160 Intelligence and Miscellaneous Articles, 



ON THE ERUPTION THEORY OF THE CORONA, 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



In your Supplementary Number for June last you say (page 537) 

 that " Mr. Proctor has lately broached a theory of solar eruption, in 

 which he considers that the solar coronal matter consists of meteors 

 ejected from the sun, and rushing through the photosphere with a ve- 

 locity of 200 miles per second," &c. 



I presume that Mr. Proctor will be as much surprised as myself at 

 this affiliation, inasmuch as in Fraser's Magazine for April last he 

 discussed this idea as one which " astronomers first saw enunciated 

 in Mattieu Williams's ' Fuel of the Sun/ " and pointed out the confir- 

 mations which the recent observations on the corona, and the actual 

 measurements of eruptive velocities by Zollner, afforded to this ex- 

 planation, which incidentally and unexpectedly forced itself upon me 

 in working out the necessary physical consequences of the unlimited 

 extension of ordinary atmospheric matter in the work to which Mr. 

 Proctor referred. 



As the Philosophical Magazine is one of the permanent records of 

 the progress of science, it is but a matter of justice both to Mr. 

 Proctor and myself that this mistake should be corrected. 



Yours truly, 



W. Mattieu Williams. 



Woodside Green, Croydon, 

 June 20, 1871. 



[Although to a certain extent a similarity may exist between the 

 theory enunciated by Mattieu Williams in his work entitled the 

 ■ Fuel of the Sun ' and that which we have ascribed to Proctor, in 

 some important particulars they differ materially. It is generally 

 understood that the principal material of the solar prominences is 

 glowing hydrogen, which, according to Proctor, rushes outwards 

 through the photosphere in countless exceedingly fine jets. Accord- 

 ing to Williams, the elements of water and metallic vapours are 

 ejected by continuous explosions from the body of the sun during the 

 uprush necessary to restore the equilibrium disturbed by the down- 

 rush forming the spots. Beyond the photosphere, the products 

 of combustion of metallic elements solidify in consequence of a series 

 of condensations, by which metallic snow and hail are produced, filling 

 for a time the coronal space and then are rained back upon the sun. 

 The only point, so far as we can see, in which the two theories agree 

 is that the corona consists of solar matter ; but as to the nature of the 

 materials the theorists differ. — Reviewer.] 



