Proceedings and List of Papers read. 



273 



VII. " The Conductivity of Heat Insulators." By C. G. Lamb and 

 W. G. WILSON. Communicated by Professor EwiNG, 

 F.E.S. 



VIII. " On Simultaneous Partial Differential Equations and Systems 

 of Pfaffians." By A. C. Dixon. Communicated by Dr. 

 J. W. L. Glaisher, F.E.S. 



IX. "On the Comparative Efficiency as Condensation Nuclei of 

 Positively and Negatively charged Ions." By C. T. E. 

 Wilson. Communicated by the Meteorological Council. 



X. "Data for the Problem of Evolution in Man. II. A First 

 Study of the Inheritance of Longevity and the Selective 

 Death-rate in Man." By Miss Mary Beeton and Professor 

 Karl Pearson, F.E.S. 



XL " Collimator Magnets and the Determination of the Earth's 

 Horizontal Magnetic Force." By Dr. C. Chree, F.E.S. 



XII. " On the Resistance to Torsion of certain Forms of Shafting, 

 with special Eeference to the Effect of Keyways." By 

 L. N. G. Filox. Communicated by Professor M. J. M. 

 Hill, F.E.S. 



XIII. "On the Waters of the Salt Lake of Urmi." By E. T. 



Guxther and J. J. Maxley. Communicated by Sir John 

 Murray, K.C.B, F.E.S. 



XIV. " On the Application of Fourier's Double Integrals to Optical 



Problems." By Charles Godfrey. Communicated by 

 Professor J. J. Thomson, F.E.S. 



XV. " On Diselectrification produced by Magnetism. Preliminary 

 Note." By C. E. S. Phillips. Communicated by Sir 

 William Crookes, F.E.S. 



XVI. " On the Orbit of the Part of the Leonid Stream which the 

 Earth encountered on 1898, November 15." By Dr. A. A. 

 Eambaut. Communicated by Dr. G. J. Stoxey, F.E.S. 



XVII. " On the Numerical Computation of the Functions G («), 

 Gi(£), and J n (x Ji) ; and on the Eoots of the Equation 

 K n (x) = 0." By W. Steadman Aldis. Communicated by 

 Professor J. J. Thomsox, F.E.S. 



XVIII. "Eesearches in Absolute Mercurial Thermometry." By (the 

 late) S. A. Sworx. Communicated by Professor H. B. 

 Dixox, F.E.S. 



The Society adjourned over the Long Vacation to Thursday, 

 November 16, 1899. 



