Fig. 78. Forming the Links. form consisted of a 1-inch board in which two 1/2 inch holes were drilled, just 11-1/2 inches apart, measured from their centers. An oak pin, 1/2 inch in diameter, was driven into each hole and projected about an inch above the board. Two blocks of oak were secured to the baseboard, just before each pin, as shown in Fig. 78. This form gave great satisfaction. A groove was cut in the side of one of the pins to receive the
Fig. 79. A Double-Ringed Link. ring of a completed link, while the wire was passed through this ring and bent around the peg to form the ring of the new link. After each link was formed it was carefully measured, and, if too long, was shortened by flattening the rings endwise, or, if too short, was lengthened by pinching together the sides of the rings. There were fifty links in our chain, and every tenth one was formed with a double ring at the end, so as to distinguish it from the rest (see Fig. 79).
The Surveyor’s Rod.
Fig. 80. Cutting Out a Disk.
We completed our outfit by making a surveyor’s rod out of a straight stick of wood about 6 feet long. A target or sighting disk was mounted on the stick. This disk was 6 inches in diameter, and was sawed out of a 6-inch square board by making
Fig. 81. The Sighting Disk straight cuts across the corners and then smoothing off the edge to a perfect circle with a draw-knife. The thickness of the disk was only 1/2 inch. At the back of the disk we fastened a block of wood with a slot cut in it to receive the rod, as shown in Fig. 81. To hold the disk at different heights on the rod a small bolt was used. The nut on this bolt was slipped into a hole on the block at the bottom of the slot and