[ ] 
V. On the Vibrations and Stahdity of a Gramtalincj Planet. By J. H. Jeaxs, B. A. 
Isaac Neinton Student, and Fclloiu of Trinity CoUer/e, Cambridge. Communi¬ 
cated. by Professor G. IL Dakwin, F.R.S .157 
Yf. On the Formation of Definite Figures by the Deposition oj Dust. By Y'. J. 
Eitssell, Ph.D., F.R.S .185 
VIT. The Spectrum ofy Cygni. By Sir Norman Lockyer, K.C.D., F.R.S., and 
F. E. Bax AND ALL, A.R.C.Sc .- 0 5 
YITL Quaternions and Projective Geometry. By Professor Jasper Jota, 
Royal A.stronorner of Ireland. Communicated by Sir Eorert Ball, 
F.R.S. .223 
IX. The Difiercntial Invariants of a Surface, and their Geometric Significance. By 
A. E. Forsyth, jM.A., Sc.D., F.R.S., Sadlerian Pivfessor of Pure Ilithe- 
matics in the University of Cambridge .'^29 
X. On the Lairs Governing Electric Discharges in Gases at Low Pressure.^. By 
AY. E. Carr, B.A., Post-graduate Student, University of Toronto. Communi¬ 
cated by Professor J. J. Thomson, F.R.S. . 
XL On the Dependence of the Refractive Lndex of Gases on Temperature. By 
GEORC4 E W. Walker, M.A., A.R.C.Sc., Fellow of Trinity College, Cambridge. 
Communicated, by Professor J. J. Thomson, I.R.S .4-j5 
XTI. Solar Eclipse r/ 1900, 2 ^.—General Discu.‘^sion of Sjyectroscopic Results. 
By J. Eyershed, F.R.A.S. Communicated by the Joint Permanent Eclipse 
.. 
XITL Ihe Electrical Conductirity Imparted to a Vaciiurn by Hot Conductors. By 
O. AY. Eichardson, B.A., B.Sc., Fellow of Trinity College, Cambridge. 
Communicated by Professor J. J. Tikaison, I.R.S .497 
XIY. On. the Formation of Definite Figures by the Deposition of Dust. 7L/ John 
Attken, F.R.S . 
Index to Volume 
559 
