THE PROSPECTOR'S HANDBOOK. 



not balance properly, trim either end by shaving off very 

 thin pieces until it does. Now divide the strip into twenty 

 equal parts, i.e. ten on each side of the middle, and mark 

 them 1, 2, 3, &c., so that the 1 marks may be nearest the 

 middle and the 10 marks at the ends. 



Three weights are required : 



One grain : Can be obtained by weighing out a piece of 

 thin brass wire (ends bent together) on a chemist's balance. 



One tenth grain : To obtain this, place the one-grain 

 weight on the 1 mark of 

 the wooden balance and 

 place such a smaller piece 



of wire, bent at 

 FIG. 59. the ends, on the 



10 mark on the 

 opposite side, as will cause the beam to balance properly. 



One-hundredth grain : To obtain this, place the one-tenth 

 grain weight on the 1 mark, and a piece of thread or such 

 like material on the 10 mark on the other side as will cause 

 the beam to balance properly. 



To weigh the Button of Gold or Silver. 



Place it on the 10 mark and see if 1 grain on 10 mark 

 (opposite side) exactly balances it; if it does, the button 

 weighs 1 grain. If the wire weight be too much, move it 

 towards the middle of the beam to a division, until it is a 

 little lighter than the button. Leave it on this mark. Then 

 take the one-tenth grain, and, commencing from the end of 

 the beam, move it towards the middle until the division 

 reached is that one where this weight together with the first 

 weight is just lighter than the button. Then proceed with 

 the one-hundredth grain in the same way. 



Suppose, now, that the one grain weight be at 8, the one- 

 tenth grain at 7, and the one-hundredth at 3, the weight of 



