Report of the Board of Shell Fish Commissioners 45 



FACTORS. 



I 



The length of the heads of a pair of tongs of course remains 

 constant, but the width to which the heads are separated 

 in making a "grab" depends upon several factors : 



1. - The height above the water at which the tongman grasps 

 the shafts of his tongs. 



2. The width to which he separates the shafts at the level 

 of his hands. 



3. The depth of water in which he is, tonging. 



4. The position on the shafts of the pin. 



The first and second of these factors has been carefully deter- 

 mined by observing the tongmen employed by the Commission at 

 work during the season and numerous tongmen at work on 

 THREE SISTERS^, TOLLEY POINT and HACKETT POINT bars. From 

 these observations it was found that the average tongman 

 usually grasps the shafts of his tongs at a point about three 

 feet above the surface of the water, and in making a grab sepa- 

 rates the shafts at the' level of his hands, about three and one- 

 half feet. 



To find the distance between the teeth of the heads of the 

 tongs, according to the above rule, in depths of water varying 

 from five to twenty -five feet, 14 the tongs were placed in a hori- 

 zontal position on a level surface and, while the shafts were 

 properly separated, careful measurements were made of the 

 distances to which the heads were thereby opened for every 

 depth of water to which the tongs were adapted. See figure 2, 

 page 43. The results of these measurements are recorded in the 

 third column in the table on page 66. In the fourth column of 

 the same table the area of a grab made with these tongs in the 

 various depths of water is given. 



There is no fixed rule for the position of the "pin" or "pivot" 

 which fastens the shafts of tongs together, but it is usually 

 placed at a point about one- fourth to one-third the length of the 

 shafts, from the heads. 



"Several years ago tongmen sometimes worked on oyster bars located 

 in water as deep as thirty feet, but on account of the great difficulty in 

 handling the heavy shafts needed there is now practically no tonging 

 done in water deeper than twenty-five feet. 





