TABLES TO FACILITATE LOCATION OF THE CUBIC PARABOLA. 28 



It has occurred to us that the ceremony witnessed by Mr. D. 

 Collins in 1795 2 was the Kudsha, because he makes no mention 

 of the large circles raised upon the ground, nor is any reference 

 made to the conspicuously marked trees always used at the Bunan 

 ceremony. Many of the particulars given by Mr. Collins corres- 

 pond with our statements, but it would appear that he was not 

 permitted to see the more sacred portions of the rite. 



TABLES to FACILITATE the LOCATION of the 

 CUBIC PARABOLA. 



By C. J. Merfield, f.r.a s. 



[Read before the Royal Society of N. S. Wales, December 5, 1900.'] 



Introduction. — In a note, 2 read before the Engineering Section 

 of this Society, the writer demonstrated a simple method of apply- 

 ing the cubic parabola, as a transition to connect the straights 

 with the circular curves of railway lines; three tables are appended 

 that are applicable to any radius. When it is desirable to apply 

 a transition, and tables are not available, some difficulty presents 

 itself to the engineer, this difficulty the appended table is designed 

 to overcome. 



The Railway Departments of this State adopt usually four chain 

 transitions to all circular curves of radius twenty chains and less; 

 tables 3 to facilitate the field operations in these cases have been 

 published by the writer in the Journal of this Society. Adopting 

 a fixed length for the transition has certain practical advantages, 

 but circumstances occur when such practice becomes inconvenient. 

 In other cases it would certainly be advantageous to eliminate 



1 Account of the English Colony in New South Wales, (London, 1798) 

 Vol. i., pp. 563 - 583, plates i. - viii. 



a Vol. xxxi., p. lvi. 3 Vol. xxix., p. 51. 



