[ iv ] 
XI. Results of Observations of Atmospheric Electricity at Kew Observatory , arid at 
King's College , Windsor, Nova Scotia. By Joseph David Everett, D.C.L . , 
F.R.S.E. Communicated by Sir William Thomson, F.R.S. . . . page 347 
XII. Account of Experiments on Torsion and Flexure for the Determination of 
Rigidities . — Third Paper. By Joseph David Everett, D.C.L. , Professor of 
Natural Philosophy in Queen's College, Belfast. Communicated by Sir William 
Thomson, F.R.S 363 
XIII. Contributions to Terrestrial Magnetism. — No. XI. By Lieut. -General Edward 
Sabine, R.A., President of the Royal Society 371 
XIV. On the Resistance of the Air to the Motion of Elongated Projectiles having variously 
formed Heads. By E. Bashforth, B.D., Professor of Applied Mathematics to 
the Advanced Class of Artillery Officers, Woolwich, and late Fellow of St. John's 
College, Cambridge. Communicated by Professor Stokes, Sec. R.S. . . . 417 
XV. On the Law of the Resistance of the Air to Rifled Projectiles. By Charles W. 
Merrifield, F.R.S., Principal of the Royal School of Naval Architecture . 443 
XVI. On the Communication of Vibration from a Vibrating Body to a surrounding Gas. 
By G. G. Stokes, M.A., D.C.L., Sec. R.S., Fellow of Pembroke College, and 
Lucasian Professor of Mathematics in the University of Cambridge . . . 447 
XVII. Comparison of Magnetic Disturbances recorded by the Self-registering Magneto- 
meters at the Royal Observatory, Greenwich, with Magnetic Disturbances deduced 
from the corresponding Terrestrial Galvanic Currents recorded by the Self-regis- 
tering Galvanometers of the Royal Observatory. By George Biddell Airy, 
Astronomer Royal, F.R.S 465 
XVIII. On the Relation of Form and Dimensions to Weight of Material in the Construction 
of Iron-clad Ships. By E. J. Peed, Chief Constructor of the Navy. Commu- 
nicated by Professor G. G. Stokes, Sec. R.S. 473 
XIX. On the Amount and Changes of the Polar Magnetism at certain positions in Her 
Majesty' s Iron-built and Armour-plated Ship ‘ Northumberland .' By Frederick 
John Evans, Staff Captain, R.N., F.R.S., Chief Naval Assistant, Hydrographic 
Department, Admiralty * 487 
XX. Contributions towards determining the Weight of the Brain in different Races of 
Man. By Joseph Barnard Davis, M.D., &c. Communicated by J. Marshall, 
F.R.S. 505 
XXI. Further Observations on the Spectra of some of the Stars and Nebulae, with an 
Attempt to determine therefrom whether these Bodies are moving towards or from 
the Earth, also Observations on the Spectra of the Sun and of Comet II., 1868. 
By William Huggins, F.R.S. 529 
