CONTENTS (continued). 



PAGE 



III. Contributions to the Study of the Errant Annelides of the Older Palaeozoic 

 Eocks. By H. Alleyne Nicholson, M.D., D.Sc, M.A., Ph.D., F.E.S.E., 

 Professor of Natural History in University College, Toronto .... 288 



May 15, 1873. 



I. Determination' of the Number of Electrostatic Units in the Electromagnetic 

 Unit made in the Physical Laboratory of Glasgow University. By 

 Dugald M'KlCHAN, M.A 290 



II. On Jeypoorite, a Sulph-antimonial Arsenide of Cobalt. By Major W. A. 



Eoss, late Eoyal Artillery 292 



III. On a. Periodicity of Eainfall in connexion with the Sun-spot Periodicity. 



By C. Meldettm, Director of the Meteorological Observatory, Mauritius 297 



IV. On the Heating of a Disk by rapid Eotation in vacuo. By Baleotjb 



Stewabt, M.A., E.E.S., Professor of Natural Philosophy in Owens 

 College, Manchester, and P. G. Tait, M.A., Professor of Natural Philo- 

 sophy in the University of Edinburgh 309 



V. On the Extension of the Numerical Value of ir. By William Shanks . 318 



List of Presents 320 



CATALOGUE OF SCIENTIFIC PAPEES. 

 Vol. VI., completing the Work, is published. 

 Vols. I. -VI. are always on sale. 



EEEATA ET COEEIGENDA. 



Page line 



214, 5 from bottom, for accessible read sensible. 

 216, 22 „ top, for opposite read consequent. 

 J} 26 „ „ for Whenever read However. 

 27 „ j, for is read be. 



243, 1 „ „ for rod-like read rod-shaped. 



244, 22 „ „ for corroborated read corroborative. 



TAYLOE AND FEANCIS, EED LION COUET, FLEET STEEET. 



