'2'88 APfARATUa FOIl R.USING BODIES UNDER >VATEK. 



from the shore as to render a boat necessary for us to reach 

 the spot. T!ie ch'pth of the water wus ten feet, and we 

 -found a difficulty, from the buoj^ancy of the pole in Dr. 

 Cogan's drag, in forcins> it to the bottom ; and when we did, 

 the stones, or wliatever it met with, so favoured its buoy- 

 ■ancv,-as to toss it up coni-idcrably when drawing forwards, 

 and it required t-l^e force of both hands to keep it down so 

 as to scrape the bottom with it. The result was, that the 

 force the person holding the drag was obliged to useto 

 counteract the buoyancy of its pole (added to the weight 

 and resistance of the water against it) overpowered the 

 jneans of the person v/ho ha 1 the guidance of the bout, to 

 move it in the direction he wished ; and instead of the move- 

 ment or the boat directing the drag (or rather the person 

 liolding it) the d' ag, by the force required to keep it at^'the 

 bottom, and by the weight and resistance of the water act- 

 ing on its pole, governed the boat, and was as it were an 

 I anchor td it, confining the efforts of the person standing in 



it and using the drag, and unking the action of the drag 

 stationary instead of progressive. 



, The extreme scope of this drag not exceeding eighteen 

 inches, may it not require too much time to traverse the un- 

 . , .certain space wherein the object to be searched for lies, 

 rncinveiiience.to insure its success ? The bar drag, of which Dr. Hawes 

 efthe bar drag. ^^^^ ^^ j|^^ sketch, in point of extent and its consequent 

 ■expedition uiight answer where, the bottom is level, and tio 

 lidges or hollows would occur; but, as being a straight piece 

 of wood, it can accommodate itself to no unevennesses, coa- 

 .sequently must leave holes, the mcst likely repository of th^ 

 object sought for, imsearched. . 



Spot where a' One v'anuot but be aware, that it will seldom happen, that 

 body lies un- ||jg precise spot can be ascertained. Either from the current 

 of the water, the confusion or difference of opinion among 

 spectators, the space to be searched is generally considerabh 

 and uncertain. Adverting, therefore, to what Dr. Hawi 

 ■had sent me, and to the conversation I had with him, 

 well as the inquiries 1 had made, I thought something ■ 

 DesideratLim, gtill wanting ; and the desideratum appeared to me to be 

 ■machine that would be expeditious, because it was exten- 

 sive ; and secure, because by accommodating itself to 



ground. 



