348 Scientific Intelligence. 



Beginning, - 21 h 46' .4" M. time. 



End, - 23 58 19 



Mr T. Squires observed it at Epping, in long. 27" of time, east of Green- 

 wich, and north lat. 61° 41' 41" 6. 



End, - - 12* 0' 54 M. Solar time. 



7. Mr Herschel and Captain Sabine's determination of the difference of 

 Meridians of London and Paris. — These able astronomers have deter- 

 mined, by means of signals, that the difference of longitude of London and 

 Paris is 9' 2i".6 in time, or 2° 20' 24" in space. Mr Herschel is of opinion 

 that this result is not likely to be altered a whole tenth of a second in time, 

 and very unlikely to be altered to twice that extent by future observations. 

 An elaborate account of these observations by Mr Herschel will be found 

 in the Phil. Trans. 1826, part ii. p. 127. 



8. Fraunhofer on Halos and Parhelia. — A theory of Halos and Parhelia has 

 been recently published in Professor Shumacher's Astronomische Abhand- 

 lungen, by the late distinguished M. Fraunhofer. He ascribes the small 

 halos round the sun and moon to the inflexion of light by the particles of 

 vapour in the atmosphere, and the halo of 45° to the refraction of the light 

 through hexagonal prisms of ice. From the abstract of this paper, which 

 we have seen, there does not appear to be much novelty in it. Dr Young 

 and others seem to have anticipated the author in all his general results. 

 — See Edinburgh Encyclopaedia, article Halos. 



ELECTRO-MAGNETISM. 



9. Effect of a moving disc on a Voltaic conductor, — M. Ampere has com- 

 municated to the Academy of Sciences an experiment, which proves that a 

 disc in motion exercises a certain action on a yoltaic conductor. The de- 

 tails of the discovery are not published. 



10. On the conducting power of Metals for Electricity,— The following 

 results have been obtained by M. Becquerel. 



11. Noise of the Aurora Borcalis observed by Hearne.— -Having stated 

 in No. ix. p. 74, various authorities for believing that a sound sometimes 

 accompanied the Aurora Borealis, we give the following statement made by 

 Hearne, as an additional argument in favour of that opinion. 



" I do not remember to have met with any travellers into high northern 

 latitudes who remarked their having heard the northern lights make any 



