The Art of Carpentry is one of the leading parts of the sciences of architecture and engineering. It has claimed and received the attention of the masters in those sciences, and must always be a subject worthy of scientific consideration. No unimportant portion of the writings of Delorme, Palladio, and even Vitruvius, js that which relates to the art under consideration. The frame of a building sustains the same relation to the whole edifice that the bones of the system do to the human body.

It is a self-evident truth, therefore, that a knowledge of carpentry, as a science, is of great importance to the builder; for no edifice can be properly constructed but in accordance with those rules and principles to which the art is subject. Walls of stone or brick may not for their construction demand this information; still, to all buildings there must be roofs, floors, and partitions, to construct which the art of carpentry will be employed.

The first and most important thing to be considered, in making or executing any design, is the end to be attained. If a roof is to be produced, it is not enough to know the span and the pitch, but it is quite as essential to know the material with which it is to be covered; the design best adapted for the purpose; whether the determined inclination is best for that particular covering, etc. If a floor is to be built, the carpenter is to consider the purpose for which it will generally, or may possibly, be used; if a partition is to be erected, what support it may have or may lack below, what weight may rest upon it, and to what side-strains it may be subjected.

It is, however, unnecessary to enumerate, since it is plain, that, before commencing any work, it is important to see the end as well as the beginning.

The next consideration is so to select both materials and design as to make the best possible use of the means employed. This can be done effectually only by the application of such rules as investigations have proved of value. A knowledge of the nature and properties of the kind of timber used, its strength and durability, the strains to which it will be subjected, and many other things of like nature, are of much moment in the successful practice of the art. It was a wise remark of Sir Thomas Seppings, that "the strength of a piece of framing, whatever may be the design, can never exceed that of its- weakest parts; and a partial strength produces general weakness."

The third consideration is in regard to construction itself. This science, like all others in which are involved mechanical principles, has many parts, each of which is closely interwoven with the others. Most authors have divided the art into two parts. One is called mechanical carpentry, and treats of the nature and properties of timber; the other, practical carpentry, or the use of timber. The division is, to a good degree, warranted: yet they are mutually dependent; and, in order to make a knowledge of one useful, it is necessary to understand both.

Having determined the things suggested, and, in addition, such incidentals as may be connected with them, the next step is to execute the work. Theory must now give place to practice; and what exists but on paper, or in the imagination of the artificer, is to be produced as a thing of life. To one who has thoroughly informed himself on the principles involved in the work he is to do, this part of his labor will not be without a corresponding degree of satisfaction and entertainment: for to execute a design is, or may be, as inspiring as it was to conceive and project it; and it is a question of some nicety to determine, whether the architect and the engineer experience more real pleasure in witnessing a design as it is wrought out and produced, than the mechanic, who, by care and labor, gives to comparatively crude and unfashioned materials condition and form which endow them with a power "That flings control Over the eye, breast, brain, and soul; Chaining our senses to the stone, Till we become As fixed and dumb As the cold form we look upon."

There are many things essential for the attainment of the desired end; but the most important of them all, and, in fact, the great and governing principle involved throughout, is, that the workman understand well every part of his work, and that he be possessed of a desire to excel in his profession. In this, as in all arts, "knowledge is power." The advice of Mr. Tredgold is apt, and to the point. He says, "Nothing will assist the artist more in forming a good design than just conceptions of the objects to be attained; and nothing will render those objects more familiar to the mind than drawing them."

To make enlarged copies of the designs published, and at the same time to study with care the rules which govern them and the principles that are involved, will insure success to any one who may be disposed to make the attempt.