[ iv ] 
Vr. The Sj^ectra of Neon, Krypton rmd Xenon. By E. C. C. Baly, Lecturer on 
Spectroscoj)y in University College, London, Comniumcated /;?/<Sn' illtam 
V^am^ky,K.C.B.,F.R.S. .183 
\^IL On the Discharge of Electricity from Hot Platinum. By Harold A. Wilsox, 
D.Sc., B.A., Felloiv of Trinity College, Camhridge. Communicated by 
C. T. Pv. Wilson, FR.S . -^3 
VIII. The Differential Invariants of Space. By A. B Eoesyth, Sc.D., LED., 
F.R.S., Sadlerian Professor of Pure Mathematics in the University of 
Cambridge . 
IX. An Analysis of the Results from the Kew Magnetographs on “Quiet” Days 
during the Eleven Years 1890 to 1900, ivith a Discussion of Certain 
Phenomena in the Absolute Observations. By Charles Chree, Sc.D., LL.D., 
F.R.S., Superintendent of the Observatory DepKirtment of the National 
Physical Laboratory. [From the Nationcd Physical Laboratory.). . . 335 
X. On the Photo-Electric Discharge from Metallic Surfaces in Different Gases. By 
W. Mansergh Varley, M.Sc. {Viet.), Ph.D. {Strasburg), B.A. [Cantab.); 
late 1851 Exhibition Research Scholar, Emmanuel College, Cambridge; 
Assistant Professor oj Physics and Electrical Erigineemng, Ileriot-Watt 
College, Edinburgh. Communicated by I^rofessor I. J. Thomson, F.R.S. 439 
XL An Encjuiry into the Variation of Angles observed in Crystals; especicdly of 
Potassium-edum and Ammonium-alum. By Henry A. Miers, D.Sc., M.A., 
F.R.S., V.P.G.S., V.P.C.S., Waynflete Professor of Mineralogy in the 
University of Oxford . 359 
XH. Radiation in the Solar System: its Effect on Temperature and its Pressure on 
Small Bodies. By J. H. Poynting, Sc.D., F.R.S., Professor of Physics in 
the University of Birmingham. ... . 525 
Index to Volume 
553 
