Figure 2-16. Construction Details for a 4-Foot Stand (continued)
a. Four-foot stands are tripods that are usually built of standard commercial sizes of lumber. The 2-
inch by 4-inch legs on the low stands can often be purchased from the mill with a 60, bevel lengthwise
along one edge, or 2-inch by 6-inch legs may be ripped or cut lengthwise at a 60, angle into two boards
of an equal cross section. This helps to make a better nailing surface and a more stable stand. It is often
advantageous to draw a pattern and cut the lumber to standard size in the base camp. Four-foot stands
can often be made in advance as available men and the weather permit.
b. Dig holes for the legs of the tripod stand whenever possible. The tops of these holes should be
left open to avoid transmitting surface disturbances to the stand. The stand should be securely staked in
place.
c. Place footboards or a platform for the observer around the stand. This should be supported as far
as practicable from the legs of the instrument stand.
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