IV CONTENTS OF VOL. XLV1II. FOURTH SERIES. 



NUMBER CCCXYL— AUGUST. 



Page 

 Mr. "W". Orookes on Attraction and Bepulsion accompanying 



Eadiation. (With a Plate.) 81 



Mr. J. O'Kinealy on Fourier's Theorem 95 



Baron N. Schilling on the Constant Currents in the Air and 



in the Sea : an Attempt to refer them to a common Cause 97 

 Prof. M'Leod on an Apparatus for the Measurement of Low 



Pressures of Gas 110 



Dr. W. H. Stone on "Wind-pressure in the Human Lungs du- 

 ring Performance on Wind Instruments 113 



Dr. W. H. Stone on the Pall in Pitch of Strained "Wires 



through which a Galvanic Current is passing 115 



Mr. H. G. Madan on an Improvement in the Construction 



of the Spectroscope 116 



Mr. L. Schwendler on the General Theory of Duplex Tele- 

 graphy 117 



Dr. W. H. Stone on a simple Arrangement by which the Co- 

 loured Bings of Uniaxial and Biaxial Crystals may be shown 



in a common Microscope 138 



Prof. W. P. Barrett on the Modification of the usual Trombone 

 Apparatus for showing the Interference of Sound-bearing 



Waves ^ 139 



Notices respecting New Books : — 



M. J. Plateau's Statique Experimentale et The'orique des 



Liquides soumis aux seules Forces Moleculaires 140 



Mr. W. B. Birt's Contributions to Selenography 141 



Proceedings of the Boyal Society : — 



Dr. A. C. Bamsay on the Comparative Value of certain 

 Geological Ages (or groups of formations) considered 



as items of Geological Time 143 



Prof. O. 'Beynolds on the Forces caused by Evaporation 



from, and Condensation at, a Surface 146 



Proceedings of the Geological Societv : — 



Prof. W. H. Flower on the Skull of a Species of Haliilw- 



rium from the Bed Crag of Suffolk 153 



Mr. H. Woodward on Forms intermediate between Birds 



and Eeptiles 154 



Mr. J. W. Hulke on the Astragalus of IguanodonMantetti; 

 and on a very large Saurian Limb -bone from the Kim- 



meridge Clay of Weymouth, Dorset 155 



On a Simple Ocular-Spectroscope for Stars, by F. Zollner . . 156 

 Note on the Cause of Tides, byE. J. Chapman, Ph.D., Professor 

 of Mineralogy and Geology in University College, Toronto. 157 



On the Temperature of the Sun, by J. Violle 158 



On a Peculiar Phenomenon in the Path of the Electric Spark, 

 by Prof. Toepler, of Graz 160 



