 1853; at the conclusion of which, Mr Penrose kindly undertook to examine my theoretical views, in connexion with the measurements he had taken of that beautiful structure by order of the Dilettanti Society, and report upon the subject to the Royal Institute. This report was published by Mr Penrose, vol. xi., No. 539 of _The Builder_, and the letter from which I have quoted appeared in No. 542 of the same journal. It was as follows:— “GEOMETRICAL RELATIONS IN ARCHITECTURE. “Will you allow me, through the medium of your columns, to thank Mr Penrose for his testimony to the truth of Mr Hay’s revival of Pythagoras? The dimensions which he gives are to me the surest verification of the theory that I could have desired. The minute discrepancies form that very element of practical incertitude, both as to execution and direct measurement, which always prevails in materialising a mathematical calculation under such conditions. “It is time that the scattered computations by which architecture has been analysed—more than enough—be synthetised into those formulæ which, as Mrs Somerville tells us, ‘are emblematic of omniscience.’ The young architects of our day feel trembling beneath their feet the ground whence men are about to evoke the great and slumbering corpse of art. Sir, it is food of this kind a reviving poetry demands. ——‘Give us truths, For we are weary of the surfaces, And die of inanition.’ “I, for one, as I listen to such demonstrations, whose scope extends with every research into them, feel as if listening to those words of Pythagoras, which sowed in the mind of Greece the poetry whose manifestation in beauty has enchained the world in worship ever since its birth. And I am sure that in such a quarter, and in such thoughts, _we_ must look for the first shining of that lamp of art, which even now is prepared to burn. “I know that this all sounds rhapsodical; but I know also that until the architect becomes a poet, and not a tradesman, we may look in vain for architecture: and I know that valuable as isolated and detailed investigations are in their proper bearings, yet that such purposes and bearings are to be found in the enunciation of principles sublime as the generalities of ‘mathematical beauty.’ “AUTOCTHON.” No. III.