On Measuring grcming Timber. 



265 



hf Socket of iron or brass, with a screw cut 



on the inside, for infixing a rod of any 



length required. 



Fig. 38. shows a horizontal view of the 



gauge, on which the scale arm {a a) is divided 



on its under side for the quarter girts ; also 



the tangent arms {b and c) are shown at full 



length, and the sheaves {d andy ), over which 



the cords are drawn; also a cross spring {i i) at the neck 

 of the movable tangent arm, to keep it steady and erect ; and a 

 screw {k) for fastening the arms of the gauge either square or at 

 any angular position required. 



Fig. 39. shows a different horizontal view of some of the 

 parts as above described. 



