74 



A MANUAL FOR NORTHERN WOODSMEN 



revolved on its axis; (3) the axis of the telescope bubble 

 to be parallel to the line of sight, thus enabling the instru- 

 ment to be used as a level ; (4) the vernier on the vertical 



THE TRANSIT 



circle to be so adjusted as to give the true altitude of the 

 line of sight. These results may be secured as follows: 

 a. To adjust the plate levels so that each is in a plane 



