Every workman must be aware of the meaning of the terms dove-tail, mortice and tenon, grooving, etc, but the best methods of performing these several operations of joining their work together, they only get by experience, and are not in general aware of the proportions that one piece should be which is fitted into another, so as to produce the greatest strength with the least waste of material, or so to proportion their joints, that one part shall not be liable to fail or give way before another: we shall here therefore endeavour to lay down some rules, and produce some examples that will be an attempt, at least, to bring into view the principles of the mechanism of joining, the absence of which is often the cause of work not standing well, and cause the parts either to separate with a trifling strain, or from being bound too tight together, to fly and split in all directions, not so much in general from the bad execution of the work themselves, as from want of proportioning the strength to the stress of the joints; we shall therefore arrange in order the several kinds of joints or methods of framing and joining timber, and under each head give such directions, founded on the principles of mechanics, as will enable the workman to proceed with some degree of certainty, and not, as is too frequently the case with many artizans, observe no rule but that which custom has authorised, or practice made familiar.