. Annual report. Entomological Society of Ontario; Insect pests; Insects. 10 REPORT OF THE ENTOMOLOGICAL. Fig. 1. Counting rate meter and Geiger probe in position to take a reading on the lid of the experimental chamber. This lid has a grid marked on it so that the position of the probe may be determined. TABLE I VARIATION IN COUNTING RATE WITH POSITION OF GEIGER PROBE PROBE POSITION Distance (in inches) horizontally from position of probe when directly over the cobalt piece COUNTS PER Co60 in fixed position under 2l/% in. of soil MINUTE Co60 in fixed position under 5 in. of soil 0 15,250 4,00
. Annual report. Entomological Society of Ontario; Insect pests; Insects. 10 REPORT OF THE ENTOMOLOGICAL. Fig. 1. Counting rate meter and Geiger probe in position to take a reading on the lid of the experimental chamber. This lid has a grid marked on it so that the position of the probe may be determined. TABLE I VARIATION IN COUNTING RATE WITH POSITION OF GEIGER PROBE PROBE POSITION Distance (in inches) horizontally from position of probe when directly over the cobalt piece COUNTS PER Co60 in fixed position under 2l/% in. of soil MINUTE Co60 in fixed position under 5 in. of soil 0 15,250 4,000 Va 15,000 3,900 Vz 14,500 3,750 Va 13,250 3,600 i 12,250 • 3,500 2 11,000 3,150 3 6,500 2,700 Before the cobalt pieces could be attached to the larvae, it was necessary to determine the effects of various depths of soil on the counting rate. A plastic cylinder 12 inches high, marked at intervals of one-quarter of an inch, was used for this purpose (Fig. 2). A sleeve made to fit over the counter had just the same diameter as the inside of the cylinder. Two metal rods held by set-screws to a metal lip on the top of the cylinder supported the counter sleeve. By this means the counter could be set at any desired Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Entomological Society of Ontario; Ontario. Dept. of Agriculture. Toronto, The Society
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectinsects, bookyear1872
