78. This form gave great satisfaction. A groove was cut in
the side of one of the pins to receive the 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.
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 hoard by making 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 held in place by driving in nails about it, as illustrated in
Fig.
Pages:
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73