As the object of introducing the subject here is not to write an essay on Ethnology, but to render the history of Architecture interesting and intelligible, it may be expedient to avoid all speculation as to the origin of mankind, or the mode in which the various races diverged from one another and became so markedly distinct. Stretch the history of Architecture as we will, we cannot get beyond the epoch of the Pyramid builders (3500 B.C.), and when these were erected the various races of mankind had acquired those distinctive characteristics which mark them now. Not long afterwards, when the tombs at Beni Hassan were painted (2500 B.C.), these distinctions were so marked and so well understood, that these pictures might serve for the illustration of a book on Ethnography at the present day. Nor will it be necessary in this preliminary sketch to attempt more than to point out the typical features of the four great building races of mankind. The Turanian, the Semitic, the Celtic, and the Aryan. Even with regard to these, all that will be necessary will be to point out the typical characteristics without even attempting to define too accurately their boundaries, and leaving the minuter gradations to be developed in the sequel. The one great fact which it is essential to insist on here is, that if we do not take into account its connexion with Ethnography, the History of Architecture is a mere dry, hard recapitulation of uninteresting facts and terms; but when its relation to the world’s history is understood,—when we read in their buildings the feelings and aspirations of the people who erected them, and above all through their arts we can trace their relationship to, and their descent from one another, the study becomes one of the most interesting, as well as one of the most useful which can be presented to an inquiring mind. II.—TURANIAN. The result of recent researches has enabled the ethnographer to divide and arrange prehistoric man into three great groups or periods, which in Europe at least seem to have succeeded to one another; though at what time has not yet been determined even approximately; nor is it known how long any of the three subsisted before it was superseded by the next, nor how far the one overlapped the other, or indeed, whether, as was almost certainly the case, at some time all three may not have subsisted together. The first is called the Stone age, from the rude race who then peopled Europe having no knowledge of the use of metals. All the cutting parts of their implements were formed of flint or other hard stones, probably fitted with wooden or bone handles, and used as tools of these materials. These were succeeded by a people having a knowledge of the use of copper and tin, with the possession of gold, and perhaps silver. Their principal weapons and tools were formed of a compound of the two first-named metals; and their age has consequently been called the age of Bronze.