502 Prof. W. J. Sollas. Report to the Committee appointed 



frequency it is seen that they coincide with the diagonal from the 

 0/0 corner; also that the entries of minimum frequency are dis- 

 posed symmetrically on either side of that diagonal and converge 

 towards the same corner. Consequently, the existence of spurious 

 correlation is manifest here. If B be the constant, and A and C the 

 variables, the general results will of course be the same. 



Secondly, let both A and B be constant and equal to I, and C the 

 only variable ; then there are only three possible combinations of A/C 

 and B/C. In one of them both values are equal to I, in another 

 to I/II, and in the third to I/III, all of which lie along the diagonal 

 from (0, 0), and thus testify to intimate correlation. 



Lastly, let C be the only constant and equal to 1. Then A/C, B/C, 

 become A and B, and the table of frequency of their various com- 

 binations is that shown in Table I and by the large figures in fig. 1, 

 whose symmetrical disposition in all directions proves that there is 

 no correlation. 



" Report to the Committee of the Royal Society appointed to 

 Investigate the Structure of a Coral Eeef by Boring.'' 

 By W. J. SOLLAS, D.Sc., F.R.S., Professor of Geology in 

 the University of Dublin. Received December 31, 1896, 

 Read February 11, 1897. 



Prefatory Note ly Professor T. G. Bonney, D.Sc., LL.D., F.R.S., 



Vice- Chairman of the Committee. 



In presenting, as desired by the Committee, Professor Sollas's report 

 on the attempts to ascertain, by boring, the structure of the atoll 

 of Funafuti and on other investigations simultaneously undertaken, 

 I avail myself of the opportunity of expressing the gratitude which 

 is felt by its members to our friends in New South Wales, who have 

 given such real and substantial help, especially by the loan of 

 machinery and skilled workmen, in putting the project into execu- 

 tion ; and among them chiefly to Professor Anderson Stuart (who has 

 been practically another secretary in Australia), Professor Edgeworth 

 David, Mr. W. H. J. Slee (Chief Inspector of Mines), and Sir Saul 

 Samuel (the Agent- General of the Colony in England). I shall 

 venture also to acknowledge gratefully the services of Captain Field 

 and the officers of H.M.S. 4< Penguin," and the unstinted labour 

 which has been given by Mr. W. W. Watts, F.G.S., our Secretary in 

 London, in carrying out our plans. In conclusion, may I express, 

 speaking for myself, my earnest hope that another attempt will be 

 made to determine the true structure of an atoll. I think, however, 

 that our experience on this occasion shows that the attempt can be 



