ELEMENTS or CARPENTRY.
" Carpentry is the art of framing timber for the purposes of Architecture, Machinery, and, in gene ral, for all considerable structures.
It is not intended in this article to give a fa account of Carpentry as a mechanical art, or to de' scribe the various ways of executing its different -works, suited, to the variety of materials employed, the processes which must be followed for fashioning and framing them for our purposes, sad the Oa' which must be used, and the manner in which they must be handled : This would be an occupation for volumes ; and though of great importance, must be entirely omitted here. Our only aim at present will be to deduce, from the principles and laws of me chanics, and the knowledge which experience and judicious inferences from it have given us concern ing the strength of timber, in relation to the strain laid on it., such maxims of construction as will unite economy with strength and efficacy.
This object is to be attained by a knowledge, 1st, of the strength of our materials, and of the ab strain that is to be laid on them ; 2dly, of the modifications of this strain, by the place and direc tion in which it is exerted, and the changes that can be. made by a proper disposition of the parts of our structure ; and, Sdly, having disposed every piece in such a manner as to derive the utmost advantage from its relative strength, we must know how to form the joints and other connections in such a man ner as to secure the advantages derived from this disposition.
This is, evidently, a branch of mechanical science which makes Carpentry a likeral art, constitutes part of the learning of the ENPINEER, and distinguishes him from the workman. Its importance in all times and states of civil society is manifest anal great. In the present condition of these kingdoms, raised, by - the active ingenuity and energy of our countrymen, to a pitch of prosperity and influence unequalled in the history of the world, a condition which consists chiefly in the superiority of our manufactures, at tained by prodigious Multiplication of engines of every description, and for every species of labour, the Sctexce (so to term it) of Carpentry is of im mense consequence. We regret therefore exceed
ingly, that none of our celebrated artists have done honour to themselves and their country, by digesting into a body of consecutive doctrines the results of their experivace, so as to form a system from which their pupils might derive the first principles of their education. The many volumes called COMPLETE INSTRUCTORS, MANUALS, &c. take a much hum bler flight, and content themselves with instruct ing the mere workman, or sometimes give the mu ter builder a few approved forms of roofs and other framings, with the rules for drawing them on paper ; and from thence forming the working draughts which must guide the saw and the chisel of the workman. Hardly any of them offer any thing that can be cal led a principle, applicable to many particular cases, with the rules for this adaptation. We are indebted for the greatest part of our knowledge of this sub ject to the labours of literary men, chiefly foreigners, who have published in the memoirs of the learned academies dissertations on different parts of what may be termed the Science of Carpentry. It is sin gular, that the members of the Royal Society of Lon don, and even of that established and supported by the patriotism of these days for the Encouragement of the Arts, have contributed so little to the public instruction in this respect. We observe of late some beginnings of this kind, such as the last part of Ni cholson's Carpenter's and Joiner's Assistant, publish ed by J. Taylor, Holborn, 1797. And it is with pleasure that we can say, thit we were told by the editor, that this work was prompted in a great mea sure by what has been delivered in the Encyclopaedia Britannica in the articles ROOF and STRENGTH OF MATERIALS. It abounds more in important and new observations than any book of the kind that we are acquainted with. We again call on such as bate given a scientific attention to this subject, and pray that they would render a meritorious service to their country by imparting the result of their researches. The very limited nature of this work does not allow us to treat the subject in detail ; and we must con fine our observations to the fundamental and leading propositions.