[Illustration: Figure 5.--Caliper Rule. A handy slide caliper shop rule is made with a slide marked in fractions of inches as shown in the drawing. The diameter of a rivet, bolt or other round object may be taken instantly. It is not so accurate as calipers for close measurements, but it is a practical tool for farm use.] The handiest measuring tool ever invented is the old-fashioned two-foot rule that folds up to six inches in length to be carried in the pocket. Such rules to be serviceable should be brass bound. The interior marking should be notched to sixteenths. The outside marking may be laid out in eighths. The finer marking on the inside is protected by keeping the rule folded together when not in use. The coarser marking outside does not suffer so much from wear. Figure 5 shows a 12-inch rule with a slide caliper jaw. [Illustration: Figure 6.--Small Pocket Oilstone. Shop oilstone in a box. 100-foot measuring tapeline marked in inches, feet and rods.] In using a two-foot rule to lay off work the forward end should contain the small figures so that the workman is counting back on the rule but forward on the work, and he has the end of the rule to scribe from. In laying off a 16-foot pole the stick is first marked with a knife point, or sharp scratchawl, and try square to square one end. The work is then laid off from left to right, starting from the left hand edge of the square mark or first mark. The two-foot rule is laid flat on top of the piece of wood. At the front end of the rule the wood is marked with a sharp scratchawl or the point of a knife blade by pressing the point against the end of the rule at the time of marking. In moving the rule forward the left end is placed exactly over the left edge of the mark, so the new measurement begins at the exact point where the other left off, and so on the whole length of the stick. The final mark is then made exactly sixteen feet from the first mark. In sawing the ends the saw kerf is cut from the waste ends of the stick. The saw cuts to the mark but does not cut it out. In using a rule carelessly a workman may gain one-sixteenth of an inch every time he moves the rule, which would mean half of an inch in laying off a 16-foot pole, which would ruin it for carpenter work. If the pole is afterwards used for staking fence posts, he would gain one-half inch at each post, or a foot for every twenty-four posts, a distance to bother considerably in estimating acres. It is just as easy to measure exactly as it is to measure a little more or a little less, and it marks the difference between right and wrong. WOODWORKING BENCH In a farm workshop it is better to separate the woodworking department as far as possible from the blacksmith shop. Working wood accumulates a great deal of litter, shavings, blocks, and kindling wood, which are in the way in the blacksmith shop, and a spark from the anvil might set the shavings afire.