Fig. 235. A packing case
As a good example of estimation, take the hexagonal tabourette shown in [Fig. 178]; the five pieces, aside from the hexagon under and supporting the top, which may be made from scrap lumber, are shown laid out in [Fig. 236]. The board must be at least twelve inches wide in order to get out of it the large hexagon. The legs may be laid out as shown with space left between for sawing, yet even by this method considerable waste will result, and it should be kept constantly in mind that as far as possible waste is to be reduced to a minimum. "Wood butcher" is the common shop name for the workman who spoils more material than he uses.
The great advantage of making out a bill of material before starting is that it not only makes you study your drawing, but causes you to consider the best method of laying out the blank pieces.
Fig. 236. Laying out the pieces for a tabourette
It is often necessary to find the areas of figures other than the square or parallelogram. Assume that we are to floor a room in an octagonal tower or summer house. If the distance across the flat sides of the octagon is sixteen feet, leaving out the item of waste, how many square feet will be required?
Fig. 237. Finding the area of an octagon