1920] 



New Method for Laying Out Circular Curves 



43 



Values of 0^, 0.,, 0.,, etc., computed by means of the above for- 

 mulas for different values of A show that they change uniformhj 

 with A ; so that interpolation gives results as closely as 1 minute for 

 ranges of 1° in A. 



PT/B 



IP 



Fig. 1 



For convenience in laying out curves without resetting the vernier, 

 these directions to points on the curve are referred to the first tangent, 

 the line CA produced. 



Instrument at the P. I., and vernier reading A° on the P. T., 

 we have : 



