How to Observe in Archaeology by Various
page 21 of 132 (15%)
page 21 of 132 (15%)
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2. Pacing and compass. This covers large spaces quickly, but the compass is less accurate than the pace. 3. Tape. Lines of taping must be well planned, with triangle ties to secure the angles. Pulling up straight is difficult in a wind, especially on broken ground, and one per cent. error is quite possible then. When working alone peg the tape down by the ring, or round a stone. 4. Tapes and cross lines. Stretch two strings crossing squarely on the ground: fix the square by laying a squared drawing block below and looking at strings over it. Two helpers each hold a tape, zero on a string, and the two tapes are held together by the observer and read off, giving the distance to each string; this is to be plotted at once on squared paper, and the plan is completed in detail as it progresses, without any note- book or later plotting. The helpers must be capable of holding the tape square to the string. Good for sites up to two hundred or three hundred feet. 5. Plane table. Excellent for some ground, where objects are visible from a distance: otherwise it requires a marker put up at every point to be fixed. Cumbrous to carry, much slower than 4. 6. Box sextant, used as giving angular accuracy to any of the foregoing; most useful with taping, and in following. |
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