So long as the geographer confines himself to mapping out the different countries of the world, or smaller portions of the earth’s surface, he finds no difficulty in making a projection which shall correctly represent the exact relative position of all the various features of the land or sea. But when he attempts to portray a continent, some distortion necessarily results; and when he undertakes a hemisphere, both distortion and exaggeration become inevitable. It has consequently been found necessary to resort to some conventional means of portraying the larger surfaces of the globe. These avowedly do not represent correctly the forms of the countries portrayed, but they enable the geographer to ascertain what their distances or relative positions are by the application of certain rules and formulæ of no great complexity. The same thing is true of history. So long as the narrative is confined to individual countries or provinces, it may be perfectly consecutive and uninterrupted; but when two or three nations are grouped together, frequent interruptions and recapitulations become necessary; and when universal history is attempted, it seems impossible to arrange the narrative so as to prevent these from assuming very considerable importance. The utmost that can be done is to devise some scheme which shall prevent the repetition from leading to tediousness, and enable the student to follow the thread of any portion of the narrative without confusion or the assumption of any special previous knowledge on his part. Bearing these difficulties in mind, it will probably be found convenient to divide the whole history of Architecture into four great divisions or parts. The first, which may be called “Ancient or Heathen Art,” to comprehend all those styles which prevailed in the old world from the dawn of history in Egypt till the disruption of the Roman Empire by the removal of the capital from Rome to Constantinople in the 4th century.