Architecture may be described as building at its best, and when we talk of the architecture of any city or countr y we mean its best, noblest, or most beautiful buildings; and we imply by the use of the word that these buildings possess merits which entitle them to rank as works of art. The architecture of the civilised world can be best understood by considering the great buildings of each important nation separately. The features, ornaments, and even forms of ancient buildings differed just as the speech, or at any rate the literature, differed. Each nation wrote in a different language, though the books may have been devoted to the same aims; and precisely in the same way each nation built in a style of its own, even if the buildings may have been similar in the purposes they had to ser ve. The division of the subject into the architecture of Egypt, Greece, Rome is therefore the most natural one to follow.