Intelligence and Miscellaneous Articles, 291 



drift, although composed of local materials, was probably of sub- 

 aqueous origin, and not merely subaerial. The discovery of a granite 

 boulder might, if confirmed by other discoveries, lead to a modifica- 

 tion of the views generally held as to the physical character of the 

 area during the glacial period. 



8. "Report on Palseo-botanical Investigations of the Tertiary 

 Flora of Australia." By Dr. Constantin Baron von Ettingshausen, 

 For.Corr.G.S. 



9. " On some new Features in Pelanechinus corallinus" By T. 

 T. Groom, Esq. 



10. " On Boulders found in Seams of Coal." By John Spencer, 

 Esq., F.G.S. 



The discovery of a boulder weighing 6 lbs., and composed of 

 granite, in the Gannister or Mountain-Mine seam of the Hossendale 

 district, at Old Meadows Pit, near Bacup, Lancashire, had led the 

 Author to call attention to the occasional occurrence of similar 

 boulders in various parts of Lancashire and Yorkshire. Such 

 boulders were always isolated, and sometimes imbedded in the seam, 

 sometimes in its upper surface. They were always waterworn and 

 rounded, and were composed, so far as had been observed, of granite, 

 gneiss or quartzite foreign to the district. 



After considering the various suggestions that had been made as 

 to the means by which such boulders had found their way into the 

 coal, the Author gave the preference to the action of floating ice, 

 both because the presence of fragments from a distance would thus 

 be more readily explained, and because ice-scratched rocks have been 

 found in situ in the Millstone Grit within three miles of the place 

 whence the boulder mentioned was obtained. 



XXXVII. Intelligence and Miscellaneous Articles. 



ON THE OCCURRENCE OF ELECTROMOTIVE FORCES IN METAL 

 PLATES WHICH ARE TRAVERSED BY A CURRENT OF HEAT 

 WHILE PLACED IN THE MAGNETIC FIELD. BY A. VON ET- 

 TINGSHAUSEN AND W. NERNST. 



TN the course of our observations of Hall's phenomenon, we 

 ■*- were led by certain irregularities to make the following expe- 

 riments. 



A rectangular plate of bismuth about 5 centim. in length, 4 

 centim. broad, and 2 centim. thick, provided in the longer sides 

 with two electrodes opposite each other, is brought into the field 

 of an electromagnet in such a way that the lines of force cut the 

 plane of the plate at right angles. This is supported by being 

 clamped at the shorter sides in strips of copper, but protected from 

 direct contact with the latter by plates of mica. * 



When one or the other copper strip is heated, a current of heat 

 traverses the plate lengthwise. When the magnetic field of the 



