Report of the Board of Shell Fish Commissioners. 7d 
position that the left arm passes through the plotted position 
of signal A, the middle arm through the plotted position of 
signal B and the left arm through the plotted position of 
signal C the point in which the three arms of the protractor 
meet, the centre of the hub, is the point on the chart repre- 
pane the position of the boat when the sextant angles were 
taken. es 
All angles taken during the survey by the engineers are 
transferred to the protractor and plotted on the boat sheets 
by the chief engineer, while the assistant engineer records the 
angles in an angle record book. 
During the progress of the launch over an oyster ground 
the leadsman, occupying a cage attached to the roof on the 
starboard side, forward, throws his lead line at intervals of 
20-30 seconds, measuring the depth of water and testing the 
bottom at each cast. Having made a sounding the leadsman 
reports the depth of water, in fathoms and feet, and the 
character of the bottom in the following terms: soft, hard, 
sticky, rocky or grassy. 
The recorder, seated in the after part of the launch with a 
elock before him, notifies the leadsman at the end of each 
20-30 second interval, by means of an electric bell, that it is 
time for a sounding to be made, and in a sounding record 
book records the depth of water in fathoms and feet and 
character of the bottom in the following symbols: sft. (soft), 
stk. (sticky), hrd. (hard), rky. (rocky), or grs. (grassy). 
The local assistant, operating the chain-wire apparatus 
from the forward port side of the launch, tests the oyster 
ground at the end of each 20-30 second interval and reports 
to the recorder his findings in the following terms: Barren, 
very scattering, scattering, medium or dense. His report is 
given immediately following that of the leadsman and is re- 
corded in the sounding record book with the initial letters 
of the terms used to describe the condition of the ground. 
The chain-wire apparatus? as it appears in operation is 
shown on insert opposite page 67 of this report. 
1 Construction of drag on chain-wire apparatus is chunged according to con- 
ditions of bottom and depths. In very deep water only a single section of chain 
works satisfactorily. 
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