CHAPTER IX.
PRINCIPLES OF JOINERY.[11] [Footnote 11: Professor Rankine's Five Principles: 1.

To cut the joints and arrange the fastenings so as to weaken the pieces of timber they connect as little as possible.
2.

To place each abutting surface in a joint as nearly as possible perpendicular to the pressure which it has to transmit.
3.

To proportion the area of each surface to the pressure which it has to bear so that the timber may be safe against injury under the heaviest load which occurs in practice, and to form and fit every pair of such surfaces accurately in order to distribute the stress uniformly.
4.

To proportion the fastenings so that they may be of equal strength with the pieces which they connect.
5.