DR. SIEMENS' THEORY OF TEE SUN. 39 



publishing all at once an octavo volume of 240 pages, which 

 has proved too formidable even to many of those who arc 

 specially interested in the subject. 



I am compelled to infer that this is the reason why so 

 many of the speculations, which were physical heresies 

 when expounded therein, have since become so generally 

 adopted, without corresponding acknowledgment. This is 

 not the place for specifying the particulars of such adop- 

 tions, but I may mention that in due time "An Appendix 

 to the Fuel of the Sun," including the whole history of the 

 subject, will be published. The materials are all in hand, 

 and only await arrangement. In the meantime I will 

 briefly state some of the points of agreement and difference 

 between Dr. Siemens and myself. 



In the first place, we both take as our fundamental basis 

 of speculation the idea of an universal extension of atmos- 

 pheric matter, and we both regard this as the recipient of 

 the diffused solar radiations, which are afterwards recovered 

 and recondensed, or concentrated. Thus our " fuel of the 

 sun" is primarily the same, but, as will presently be seen, 

 our machinery for feeding the solar furnace is essentially 

 different. 



Certain desiccated pedants have sneered at my title, "The 

 Fuel of the Sun," as " sensational," and have refused to 

 read the book on this account; but Dr. Sterry Hunt has 

 provided me with ample revenge. He has disentombed an 

 interesting paper by Sir Isaac Newton, dated 1675, in which 

 the same sensationalism is perpetrated with very small mo- 

 dification, Sir Isaac Newton's title being " Solary Fuel." 

 Besides this, his speculations are curiously similar to my 

 own, his fundamental idea being evidently the same, but 

 the chemistry of his time was too vague and obscure to ren- 

 der its development possible. This paper was neglected 

 and set aside, was not printed in the Transactions of the 

 Eoyal Society, and remained generally unknown till a few 

 months ago, when the energetic American philosopher 

 brought it forth, and discussed its remarkable anticipations. 



Dr. Siemens supposes that the rotation of the sun effects 

 a sort of "fan action," by throwing off heated atmospheric 

 matter from his equatorial regions, which atmospheric 



