ELISHA MITCHELL SCIENTIFIC SOCIETY. II_ 



Z Q 20 X 200 a 



100 D° 100 



Q = ^ D° = .2 XXF, 

 Q FX^- 5Q ^Q .2 XXF 



D^ 100 Z 20 X D= 



In these formulas, 



c = chord length between consecutive stations; 



^X cX 



X = , y = , are the co-ordinates of stations cor- 



100 100 



responding; 



J := length of curve from S to station X. 

 When c = 100, x = X and y = X. 



TO LAY OFF THE TRANSITION CURVE. 



I. By offsets from tJie tangent, 



c 



Example. Let <: = 20, X^ =^ 8 . \ j = Y = i Y, 



100 

 c 



x = X = i X; where Y and X, for X"" = i, 2, 3, 



100 



. . . , 8, are to be taken from the general table. 



. •. r, = -i- (100) = 20, y^ = \ (200) = 40, >'3 = i (299-99) 



= 60, etc. ; 



X, = \ (.06) = .01, x^ = I (.47) = .09, .r, = i (1.57) = 



.31, etc. 



