CONTENTS. 
X. On the Mathematical Theory of Stream-lines , especially those with four Foci and 
upwards. By William John Macquorn Rankine, C.E., LL.D ., F.B.SS. Lond. 
& Edin., &c page 267 
XI. Records of the Magnetic Phenomena at the Kew Observatory. — No. IV. Analysis 
of the Principal Disturbances shown by the Horizontal and Vertical Force Magne- 
tometers of the Kew Observatory, from 1859 to 1864. By General Sir Edward 
Sabine, K.C.B., President 307 
XII. On Fluoride of Silver . — Part II. By George Gore, F.R.S 321 
XIII. On the Constitution of the Solid Crust of the Earth. By Archdeacon Pratt, 
M.A., F.R.S. 335 
XIV. On the Mineral Constituents of Meteorites. By Nevil Story-Maskelyne, M.A., 
F.R.S., Professor of Mineralogy, Oxford, and Keeper of the Mineral Department, 
British Museum 359 
XV. On the Problem of the In-and- Circumscribed Triangle. By A. Cayley, F.R.S. 369 
XVI. On the Unequal Distribution of Weight and Support in Ships, and its Effects in 
Still Water, in Waves, and in Exceptional Positions on Shore. By E. J. Reed, 
C.B., Vice-President of the Institution of Naval Architects. Communicated by 
Professor G. G. Stokes, Sec. R.S. . 413 
XVII. On the Measurement of the Chemical Intensity of Total Daylight made at Catania 
during the Toted Eclipse of Dec. 22nd, 1870. By Henry E. Roscoe, F.R.S., 
Professor of Chemistry, Owens College, Manchester, and T. E. Thorpe, F.R.S. E., 
Professor of Chemistry, Andersonian University, Glasgow ...... 467 
XVIII. On the Organization of the Fossil Plants of the Coed-measures . — Part I. Cedei- 
mites. By W. C. Williamson, F.R.S., Professor of Natural History in Owens 
College, Manchester 477 
XIX. Description of Ceratodus, a genus of Ganoid Fishes, recently discovered in rivers of 
Queensland, Australia. By Albert Gunther, M.A., Ph.D., M.D., F.R S. 511 
XX. Measurements of Specific Inductive Capacity of Dielectrics, in the Physical Labo- 
ratory of the University of Glasgow. By John C. Gibson, M.A., and Thomas 
Barclay, M.A. Communicated by Sir William Thomson, F.R.S. . . . 573 
XXI. On Cyclides and Sphero-Quartics. By John Casey, LL.D., M.R.I.A. Com- 
municated by A. Cayley, F.R.S. 585 
