Step A consists in properly planing up a straight-grained block of white pine 1½ inches thick, 2 inches wide, and 9 inches long, with its sides and ends straight and true, for
The Propeller Blank. Draw a line around the four faces of this block at the exact center of the length. Then on faces C and D, lay off a distance of ½ inch on the center-line, measuring from the edge of face B, for the thickness of the propeller-hub, and draw diagonal lines from the upper and lower left-hand corners of faces C and D to the end of the hub center-line (Step B). Then cut away the portions outside of these lines, as shown in Step C. Lay out the hub upon faces A and B of the block, with a ½-inch diameter, and bore a small hole through the center to receive the propeller-shaft (Step C). Draw diagonals from the corners to the center-line of the hub (Step D); then cut away the wood outside of these lines (Step E).
The next step (F) consists in laying out the form of the propeller blade upon all four sides and ends of the block, and Step G is the final one of cutting out the propeller, scooping out its blades concave on one side, and carving them convex on the opposite side. A very sharp knife must be used for cutting; and the work must be done slowly and carefully, because the least slip is likely to ruin the propeller. The entering-edge of each blade is the almost straight edge, and should be cut very thin. The ends of the blades should also be cut thin, while the hub should be cut away as much as can safely be done without weakening the propeller.
