The word "order,"in architecture, has reference to the form of column and roof used by the Greeks and Romans. There are five great classes, the Doric, Grecian, Ionic, Corinthian and Composite. During the past few centuries there has been little originality in this branch of art, each designer prefering to follow after the known systems and only introduce new combinations ; and in ages yet to come we shall not, like our ancestors, have a distinct and definite system of architecture by which to be distinguished. As iron is now entering so largely into our buildings, surely some new style ought to be adopted, as it is self-evident that that style which was easy, harmonious and graceful when built up of stone will not be the same when moulded in iron. Our architects should look to this, and see that, if iron is to characterize this age as a building material, it should carry with it its distinctive style of art.