light upon our subject. A very different aspect, however, is presented in Egypt and in India, where monuments of the most remote antiquity remain, interesting in themselves, and as they tend to illustrate the progress and the revolutions of Architecture in its more modern forms. From an examination of the former, we shall be enabled to discover the germs of the more perfect Greek modes, while, in the combinations of Arabian with Indian forms, we seem to detect the rudiments of that singular style, which, under the various appellations of Arabic, Saracenic, Gothic, has extended over the whole of Europe, and a considerable portion of Asia. Thus, one of the first and one of the last departments of the present subject, one of its purest and one of its most complicated systems, originates probably in countries now to be considered, and whose monuments are coeval with the first reunion of intelligence and society among men. But, before entering upon the inquiry which is to trace this connexion through the history of the art, it becomes necessary to explain certain common and preliminary principles. There are three grand causes of structure and form in Architecture,--three leading principles, which not only originated the primeval elements of design, but which, to a great degree, have governed all the subsequent combinations of these. This influence also extends not merely to the essentials of stability, equilibrium, and strength, but, as will afterwards appear, has suggested the system of ornament. These master dispositions, which it thus becomes necessary to bear along with the commencement, are, first, _the purpose_--secondly, _the material_ of Architecture--and thirdly, _the climate_. The purpose for which any building was erected, or the uses which it was contemplated to serve, would necessarily determine the magnitude, and to a certain extent, the form. Again, these considerations would suggest the most appropriate means of accomplishing the requisite ends, which, once accomplished, would constitute permanent distinctions.