IV CONTENTS OF VOL. XL. FOURTH SERIES. 



Page 

 Dr. P. M. Duncan on the Physical Geography of Western 



Europe during the Mesozoic and Cainozoic Periods. ... 71 

 Mr. T. Davidson on the Brachiopoda hitherto obtained from 



the Pebble-bed at Budleigh-Salterton 71 



Mr. S. V. Wood, Jun., on the Relation of the Boulder-clay 

 without Chalk of the North of England to the Great 



Chalky Boulder-clay of the South 72 



Mr. R. Tate and Dr. J. S. Holden on the Iron-ores asso- 

 ciated with the Basalts of the North-east of Ireland . . 73 



Principal Dawson on the Structure of Sigillaria 74 



Principal Dawson on some new Animal Remains from the 



Carboniferous and Devonian of Canada 75 



Mr. J. W. Hulke on a Crocodilian Skull from Kimmeridge 



Bay, Dorset 75 



Mr. J. W. Hulke on some Teeth associated with two 



fragments of a Jaw from Kimmeridge Bay 76 



Experiments on the Velocity of the Propagation of Sound in 

 Water in a Cast-iron Conduit 8 decimetres in diameter, by 



M. Fr. Andre 76 



Experimental Researches on the Duration of the Electric Spark, 

 by MM. Lucas and Cazin 78 



NUMBER CCLXV.— AUGUST. 



M. Achille Cazin on Internal Work in Gases. (With a Plate.) 81 



Mr. W. M. Watts on the Spectra of Carbon 100 



Dr. W. J. M. Rankine on Thermodynamics 103 



M. W. Wernicke on the Refractive Indices and the Dispersion 



of Opaque Bodies 105 



Mr. G. M. Seabroke on the Determination whether the Corona 



is a Solar or Terrestrial Phenomenon 117 



Prof. R. Clausius on a Mechanical Theorem applicable to Heat. 122 

 Proceedings of the Royal Society : — 



Sir C. Wheatstone on a Cause of Error in Electroscopic 



Experiments 128 



Mr. W. H. Barlow on the Cause and Theoretic Value of 



the Resistance of Flexure in Beams 130 



Staff-Commander J. E. Davis on Deep-sea Thermometers. 132 

 Dr. E. J. Mills on the Chemical Activity of Nitrates .... 134 

 Proceedings of the Geological Society : — 



Mr. R. Etheridge on the Geological Position and Geogra- 

 phical Distribution of the Reptilian or Dolomitic Con- 

 glomerate of the Bristol Area 136 



Mr. T. G. B. Lloyd on the Superficial Deposits of portions 



of the Avon and Severn Valleys 137 



Mr. J. Prestwich on the Crag of Norfolk and associated Beds. 137 

 Dr. P. M. Duncan on the Fossil Corals (Madreporaria) of 



the Australian Tertiary Deposits 139 



Mr. J. W. Hulke on a new and undescribed Wealden Ver- 

 tebra 140 



