It is generally acknowledged that the various styles in architecture were the results of necessity, and originated in accordance with the different pursuits of the early inhabitants of the earth; and were brought by their descendants to their present state of perfection, through the propensity for imitation and desire of emulation which are found more or less among all nations. Those that followed agricultural pursuits, from being employed constantly upon the same piece of land, needed a permanent residence, and the wooden hut was the offspring of their wants; while the shepherd, who followed his flocks and was compelled to traverse large tracts of country for pasture, found the tent to be the most portable habitation; again, the man devoted to hunting and fishing - an idle and vagabond way of living - is naturally supposed to have been content with the cavern as a place of shelter. The latter is said to have been the origin of the Egyptian style; while the curved roof of Chinese structures gives a strong indication of their having had the tent for their model; and the simplicity of the original style of the Greeks (the Doric) shows quite conclusively, as is generally conceded, that its original was of wood. The pointed, or ecclesiastical style, is said to have originated in an attempt to imitate the bower, or grove of trees, in which the ancients performed their idol-worship. But it is more probably the result of repeated scientific attempts to secure real strength with apparent lightness; thus giving a graceful, aspiring effect.

17. - Orders: or styles, in architecture are numerous; and a knowledge of the peculiarities of each is important to the student in the art. An ORDER, in architecture, is composed of three principal parts, viz.: the Stylobate, the Column, and the Entablature. This appertains chiefly to the classic styles.

18. - The Stylobate: is the substructure, or basement, upon which the columns of an order are arranged. In Roman architecture - especially in the interior of an edifice - it frequently occurs that each column has a separate substructure; this is called a pedestal. If possible, the pedestal should be avoided in all cases; because it gives to the column the appearance of having been originally designed for a small building, and afterwards pieced out to make it long enough for a larger one.

19. - The Column: is composed of the base, shaft, and capital.

20. - The Entablature: above and supported by the columns, is horizontal; and is composed of the architrave, frieze, and cornice. These principal parts are again divided into various members and mouldings.

21. - The Base: of a column is so called from basis, a foundation or footing.

Interior Of St. Stephens, Paris

Interior Of St. Stephens, Paris.

22. - The Shaft: the upright part of a column standing upon the base and crowned with the capital, is from shafto, to dig - in the manner of a well, whose inside is not unlike the form of a column.

23. - The Capital: from kephale or caput, the head, is the uppermost and crowning part of the column.

24. - The Architrave: from archi, chief or principal, and trabs, a beam, is that part of the entablature which lies in immediate connection with the column.

25. - The Frieze: from fibron, a fringe or border, is that part of the entablature which is immediately above the architrave and beneath the cornice. It was called by some of the ancients zophorus, because it was usually enriched with sculptured animals.

26. - The Cornice: from corona, a crown, is the upper and projecting part of the entablature - being also the uppermost and crowning part of the whole order.

27. - The Pediment: above the entablature, is the triangular portion which is formed by the inclined edges of the roof at the end of the building. In Gothic architecture, the pediment is called a gable.

28. - The Tympanum: is the perpendicular triangular surface which is enclosed by the cornice of the pediment.

29. - The Attic: is a small order, consisting of pilasters and entablature, raised above a larger order, instead of a pediment. An attic story is the upper story, its windows being usually square.