PROCEEDINGS 
OF THE 
ROYAL SOCIETY OF EDINBURGH. 
SESSION 1921-22 
Part III] YOL. XLII. [PP- 257-464 
(Contains Title, Contents, and Index.) 
CONTENTS. 
XVIII. On the Application of the Gyroscope to the Solutioiy'lgf'S&ie 
“Vertical” Problem on Aircraft. Part I. James 
Gordon Gray, D.Sc., Cargill Professor of Appliedlftiysies-^ 1 ^ 1 
in the University of Glasgow ; and Captain j\ Gray, 
A.M.I.E.E. (late KA.F.). 
(Issued se'paratehj August 10, 1922.) 
XIX. Elliptic Expansions. By Mr R. T. A. Innes, . 
(Issued separately August 10, 1922.) 
318 
XX. On Self Light, Fatigue, Inhibition, and Recurrent Visual 
Images. By Professor W. Peddie, D.Sc., .... 31D 
(Issued separately August 10, 1922.) 
XXI. On the Dominance Ratio. By R. A. Fisher, M.A., Fellow of 
Gonville and Cains College. Communicated by Professor 
J. Arthur Thomson, 321 
(Issued separately October 16, 1922.) 
XXII. Note on a Theorem of Frobenius’ connected with Invariant- 
Factors. By Sir Thomas Muir, F.R.S., .... 342 
(Issued separately October 16, 1922.) 
XXIII. Notes on a Correspondence between the French Academy of 
Sciences and the Royal Society of Edinburgh regarding 
the Invention of the Pilot Cable (Cable Guide). By The 
General Secretary, 348 
(Issued separately October 16, 1922.) 
XXIV. Chemical Combination and Sir Alfred Ewing’s Magnetic 
Atom. By Principal A. P. Laurie, M.A., D.Sc., . . 352 
(Issued separately November 14, 1922.) 
[Continued on page iv of Cover. 
EDINBURGH: 
Published by ROBERT GRANT & SON, 126 Peincks Street, and 
williams & NORGATE, 14 Henrietta Street, Covent Garden, London, W.C. 2. 
Price Thirteen Shillings. 
