such speculations. Its jam1)s are perpendicular, its angles rigidly- rectangular, its surfaces smooth, and it is altogether as unlike the style that succeeded it as can well be conceived. We seem, therefore, forced to the conclusion that the sloping jambs of Inca architecture are only a natural expedient for shortening the length of the lintel, and their polygonal masonry probably arose from the surfaces of cleavage or fracture, into which certain kinds of stones naturally split.
Although, therefore, we are unable, with our present knowledge, to trace the external relation of the Peruvians to the other races of the American continent, there can be no doubt that when her archi- tectural remains are properly investigated, we shall understand her history, and be able to assign to her civilization its proper rank, as compared with that of other nations. Eventually, also, we need not despair of being able to determine whether the gentle subjects of the Incas belonged to the Polynesian, or to which other of the great families of mankind.
When, indeed, we look back on the progress that has been achieved in the last few years, it seems difficult to assign a limit to the extent to which architecture may be en ployed in investigations of this sort. It was not, of course, even possible to rise to the con- ception of such a scheme for tracing the affinities of mankind, till the greater part of the world had been explored, and a sufficient amount of knowledge attained to render it certain that no such exceptions existed as would invalidate the general conclusions arrived at. Now, however, that this has been done, and that we are enabled to survey and to group the whole, it may safely be asserted that the great stone book on which men of all countries and all ages have engraved their thoughts, and to which they have committed their highest aspirations, is, of all those of its class now open to us, the most attractive, and for some purposes the most instructive. No one who has followed the inquiry can well doubt that in a few years more architectural ethnology will take its proper rank as one of the most important adjuncts to all inquiries into the affinities and development of the various families of mankind.
