CONTENTS. Vll 



Page 

 Report of the Committee, consisting of Professor Sir H. E. Roscoe, Mr. J. N. 

 Lockyer, Professors Dewar, "Wolcott Gibbs, Liyeing, Schuster, and AY. 

 N. Hartley, Captain Abney, and Dr. Marshall Watts (Secretary), ap- 

 pointed for the purpose of preparing a new series of "Wave-length Tables of 

 the Spectra of the Elements 351 



On the Connection between Sunspots and Terrestrial Phenomena. By Pro- 

 fessor Schuster, F.R.S 446 



On the Seat of the Electromotive Forces in the Voltaic Cell. By Professor 

 Oliver J. Lodge, D.Sc 464 



On the Archaean Rocks of Great Britain. By Professor T. G. Bonnet, D.Sc, 

 LL.D., F.R.S., Pres. G.S 529 



On the Concordance of the Mollusca inhabiting both sides of the North Atlantic 

 and the intermediate Seas. By J. Gwyn Jeffreys, LL.D., F.R.S 551 



On the Characteristics of the North American Flora. By Professor Asa 

 Gray 555 



On the Theory of the Steam-Engine. By Professor Robert H. Thurston . . . 569 



Improvements in Coast Signals ; with Supplementary Remarks on the New 

 Eddystone Lighthouse. By Sir James N. Douglass, M.Inst.C.E 584 



On American Permanent Way. By JosErH M. "Wilson, A.M., M.Inst.C.E. 593 



