## Sawhorse and Square

The besaigue works to its best advantage when the timbers are lying low to the ground. It's a French thing, but like most other carpenters, those in France also elevate their work on the horse foaled of an acorn. Sawhorses for heavy oak timbers are more like benches made from a log; flattened on top, with three or four legs set into holes bored through it.

For stability and strength, the legs of a sawhorse splay out to the sides and to the ends. When making a heavy horse with augered leg holes, you can just eyeball the splay of the first leg, drive it in and then use it as a guide to bore the remaining holes with equal splay. In a light sawhorse, made from sawn stock and held with screws and nails, you work by more calculated layout. Finding these leg splay angles gives us a brief lesson in using the framing square. Don't run away.

The square is fixed at 90 degrees and marked in inches, counting out from the heel. This and an angle table are all you need to measure and mark any angle. For example, the rafter feet of a half-pitch roof must be cut at 45 degrees. To find 45 degrees across a timber, position the square on the timber's edge so that the square crosses at any equal number on both limbs.

A light sawhorse runs about four feet long and two feet high. The splayed-out, 1-by-3 legs lap into angled seats cut across the 2-by-4 top beam. Twenty-two degrees is a good endwise splay for the legs. To find 22 degrees, set the square on the top beam of the horse-to-be so that it crosses at the 8 inch mark on one limb and the 20 inch mark on the other. Draw this line across the beam of the horse and you have the end splay.

Another way to express an angle is as a ratio. When we get to dovetail angles, we'll refer to an angle of one in six—a one-inch rise over a six-inch run. On the sawhorse, the legs also need to splay out to the sides enough to make the feet sit at least 14 inches apart—or each leg seven inches out of plumb. Since the horse is to stand 24 inches high, the ratio is 7 in 24. Set a straightedge to cross the square at these respective inch marks and you have the second angle for the notch in the top beam.

Now you have the angle, but how do you transfer it to the narrow top beam of the sawhorse? Simply derive smaller units from the square instead of full inches. The 7 in 24 ratio remains the same if the units are feet, inches, eighths, or sixteenths. If the angled notch runs 7 units in on the top of the beam and 24 units down on the side, the leg fitted into it will splay accordingly.