Abstract: A drafting table includes vertical and horizontal straight edged supports together with drive mechanisms for moving the vertical straight edge such that it will always point to a viewing point and for moving the horizontal straight edges in plural different modes. In a first mode, the two horizontal straight edges are moved such that their edges always point to respective vanishing points. In a second mode the horizontal straight edges are moved such that one continues to point to a vanishing point while the other maintains a fixed angle with respect to horizontal, and so that their edges always intersect at a point along the line of view. The drive mechanisms for the horizontal straight edge supports can be disabled, reversed or their drive ratios changed in accordance with the particular drawing being made.

Abstract: A straightedge is made of a sawable material, and is fixed relative to a saw guide, and the saw guide is provided with multiple guide surfaces so that guiding the saw along the different guide surfaces of the saw guide will cut the straightedge to form multiple cut location indicators.

Abstract: A fixed-angle saw guide is provided with a cut location indicator disposed in the path of the power saw and at a level no higher than the level of the work piece being cut. Two different variable-angle saw guides each include fixed and movable members coupled to one another via at least one slot and multiple pins such that the saw blade will pass through a common point regardless of the cutting path. A retractable cut location indicator is mounted to the fixed member.

Abstract: A first rod includes a relative elevation scale and a first fluid container vertically adjustable with respect to the relative elevation scale to a position corresponding to a desired elevation relative to the base of the first rod, and a second rod includes a second fluid container of substantially lesser cross sectional area than the first fluid container, a predetermined level of fluid in the second fluid container indicating that the base of the second rod is at a desired elevation relative to the base of the first rod.

Abstract: A direct reading grade rod as provided with a fixed scale having display windows therein and one or more sliding members slidable behind the fixed member and carrying a plurality of number sets, with different positions of the sliding member resulting in different sequences of numbers displayed in the windows.