CONTENTS. vii 



XVIII. On the Approximation to the Roots of Cubic Equations by help 

 of Recurring Chain-Fractions. By Edward Sang, LL.D., 

 F.E.S.E, 311 



XIX. On Knots. Part II. By Professor Tait, Sec. E.S.E. (Plate 



XLIV.), 327 



Appendix. — Note on a Problem in Partitions. By Professor 

 Tait, Sec. E.S.E., ...... 340 



XX. On the Philosophy of Language. By Emeritus Professor 



Blackie, F.E.S.E., . . . . . . 343 



XXI. The Old Red Sandstone Volcanic Rocks of Shetland. By 

 B. N. Peach, F.E.S.E., and John Horne, F.E.S.E. (Plates 

 XLV, XL VI.), 359 



XXII. Observations on a Green Sun and Associated Phenomena. By 



Professor C. Michie Smith, F.E.S.E. (Plate XLVII), . 389 



XXIII. An Example of the Method of Deducing a Surface from a Plane 

 Figure. By Professor L. Cremona, LL.D. Edin., Hon. 

 F.E.SS. Lond. and Edin., . . . . .411 



PAET III. (1884-85.) 



XXIV. Micrometrical Measures of Gaseous Spectra under High Dis- 

 persion. By Professor C. Piazzi Smyth, F.E.S.E., and Astro- 

 nomer-Eoyal for Scotland. (Plates XLVIII.-LXXVIIL), 415 



XXV. On Bipartite Functions. By Thomas Muir, LL.D., . .461 



XXVI. The 364 Unifilar Knots of Ten Crossings, Enumerated and 



Described. By Eev. Thomas P. Kirkman, M.A., F.E.S, . 483 



XXVII. On Knots. Part III. By Professor Tait. (Plates LXXIX.- 



LXXXL), . . . . . .493 



XXVIII. A New Graphic Analysis of the Kinematics of Mechanisms. 

 By Professor Eobert H. Smith, Mason College, Birming- 

 ham. (Plate LXXXIL), . . . . .507 



