PROCEEDINGS OF 

 THE KOYAL SOCIETY. 



vol. xx. No. 135. 



/ A CONTENTS. 



7 May 2, 1872. 



PAGE 



On a new Great Theodolite to be used on the Great Trigonometrical Survey 

 of India, with a short Note on the performance of a Zenith-Sector employed 

 on the same work. By Lieut. -Colonel A. Strange, F.R.S., Inspector of 

 Scientific Instruments, India Department 317 



II, On some Elementary Principles in Animal Mechanics. — No. V. On the most 

 perfect form of a Plane Quadrilateral Muscle connecting two Bones. By 

 the Eev. Samuel Haughton, F.R.S., M.D. Dubl., D.C.L. Oxon., Fellow 

 of Trinity College, Dublin 328 



III. On some Elementary Principles in Animal Mechanics. — No. VI. Theory of 

 Skew Muscles, and investigation of the conditions necessary for Maximum 

 Work. By the Eev. Samuel Haughton, F.R.S., M.D. Dubl., D.C.L. 

 Oxon., Fellow of Trinity College, Dublin 330 



IV. On the Rings produced by Crystals when submitted to Circularly Polarized 



Light. By William Spottiswoode, M.A., Treas. & VP.R.S 333 



May 16, 1872. 



I. On the Specific Heat and other physical characters of Mixtures of Methylic 

 Alcohol and Water, and on certain relations existing between the Specific 

 Heat of a Mixture or Solution and the Heat evolved or absorbed in its 

 formation. By A. Dupre, Ph.D., Lecturer on Chemistry at the Westminster 

 Hospital 336 



II. On Supersaturated Saline Solutions. Part III. — On a relation between the 

 Surface-tension of Liquids and the Supersaturation of Saline Solutions. By 

 Charles Tomlinson, F.R.S., and Q-. Van dee Mensbrugghe .... 342 



III. Remarks on the Sense of Sight in Birds, accompanied by a description of the 

 Eye, and particularly of the Ciliary Muscle, in three species of the Order 

 Rapaces. By Robert James Lee, M.A., M.D 351 



Supplement, containing a Description of the Eye in Rhea americana, 

 Phoznicopterus antiqicorunt, and Aptenodytes Humboldtii .... 35* 



[For continuation of Contents see 4£h page of Wrapper. ,] 



