114 Report of the Board of Shell Fish Commissioners 



During the progress of the launch over an oyster ground the 

 leadsman, occupying a cage attached to th? roof on the star- 

 board side, forward, throws his lead line at intervals of 15-20 

 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, sticky, hard or grassy. 

 < The recorder, seated in the after part of the launch with a 

 clock before him, notifies the leadsman at the end of each 15-20 

 second interval, by means of an electric bell, when it is time 

 for soundings to be made, and in a sounding record book 

 records the findings of the leadsman in the following symbols : 

 S (soft), St. (sticky), H (hard), G (grassy). 



The local assistant, operating the chain apparatus (see fron- 

 tispiece) from the forward port side of the launch, tests the 

 oyster ground at the end of each 15-20 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 recorded in the sounding record book with the initial 

 letters of the terms used to describe the condition of the 

 ground. 



The chain apparatus 38 as it appears in operation is shown in 

 the frontispiece of this report. 



It consists in a drag made up of three pieces of chain 

 fastened to the middle and ends of a wooden bar two feet in 

 lengtti, to which by means of a short wire bridle a stout copper 

 wire is attached. To this' wire, near the point where it passes 

 to a reel on the launch, a short slender wire is joined, by means 

 of a hook, which leads to a resonanter fastened to the roof of 

 the launch. When running a line of soundings the drag at 

 the end of the stout wire is towed over the bottom, and from 

 the vibrations or lack of vibrations on the wire the condition 

 of the ground is inferred. The vibrations are detected by the 

 . hum of the resonanter or by holding the wire in the hand. 



the form as use'd until recently the drag on the chain apparatus 

 consisted of but a single piece of chain and there was no resonator 

 attached. 



