IV CONTENTS OF VOL. III. FIFTH SERIES. 



Page 

 Note on the Correction of the Variations of Rate of Astro- 

 nomic Pendulums proceeding from differences of Atmo- 

 spheric Pressure, by A. Redier 80 



NUMBER XVI.— FEBRUARY. 



Mr. S. W. Holnian on a New Method of Studying the Rela- 

 tion between the Viscosity and Temperature of Gases .... 81 

 Mr. J. W. Draper on the Fixed Lines in the Ultra-red Invi- 

 sible Region of the Spectrum 86 



Dr. K. Heumann's Contributions to the Theory of Lnminous 



Flames.— Part II 89 



Mr. R. Mallet on the Conversion of the Geyser-throats in 



Iceland into Volcanic Vents 108 



Dr. "W. P. Hillebrand on the Specific Heats of Cerium, Lan- 

 thanum, and Didymium 109 



Dr. E. Bouty on the Magnetization of Steel by Currents .... 119 

 Mr. N. S. Maskelyne on the Optical Characters of Ludlamite. 135 



Mr. T. Muir on a Theorem in Continuants 137 



Mr. P. Guthrie on a Sensitive Mercury Barometer 139 



Notices respecting New Books : — 



Dr. W. Fleming's Vocabulary of Philosophy, Mental, 

 Moral, upA Metaphysical : with quotations and refer- 

 ences for the use of Students 141 



Proceedings of the Royal Society : — 



Mr. "W. Spottiswoode on Stratified Discharges. — II. Ob- 

 servations with a Revolving Mirror 144 



Proceedings of the Geological Society : — 



Prof. T. McKenny Hughes on the Silurian Grits near 



Corvven, North Wales 153 



Mr. W. Morgan on Mineral Veins 154 



The Rev. J. F. Blake and Mr. W. H. Hudleston on the 



Corallian Rocks of England 154 



Note on Mr. Lodge's Paper "Ona Mechanical Illustration 



of Thermo-electric Phenomena," by Prof. M. Avenarius . . 156 

 On an Arrangement for Reproducing, with the aid of the 

 Siren, the Experiment of Foucault (arrest of a Rotating 

 Disk under the Action of an Electromagnet), by M. Bour- 



bouze 157 



Observations on a Property of the Retina, first noticed by Tait, 



by Ogden N. Rood, Professor of Physics in Columbia College 158 

 On some Effects of Heat upon Voltaic Circuits completed by 

 an Electrolyte, by W. Hellesen, of Copenhagen 159 



