344 Harmonic Analysis of Tidal Observations. [May 7, 



Philosophy in the University of Glasgow, who also assisted me in the 

 detemination of the rigidity modulus ; they are as follows : — 



Young's Modulus, (Pl/cce where P is the stretching weight, I the 

 length of wire used, a the cross sectional area, and e the elongation 

 produced by the pull P) 1222*4 x 10 6 grammes weight per square 

 centimetre. 



The breaking weight is about 6*029 X 10 6 grammes per square 

 centimetre. 



I have also determined the specific gravity of a specimen of platinoid 

 wire, and find it to be 8*78, compared with water at 20° C. 



Platinoid when drawn hard, is softened like copper by heating and 

 sudden cooling. 



V. " Results of the Harmonic Analysis of Tidal Observations." 

 By Major A. W. Baird, R.E., and G. H. Darwin, F.R.S., 

 Fellow of Trinity College and Phimian Professor in the 

 University of Cambridge. Received March 19, 1885. 



[Publication deferred.] 



The Society adjourned over Ascension Day to Thursday, May 21st. 



