dumpy tuesday

Today we spent familiarizing ourselves with the dumpy, using it to plot rise and fall and to measure distance. In the morning, in teams we plotted the rise and fall of the perimiter of the TAFE campus using the dumpy. After completing the circut we were only 45mm out over a 900m course so we were reasonably happy with that. We then plotted our results on a chart that included a line graph and the rise and fall of each 60m segment of the perimiter.

After lunch we focused on using the dumpy to measure distance. This can be done by positioning the dumpy over a mark (using a plumb bob for accuracy) and the staff at the point to which we plan to measure the distance. We then take the measurement on the staff between the top and bottom stradia marks and every centimetre equals 1m. Using the dumpy, the distance between the points we measured was 56m, we then double checked with a long tame and the distance was 55.8m.

Tommorrow we are going to take a look at setting out