CONTENTS of N° SO*.— Fourth Series. 



X. Fluorescent Eelations of certain solid Hydrocarbons found in 

 Petroleum Distillates. By Henry Morton, Ph.D., President of the 

 Stevens Institute of Technology page 89 



XI. On the Form of the Cells of Bees. By J. W. L. Glaisher, 

 B.A., Fellow of Trinity College, Cambridge 103 



XII. On the Integration of the Accurate Equation representing 

 the Transmission in one direction of Sound through Air, deduced 

 on the Ordinary Theory. By Eobert Moon, M.A., Honorary Fel- 

 low of Queen's College, Cambridge 122 



XIII. On some Results of the Earth's Contraction from Cooling, 

 including a discussion of the Origin of Mountains. By James D. 

 Dafa 131 



XIY. On Magnetic Permeability, and the Maximum of Magnetism 

 of Iron, Steel, and Nickel. By Henry A. Eowland, Instructor in 

 Physics in the Eensselaer Polytechnic Institute, Troy, N.Y. (With 

 Two Plates.) 140 



XV. On Objections recently made to the received principles of 

 Hydrodynamics. By Professor Challis, M.A., LL.D., F.E.S., 

 F.E.A.S 159 



XVI. On the Nodal Lines of a Square Plate. By Lord Eayleigh, 

 F.E.S. (Hon. J. W. Strutt) 166 



XVII. Notices respecting New Books : — Astronomical and Me- 

 teorological Observations made during the year 1870, at the United- 

 States Naval Observatory 171 



XVIII. Proceedings of Learned Societies : — 



Geological Society : — Mr. C. J. A. Meyer on the Punfield 

 Section ; Mr. W. J. Sollas on the Coprolites of the Upper 

 Greensand Formation, and on Flints 173-174 



XIX. Intelligence and Miscellaneous Articles : — 



On a new Method for examining the divisions of Graduated 

 Circles, by G. Quincke 174 



On a convenient Eyepiece-micrometer for the Spectroscope, by 

 Professor 0. N. Eood : 176 



On Jamin's Compound Magnets, by E. S, Culley, Esq 176 



It is requested that all Communications for this Work may be addressed, 

 post-paid, to the Care of Messrs. Taylor and Francis, Printing Office, Red 

 Lion Court, Fleet Street, London. 



