VIU CONTENTS. 



Page 

 Mr. W. Froude's Mechanical Theory of the Soaring of Birds 31 



Professor F. Guthbie and Dr. F. Guthrik on the Passage of Fluids through 



Capillary and other Tubes 31 



Professor J. Purser on the Modification of the Motion of Waves produced by 



Fluid Friction .* 31 



Lord Rayt.eigh on the Forces experienced by a Lamina immersed obliquely 



in a Fluid Stream 31 



Professor Osborne Reynolds on the Resistance encountered by Vortex 

 Rings, and the Relation between the Vortex Ring and Stream-lines of a 



Disk 31 



Dr. C. W. SiEMENs's Description of the Bathometer 31 



Mr. G. Johnstone Stoney on the Amplitude of Waves of Light and Heat . 31 

 on Acoustic Analogues to Motions in the Mole- 

 cules of Gases 31 



Professor James Thomson on the Origin of Windings of Rivers in Alluvial 



Plains 31 



■ on Metric Units of Force, Energy, and Power, 



larger than those on the Centimetre-Gram-Second System 32 



Sir W. Thomson on the Precessional Motion of a Liquid 33 



on the Laws of the Diffiision of Liquids 35 



on a new case of Instability of Steady Motion 35 



on the Nutation of a Solid Shell containing Liquid 35 



Light and Heat. 



Captain Abney's Photometric Measurements of the Magneto-electric Light . 36 



Mr. J. T. BoTTOMLEY on the Conductivity of Heat by Water 36 



Mr. Howard Grttbb on the Testings of Large Objectives 36 



on Recent Improvements in Equatorial Telescopes .... 37 



on a Method of Photographing the Defects in Optical 



Glass arising from want of Homogeneity 37 



Professor Hennessy on the Decrease of Temperature with Height on the 



Earth's Surface 39 



on the Distribution of Temperature over the British 



Islands 39 



Dr. J. Janssen sur les Usages du Revolver Photographique en Astronomic et 



en Biologic 40 



, Photographies du Passage de V^nus a Kob^ 40 



sur le Mirage en Mer 40 



on Solar Photography, with reference to the History of the 



Solar Surface 40 



on the Eclipse of the Sun observed at Siam in April 1875 . . 40 



Mr. John Kerr on Rotation of the Plane of Polarization by Reflection from 



a Magnetic Pole 40 



Mr. W. Ladd's Description of Spottiswoode's Pocket Polarizing Apparatus . . 41 



Professor G. G. Stokes on a Phenomenon of Metallic Reflection 41 



Electricity. 



Professors Ayrton and Perry on the Contact Theory of Voltaic Action 42 



Professor J. Dewar on a new Form of Electrometer 42 



Mr. Oliver J. Lodge on a Mechanical Illustration of Electric Induction and 

 Conduction 42 



on a Mechanical Illustration of Thermoelectric Pheno- 

 mena 43 



