IV CONTENTS OF VOL. XLII. FIFTH SERIES. 



Page 

 Dr. A. P. Pavlow on the Classification of the Strata 



between the Kimeridgian and the Aptian 120 



Mr. Beeby Thompson on the Junction-Beds of the Upper 



Lias and Inferior Oolite in Northamptonshire 121 



Mr. J. H. Cooke on the Stratigraphy and Palaeontology 



of the Globigerina-limestones of the Maltese Islands. . 122 

 Miss M. Cro>field and Miss E. G. Skeat on the Geology 



of the Neighbourhood of Carmarthen 122 



On a Eotational Motion of the Kathode Disk in the Crookes 

 Tube, by Francis E. Nipher 123 



NUMBER CCLV.— AUGUST. 



Mr. W. Williams on the Convergence of Eourier's Series . . 125 



Mr. Eollo Appleyard on Dielectrics 148 



Mr. A. Campbell on New Instruments for the Direct Measure- 

 ment of the Frequency of Alternating or Pulsating Electric 



Currents 159 



Dr. S. P. Thompson on some Experiments with Rbntgen's 



Eays 162 



Lord Eayleigh on the Theory of Optical Images, with special 



reference to the Microscope 167 



Dr. G. A. Miller on the Operation Groups of order Sp, p 



being any prime number 195 



Mr. J. Larmor on the Theory of Moving Electrons and Electric 



Charges 201 



Notices respecting New Books : — 



Mr. E. T. Glazebrook's ' James Clerk Maxwell and 



Modern Physics ' 205 



Dr. Benjamin Williamson's Elementary Treatise on the 



Integral Calculus 205 



Mr. W. C. Dampier W r hetham's Solution and Electrolysis 206 

 Proceedings of the Geological Society : — 



Mr. Clement Eeid on the Eocene Deposits of Dorset . . 207 

 On the Refractive Indices of some Substances for very short 



Electrical Waves, by Dr. A. Lampa 207 



A Lecture Experiment on Diathermancity, by Dr. Silvio 

 Lussano 208 



