CONTENTS. Vll 



PART II. 



XIII. On the Determination of the Position of Strata in Stra- 

 tified Rocks. By L. A. NECKER, Honorary Professor of 

 Mineralogy and Geology in the Academy of Geneva, &c. 363 



XIV. On the Equations of Loci traced upon the Surface of the 



Sphere, as expressed by Spherical Co-ordinates. By 

 THOMAS STEPHENS DAVIES, Esq. F. R. S. Lond. & Ed. 

 F. R. A. S. - 379 



XV. Experimental Researches regarding certain Vibrations 

 which take place between Metallic Masses having dif- 

 ferent Temperatures. By JAMES D. FORBES, Esq. 

 F. R. SS. L. & Ed., Professor of Natural Philosophy in 

 the University of Edinburgh, - 429 



XVI. Observations on the Natural History of the Salmon, 

 Herring, and Vendace. By ROBERT KNOX, F. R. S. 

 Ed. ----- -462 



XVII. Observations on the Lines of the Solar Spectrum, and on 

 those produced by the Earths Atmosphere, and by the 

 action of Nitrous Acid Gas. By Sir DAVID BRE WSTER, 

 K. H. LL. D. F. R. S. Lond. V. P. R. S. Ed. 51 9 



XVIII. Abstract of a Paper accompanying a Suite of Volcanic 

 Rocks from the Lipari Islands, presented to the Royal 

 Society. By ROBERT ALLAN, Esq. F. R. S. Ed. M. G. S. 

 SEC. - 531 



